Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 7 April 2021 – 13 April 2021

Aira – Kyushu (Japan) : JMA reported that at 0641 on 5 April and explosion at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) produced an ash plume that rose as high as 3 km above the crater rim and ejected material 800-1,000 m away from the crater. Five explosions were recorded during 9-12 April. The highest ash plume rose 2.1 km and bombs were ejected as far as 900 m from the crater. Crater incandescence was visible nightly. The Alert Level remained at 3 (on a 5-level scale).

Dukono – Halmahera (Indonesia) : PVMBG reported that during 6-10 April ash plumes from Dukono rose 100-700 m above the summit and drifted E, SE, and S. Weather conditions prevented visual observations during 11-12 April. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Ebeko – Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 2-9 April that sent ash plumes to 4.5 km (14,800 ft) a.s.l. and drifted in multiple directions. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Ibu – Halmahera (Indonesia) : PVMBG reported that during 6-13 April gray-and-white ash plumes from Ibu rose 200-1,000 m above the summit and drifted mainly N, E, and S. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater and 3.5 km away on the N side.

Kilauea – Hawaiian Islands (USA) : HVO reported that the W vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 31 March-6 April. Lava flowed at a low rate from the main vent into the lake through crusted-over channels and submerged inlets. The total depth of the lake measured about 226 m and lava continued to circulate in the W part; the E half of the lake remained solidified and expanded toward the W. The sulfur dioxide emission rate was 1,200 tons/day on 1 April. HVO field crews observed weak spattering from two areas at the W vent during 1-2 April. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Lewotolok – Lembata Island (Indonesia) : PVMBG reported that the Strombolian eruption at Lewotolok continued during 6-13 April. Gray-and-white ash plumes rose as high as 750 m above the summit and drifted in multiple directions. Incandescent material was ejected 300-500 m above the summit on most days and 500 m SE on 8 April. Incandescent material was ejected to the E during 9 and 11-12 April. Rumbling was occasionally audible. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 4 km away from the summit crater.

Merapi – Central Java (Indonesia) : BPPTKG reported that the lava dome just below Merapi’s SW rim and the lava dome in the summit crater both continued to grow during 1-8 April. The SW rim lava-dome volume was an estimated 1,098,000 cubic meters on 7 April, with a growth rate of about 12,800 cubic meters per day, and continued to shed material down the flank. A total of 13 pyroclastic flows traveled a maximum of 1.5 km down the SW flank. Incandescent avalanches, recorded 119 times, traveled as far as 1.1 km down the SW flank. The summit lava dome had grown to 75 m tall. Minor ashfall was reported in Ngipiksari (8 km SSW), Klangon (4 km S), and Deles (3 km SE) on 3 April. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 5 km away from the summit.

Raung – Eastern Java (Indonesia) : PVMBG reported that daily gray-and-white ash plumes rose 50-600 m above Raung’s summit during 6-13 April and drifted mainly N, E, and S. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Semeru – Eastern Java (Indonesia) : PVMBG reported that the eruption at Semeru continued during 7-13 April, though weather conditions often prevented visual confirmation. Gray-and-white ash plumes rose as high as 500 m during 9 and 11-12 April. The Alert Level remained at 2 (on a scale of 1-4), with a general exclusion zone of 1 km and extensions to 5 km in the SSE sector.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 2-9 April. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung – Indonesia : PVMBG reported that the eruption at Sinabung continued during 6-13 April. Weather conditions sometimes prevented visual observations of the volcano, though white fumarolic plumes were visible almost daily rising as high as 700 m above the summit and drifting in multiple directions. An eruptive event on 7 April produced a gray ash plume that rose 1 km. Two eruptive events the next day generated ash plumes that rose as high as 700 m. Avalanches traveled as far as 1.5 km E and SE during 8-11 April. Ash plumes rose 500-1,000 m high on 10 April. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km in the SE sector and 4 km in the NE sector.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the Week 7 April 2021 – 13 April 2021

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that the explosive eruption that began at Karymsky on 3 April continued through 11 April. A thermal anomaly was visible in satellite images during 2-6 April; weather conditions obscured views on other days. The 3 April explosion generated an ash plume that rose to 8.5 km (27,900 ft) a.s.l. and drifted 255 km NE. At 1745 on 11 April explosions produced ash plumes that rose to 4 km (13,100 ft) a.s.l. and drifted at least 65 km SE. The Aviation Color Code was raised to Orange (the second highest level on a four-color scale) on 3 April.

Krysuvik-Trolladyngja – Iceland : IMO reported that the fissure eruption in the W part of the Krýsuvík-Trölladyngja volcanic system, close to Fagradalsfjall on the Reykjanes Peninsula, continued during 7-13 April. Lava from the third fissure flowed S into Geldingadalur and NE towards the Meradalir valley site. Flows from the three fissures connected into one flow field on 7 April. Another new fissure opened at around 0300 on 10 April, halfway between two existing fissures, and all four fissures were simultaneously active. Lava flowed towards Geldingadalur. Gas-rich emission plumes were visible in webcam images rising 1.1-1.3 km (3,600-4,300 ft) a.s.l. At least two new vents opened on 13 April based on webcam views. On 14 April IMO noted that lava was flowing from at least eight vents and unverified reports form the morning suggested two additional vents had opened. Sulfur dioxide gas flux was 29 kilograms per second, comparable to measurements collected during the previous few weeks.

IMO warned visitors that new fissures could open without adequate visible warning, especially in an area just S of Keilir, by Litla-Hrút, where seismicity was concentrated. They also warned of increased gas emissions hazards. The Aviation Color Code remained Orange due to the lack of ash and tephra emissions.

Pacaya – Guatemala : INSIVUMEH reported that the eruption at Pacaya’s Mackenney Crater continued during 7-13 April. Explosions during 6-7 April produced ash plumes that rose 1 km above the summit and drifted 10 km W and SW. Ballistics were ejected 50-150 m above the summit. Explosions during 8-9 and 11-12 April produced ash plumes that rose as high as 1 km and drifted as far as 10 km NE, W, and SW.

The lava flow on the W and SW flanks was 3.7 km long and continued to be fed. Incandescent lava blocks were spalled from the flow front and vegetation was set on fire. The lava advanced W onto the La Breña farm and SW towards El Patrocinio and El Rodeo, near the Campo Alegre farm. On 12 April the flows burned La Breña coffee and avocado plantations. By 13 April the lava flows were 3.8 km long, and within 370 m of houses in El Patrocinio. Another flow front was 250 m E of El Rodeo, and obstructed the road that connects El Rodeo, El Caracol, and Los Pocitos.

Piton de la Fournaise – Reunion Island (France) : OVPF reported that a seismic crisis at Piton de la Fournaise began at 1457 on 9 April and was accompanied by rapid deformation beneath the S flank. Seismicity indicated that a fissure opened at 1900 but could not be visually confirmed due to weather conditions. The Alert Level was raised to 2-2. During an overflight at 0840 on 10 April scientists observed a NNW-oriented fissure, 700 m S of Château Fort. Activity was focused at two vents, each producing lava fountains that were no higher than 30 m tall, though fountains also rose from other parts of the fissure. Slow-moving ‘a’a lava flowed SE and then curved E and advanced 1.6 km to 1,800 elevation. The N end of the fissure was no longer active. Two cones had formed over the main vents and were growing larger; by 11 April the more northern vent was the larger of the two. Fountains rose 30-60 m and the lava flow had advanced to 1,750 m elevation. By 1900 on 11 April the lava flow was 3.2 km long and had reached 1,690 m elevation. Lava fountaining continued at the two vents during 12-13 April, rising 20-60 m. The lava flow continued to advance; by 13 April the flow was about 3.6 km long and had reached 1,500-1,550 m elevation.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that low-level ash emissions from Semisopochnoi were visible in satellite images on 12 April along with a steam plume drifting E beyond the island. Additionally, new ash deposits extending SE at least to the coastline were also visible. The event was recorded by the regional infrasound network. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Soufriere St. Vincent – St. Vincent : University of the West Indies Seismic Research Centre (UWI-SRC) and National Emergency Management Organisation (NEMO) reported that the effusive eruption at Soufrière St. Vincent (often simply referred to as “La Soufriere”) became explosive on 9 April after a period of increased seismicity, gas emission, and rapid dome growth. Earthquake swarms were recorded during 22-25 March and 5 April, signifying a change in the eruption pattern. Small earthquakes associated with dome growth were recorded on 7 April. Episodes of tremor indicating movement of magma and fluids close to the surface began at 0300 on 8 April and were again recorded at 0530, 0800, 1015, and 1300, slowly increasing in magnitude. Five long-period earthquakes and two brief swarms of VT events occurred in between the tremor episodes; ash venting occurred with the last episode. Sulfur dioxide emissions were identified in satellite data, and clouds of steam and gas were visible from the Belmont Observatory. Later that evening, incandescent material over the vent area was visible in webcam images, and views from the observatory indicated that the dome had grown significantly. The Alert Level was raised to Red at around 1830, and the Prime Minister issued an evacuation order for the Red Zone at the N part of the island, affecting 16,000-20,000 people.

An explosive eruption began at 0840 on 9 April when an ash plume rose to 8 km (27,900 ft) a.s.l. and drifted mainly ENE. Ash fell across the island, affecting communities including Chateaubelair and Petite Bordel, the observatory, Belmont and surrounding areas at the S end of the island, and forcing the closure of the Argyle International Airport (20 km S). NEMO stated that evacuations in the Orange and Red zones were impeded by significant ashfall and poor visibility, but by the evening most residents had been evacuated. A second period of vigorous ash venting began at 1445 and initially rose about 4 km (13,100 ft) a.s.l. Lightning was visible in the rising plume. Successive explosions and ash pulses fed the plume for hours and it rose to 16 km (52,000 ft) a.s.l. A third explosive series began at 1835. Ash venting occurred through the night, causing ashfall across St. Vincent and reaching Barbados, about 165 km E, significantly impacting residents on that island.

Periods of banded tremor began at 0330 on 10 April, lasting for periods of 20-30 minutes with 1-3-hour gaps. The tremor episodes were associated with explosive activity and stronger pulses of ash emissions to higher altitudes; ash plumes rose to 10.6-16 km (35,000-52,000 ft) a.s.l. throughout the day. The Washington VAAC stated that ash plumes during 9-10 April had drifted as far as 1,200 km ESE and about 3,000 km ENE. The Grantley Adams International Airport (GAIA) in Barbados also closed.

Ashfall continued to be widespread on 10 April; deposit thickness varied from less than 1 mm in Colonaire (~12.5 km SSE) to 10-15 mm in Rabacca (~7.4 km SSE). Scientists reported darkness at the observatory at 1617; video showed intense and continuous ashfall. Satellite data confirmed that explosions had excavated the 2020-2021 lava dome and parts of the 1979 dome, leaving a large crater.

Overnight during 10-11 April ash again fell island-wide, and also in the Grenadines (to the SSW), Barbados, and Saint Lucia (50 km NNE). Explosions early on 11 April were followed by widespread power and water outages on the island as reported by NEMO, and some houses had collapsed under the significant ashfall. Beginning around midday the periods between episodes of high-amplitude tremor lengthened from 1.5-4 hours to 5-8 hours. The VAAC reported that through the day ash plumes rose 12.2-16 km (40,000-52,000 ft) a.s.l. and continued to drift long distances to the ENE, E, and SE. A large explosion at 0415 on 12 April produced an ash plume that rose to 12.8 km (42,000 ft) a.s.l. Pyroclastic flows descended several valleys on the S and W flanks, reaching the coast at Morne Ronde (4.3 km W), Larikai (3.5 km WNW), and Trois Loupes Bay (3.5 km NW). Damage to vegetation was extensive along the W coast, stretching from Larikai Bay to Turner Bay. The pattern of seismicity again changed; high-amplitude tremor episodes ceased, but two low-amplitude and one high-amplitude episode were recorded during 0600-1700. Explosivity or notable ash venting coincided with the episodes; the spacing between explosive events increased.

A series of Vulcanian explosions began at 0630 on 13 April and lasted about 30 minutes. The VAAC stated that a dense ash plume rose to 11 km (35,000 ft) a.s.l. and drifted E and SE, as well as N and NE. Pyroclastic flows traveled about 6 km WSW, reached the ocean at Wallibou Bay, and extended past the coastline over the sea. Scientists observed the western coastline later in the day and noted that pyroclastic flows had descended all valleys from Larikai (W) to Wallibou, a stretch about 5 km long. Lahar deposits were observed in the Sandy Bay area. The VAAC noted that at 1850 a new ash emission rose to 7.6 km (25,000 ft) a.s.l. and was associated with a thermal anomaly. UWI-SRC stated that a large explosion was recorded around 2300. Pyroclastic flows overnight were channeled to the E into the Rabacca River drainage. The Montserrat Volcano Observatory stated that a sulfur odor and minor ashfall from Soufrière St. Vincent was observed on their island (390 km NNW).

Daily satellite-based measurements of SO2 were notable beginning on 9 April. Though the initial explosion at 0840 showed relatively minor SO2 emissions, stronger, continuous ash and SO2 emissions began later on 9 April (at 1445) and continued into the next day, transitioning into discrete explosive events that continued a least through 14 April. Satellite data showed about 0.4 teragrams (Tg) of SO2 in the plume on 10 April, with some stratospheric injection. Simon Carn noted that this makes the La Soufriere eruption the largest tropical SO2 emission since the 2011 Nabro eruption, and the largest in the Caribbean since satellite measurements began in 1979. The SO2 plume initially fanned out to the NE, E, and SE across the Atlantic Ocean. Measurements during 11-13 April showed similar results of 0.4-0.6 Tg SO2 depending on altitude. The eastern edge of the gas plume reached about 4,700 km to the W coast of Africa by 12 April, and another 2,000 km inland to Mali and Niger on 13 April.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that incandescence from Suwanosejima’s Ontake Crater was visible at night during 5-9 April. Four explosions generated ash plumes that rose as high as 1.6 km above the crater rim and ejected bombs 600 m away. Ashfall was reported in Toshima village (4 km SSW) during 8-9 April. The Alert Level remained at 2 and the public was warned to stay 1 km away from the crater.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 31 March 2021 – 6 April 2021

Aira – Kyushu (Japan) : JMA reported that during 29-30 March explosions at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) produced ash plumes that rose as high as 2.7 km above the crater rim and ejected bombs 600-900 m away. An explosion was recorded on 4 April. An explosion at 0641 on 5 April ejected bombs 800-1,100 m away from the crater and generated an ash plume that rose up to 3 km above the crater rim. The Alert Level remained at 3 (on a 5-level scale).

Dukono – Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that during 31 March-6 April ash plumes from Dukono rose to 2.4 km (8,000 ft) a.s.l. and drifted E, SE, and SSE. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Ebeko – Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 25 and 28-29 March that sent ash plumes up to 2.5 km a.s.l. (8,200 ft) and drifted in different directions. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Etna – Sicily (Italy) : INGV reported continuing episodes of lava fountaining, intra-crater explosive activity, and discontinuous ash emissions at Etna’s Southeast Crater (SEC) during the week of 29 March-4 April, though weather conditions often prevented visual observations. Gas emissions rose from the other summit craters and occasional explosive activity was visible; puffs of ash sometimes rose from Voragine Crater during 31 March-2 April. At 0707 on 31 March a loud explosion was followed by several ash puffs, marking the beginning of the 17th lava-fountaining episode since they began on 16 February. At around 1100 a thermal anomaly at the S base of SEC was visible during an overflight and in thermal camera images. Explosive activity increased by late afternoon and several lava flows effused from the S-base vent. The main part of the flow traveled towards the Valle del Bove with other smaller flows traveled S and SW. Two other vents at the S base had opened by evening and one ejected spatter a few tens of meters high. Periods of lava fountaining began through the night, and the main lava flow descended the W wall of the Valle del Bove. Strombolian activity intensified at 1950, with an eruption plume that rose to 1.2 km (4,000 ft) a.s.l. and drifted SSW. Lava fountaining began at around 0100 on 1 April. At 0218 lava overflowed the E rim of SEC and headed towards the Valle del Bove, running parallel to the flows from the S base. Lava fountains continued to be visible during the morning of 1 April and intense Strombolian activity produced dense ash plumes that drifted S. By 0940 the eruption plume had risen to 9 km (29,500 ft) a.s.l. and drifted SSW. Lava fountaining ceased around 1000 and the eruption plume rose to 5.5 km (18,000 ft) a.s.l. and drifted S. Ash fell in Milia, Nicolosi, and Catania and lapilli (1 cm in diameter) fell in Rifugio Sapienza. Lava effusion and flow advancement continued; lava from the S base of SEC spread out like a fan. A series of loud bangs were audible in the late morning and ash emissions continued until the afternoon. Lava overflowed the E rim of SEC at 1040, and a SSE flow entered the Valle del Bove at the SW wall. Explosive activity began to decline at 1320, and effusive activity waned overnight during 1-2 April.

Gareloi – United States : AVO reported that a loss of operation and communication with all seismic stations on Gareloi was likely due to snow cover. Both the Aviation colour Code and the Volcano Alert Level were changed to Unassigned, reflecting the lack of this data to detect unrest. The observatory noted that regional infrasound networks, lightning detection, and satellite images will be used to monitor and detected unrest.

Kilauea – Hawaiian Islands (USA) : HVO reported that the W vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 31 March-6 April. Lava flowed at a low rate from the main vent into the lake through crusted-over channels and submerged inlets. The total depth of the lake measured about 225 m and lava continued to circulate in the W part; the E half of the lake remained solidified and expanded toward the W. The sulfur dioxide emission rate was 1,200 tons/day on 1 April. HVO field crews observed weak spattering from two areas at the W vent during 1-2 April. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Langila – New Britain (Papua New Guinea) : Based on analyses of satellite imagery and wind model data, the Darwin VAAC reported that on 5 April an ash plume from Langila rose to 1.5 km (5,000 ft) a.s.l. and drifted SW.

Lewotolok – Lembata Island (Indonesia) : PVMBG reported that the Strombolian eruption at Lewotolok continued during 30 March-6 April. Gray-and-white ash plumes rose as high as 700 m above the summit and drifted in multiple directions, though rainy weather conditions prevented visual observations during 2-3 and 5 April. Incandescent material was ejected 300-500 m above the summit and 500 m SE during 30-31 March; eruptive events were recorded by the seismic network on the other days but not visually confirmed. Rumbling was occasionally noted. According to news articles secondary lahars from Cyclone Seroja destroyed homes, and impacted as many as 300, in several villages to the SW; mud-and-debris flows and flooding severely impacted other parts of Indonesia and killed at least 70 people. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 4 km away from the summit crater.

Merapi – Central Java (Indonesia) : BPPTKG reported that the lava dome just below Merapi’s SW rim and the lava dome in the summit crater both continued to grow during 26 March-1 April. The SW rim lava-dome volume was an estimated 1,060,000 cubic meters on 1 April, with a growth rate of about 13,400 cubic meters per day, and continued to shed material down the flank. A total of 14 pyroclastic flows traveled a maximum of 1.8 km down the SW flank. Incandescent avalanches, recorded 158 times, traveled as far as 1.1 km down the SW flank. The summit lava dome had grown to 70 m tall and produced one incandescent avalanche. Minor ashfall was reported in Ngadirojo, Stabelan (4 km NW), Takeran, Tlogolele (5 km NW), Selo (3 km NNW), Pos Babadan (4 km NW), and Pasar Talun (12 km W). The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 5 km away from the summit.

Raung – Eastern Java (Indonesia) : PVMBG reported that daily gray-and-white ash plumes rose 50-500 m above Raung’s summit during 31 March-5 April and drifted N and S. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 28 March-2 April. On 3 April a plume of re-suspended ash rose to 2.5 km (8,200 ft) a.sl. and drifted 250 km ESE. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Shishaldin – Fox Islands (USA) AVO reinstated the Green Aviation colour Code and the Normal Volcano Alert Level for Shishaldin on 2 April, after several seismic stations again became operational following a months-long outage, thus improving the observatory’s monitoring capability.

Sinabung – Indonesia : PVMBG reported that the eruption at Sinabung continued during 31 March-6 April. Weather conditions sometimes prevented visual observations of the volcano, though daily white fumarolic plumes were visible rising as high as 500 m above the summit. Avalanches were detected daily by the seismic network and observed traveling 500-1,500 m down the E and SE flanks. An eruptive event produced a gray ash plume that rose 500 m above them summit on 1 April. Pyroclastic flows went as far as 1.5 km down the E and SE flanks. Ash plumes rose 0.7-2 km during 2-5 April and mainly drifted E and SE. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km in the SE sector and 4 km in the NE sector.

Soufriere St. Vincent – St. Vincent : University of the West Indies Seismic Research Centre (UWI-SRC) and National Emergency Management Organisation (NEMO) reported that the lava dome in Soufrière St. Vincent’s main crater continued to slowly grow during 31 March-6 April, expanding to the N and S. Gas-and-steam continued to rise from the top of the dome, as well as along the contact with the pre-existing 1979 dome. A swarm of volcano-tectonic (VT) earthquakes began at 0638 on 5 April. The number and frequency of the VTs increased until about 0830 and then stabilized. The rate declined at around 1400 and then significantly dropped at 1600, though small VT events continued to be detected through 1800. The events were located at depths of 6 km, slightly deeper than the swarm events recorded during 22-25 March, located at revised depths of 3-5 km. Several reports of felt events came from nearby communities, including Fancy and Chateaubelair. The largest event, a M 3.5, was recorded at 0920 and felt by local residents. The swarm was more intense than the previous one, with an average rate of about 50 earthquakes per hour compared with 1.5 per hour during 22-25 March. The Alert Level remained at Orange (the second highest level on a four-colour scale).

Tanaga – Andreanof Islands (USA) : AVO reported a loss of operation and communication with all but two seismic stations on Tanaga, likely caused by snow cover. Both the Aviation colour Code and the Volcano Alert Level were changed to Unassigned, reflecting the inability to locate earthquakes to detect unrest. Monitoring will continue with the remaining seismic stations, regional infrasound networks, lightning detection, and satellite images.

Tengger Caldera – Eastern Java (Indonesia) : PVMBG reported that during 30 March-5 April white steam-and-gas plumes rose 50-700 m above the summit of Tengger Caldera’s Bromo cone. The plumes were white to gray during 1-2 April. The Alert Level remained at 2 (on a scale of 1-4), and visitors were warned to stay outside of a 1-km radius of the crater.

Ubinas – Peru : Instituto Geofísico del Perú (IGP) reported that during 29 March-4 April there were 11 volcano-tectonic earthquakes at Ubinas with magnitudes less than 1.8, and a few seismic signals indicated emissions. Sporadic steam-and-gas plumes rose as high as 200 m above the crater rim. On 5 April the Alert Level was lowered to Green (the lowest level on a four-colour scale).

Volcanos

Roundup of Global Volcanic Activity – New Activity for the Week 31 March 2021 – 6 April 2021

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that explosions at 1130 on 3 April likely caused ash plumes to rise to 8.5 km (27,900 ft) a.s.l. above Karymsky and drift NE, based on satellite data. The Aviation colour Code was raised to Orange (the second highest level on a four-colour scale).

Krysuvik-Trolladyngja – Iceland : IMO reported that the small eruption in the W part of the Krýsuvík-Trölladyngja volcanic system, close to Fagradalsfjall on the Reykjanes Peninsula, continued during 31 March-6 April. Video and visitor photographs showed spattering and lava fountaining from the two cones, and lava flows from both cones moved W and S within the Geldingadalur valley. A new fissure, 100-200 m long, opened about 700 m NE of the Geldingadalur cones around noon on 5 April. During a helicopter overflight, scientists observed a gas plume rising from the new fissure and a fast-moving lava flow descending into the Meradalir valley to the SE. On 6 April lava from the second fissure was advancing at a rate of 7 cubic meters per second; lava-flow rates at the Geldingadalir site averaged 5.5 cubic meters per second. Around midnight during 6-7 April a third fissure opened in between the first two; all three were oriented NE-SW. Earlier on 6 April field teams had observed a landslide in same area. Lava from the third fissure mostly flowed SW into Geldingadalur. The Aviation colour Code remained Orange due to the lack of ash and tephra emissions.

Pacaya – Guatemala : INSIVUMEH reported that explosions at Pacaya’s Mackenney Crater during 30-31 March produced gas-and-ash plumes that rose 1.8 km above the summit and drifted up to 50 km S, SW, W, and NW. Explosions ejected blocks as high as 150 m above the summit. Lava flows on the W flank advanced to 3 km long and were near La Breña; the flows overtook an unoccupied building on the Campo Alegre farm that was used for monitoring and visitor services. The flow front was about 500 m from the town of El Patrocinio. Incandescent blocks detached from the end of the lava flow and set fire to vegetation. During 31 March-2 April explosions ejected incandescent blocks as high as 225 m above the summit. Ash plumes rose 500 m and drifted 20 km S and SW. The SW-flank lava flows remained active. Explosions continued during 3-6 April, with ash plumes rising as high as 1 km and drifting 6-20 km W, SW, and S. The lava flow continued to be active on the SW flank, setting fire to local vegetation. Strombolian activity ejected material 300 m high during 5-6 April.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that a small plume from Semisopochnoi’s North Cerberus crater was visible in a satellite image on 31 March. Steam obscured the crater during the first part of 1 April. Later that day an ash plume was visible, and was followed by a sulfur dioxide plume an hour later. At 2200 a plume rose to an altitude below 3 km (10,000 ft) a.s.l. No activity was identified in partly cloudy images during 2-6 April. The Aviation colour Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that during 30-31 March large volcanic bombs were ejected at least 41 times from Suwanosejima’s Ontake Crater as high as 800 m above the crater rim and to distances as far as 1 km. The Alert Level was raised to 3 (on a 5-level scale) at 0330 on 31 March and the public was warned to stay outside a 2 km radius of the crater. The increased activity prompted an overflight that same day where scientists confirmed several hundred high-temperature bomb deposits with a thermal camera within a 1 km radius. Explosions at 2205 on 30 March and 0257 on 31 March ejected bombs onto the S and SE flanks, respectively. Grayish-white emissions rose from the crater. After 1500 eruption plumes rose as high as 1.4 km above the crater rim. The number of explosions decreased; two per day were recorded during 1-2 April and one was recorded on 3 April. The Alert Level was lowered to 2 on 5 April and the public was warned to stay 1 km away from the crater.

Veniaminof – United States : AVO reported that during 31 March-1 April clear satellite and web camera images of Veniaminof showed no signs of emissions. On 2 April the Volcano Alert Level was lowered to Advisory and the Aviation colour Code was lowered to Yellow. Satellite data showed elevated surface temperatures, especially over the flank-vent lava flows through 4 April. Low-level ash emissions were recorded by the webcam on 5 April, prompting AVO to raise the Volcano Alert Level and Aviation colour Code to Watch and Orange, respectively. Tephra deposits were visible to the SE.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 24 March 2021 – 30 March 2021

Aira – Kyushu (Japan) : JMA reported that during 22-26 March incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible nightly. An explosion on 25 March produced an eruption plume that rose 1.4 km above the crater rim. On 27 March at 0236 an eruption generated an ash plume that rose 2.5-4 km above the crater rim and drifted NW, resulting in a large amount of ashfall in Kagoshima City (about 10 km W). Volcanic bombs were ejected 1-1.3 km away from the crater. An eruption on 29 March at 1557 produced an eruption plume that rose 2.2 km above the crater rim and drifted SE, resulting in a pyroclastic flow down the SE flank and ashfall in Kagoshima City and the Kagoshima Prefecture. An explosion on 30 March at 0433 generated an ash plume that rose 2.7 km above the crater and drifted E, ejecting bombs 600-900 m from the crater. Ashfall was again reported in Kagoshima City. The Alert Level remained at 3 (on a 5-level scale).

Dukono – Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that during 24-30 March ash plumes from Dukono rose to 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Ebeko – Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 19, 21, and 24-25 March that sent ash plumes up to 2.5 km a.s.l. (8,200 ft) and drifted in different directions. Ashfall was reported in Severo-Kurilsk on 24 March. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego – Guatemala : INSIVUMEH reported that 6-11 explosions per hour were recorded during 24-30 March at Fuego, generating ash plumes that rose to 4.7 km (15,000 ft) a.s.l. and drifted W, NW, and SW as far as 10-15 km. Shock waves rattled buildings near the volcano. Block avalanches descended the Seca (W), Ceniza (SSW), and Trinidad (S) drainages, often reaching vegetated areas. Ash plumes from explosions rose to 4.8 (16,000 ft) km a.s.l. and drifted N and NE on 25 March and W on 27 March far as 15-20 km, resulting in ashfall in Morelia (9 km SW), Panimache (8 km SW), Yucales (12 km SW), Sangre de Cristo (8 km WSW), Yepocapa (8 km NW), La Soledad (11 km N). Block avalanches descended the Taniluyá (SW), Las Lajas (SE), and Honda drainages, in addition to those affected on 24 March. Weak crater incandescence was observed at night and in the early morning during 26 March. Incandescent material was ejected 100-200 m above the summit on 28 March, accompanied by ash plumes that rose to 4.8 km a.s.l. and resulted in ashfall in Palo Verde, Panimaché II, Sangre de Cristo, Yepocapa, and El Porvenir (8 km ENE).

Ibu – Halmahera (Indonesia) : PVMBG reported that on 25 March at 1814 a gray ash plume from Ibu rose to 2.3 km (7,500 ft) a.s.l. and drifted W. White-and-gray emissions rose 200-1,000 m above the crater drifting N, S, E, and W during 25-26, 28, and 30 March. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater and 3.5 km away on the N side.

Kilauea – Hawaiian Islands (USA) : HVO reported that the W vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 24-30 March. Lava flowed from the main vent into the lake through two crusted-over channels and submerged inlets, the former of which occurred during 24-25 March. The total depth of the lake measured about 224 m and lava continued to circulate in the W part; the E half of the lake remained solidified, expanding toward the W. The sulfur dioxide emission rate was 950 and 650 tons/day on 22 and 26 March, respectively. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Klyuchevskoy – Central Kamchatka (Russia) : KVERT reported that the flank eruption on Klyuchevskoy’s lower NW flank had ended on 20 March. Weak incandescence from the cinder cone and lava flows visible in webcam images reflected cooling. The temperature of the thermal anomaly identified in satellite data continued to decrease. On 24 March the Aviation colour Code was lowered to Green (the lowest level). According to satellite data, a plume of resuspended ash extended for 72 km E of the volcano on 25 March; no eruption was reported. On 25 March the Aviation colour Code was briefly increased to Orange (the second highest level on a four-colour scale) and was lowered to Green by 26 March.

Lewotolok – Lembata Island (Indonesia) : PVMBG reported that the Strombolian eruption at Lewotolok continued during 24-30 March. Daily gray-and-white ash plumes rose as high as 800 m above the summit and drifted in different directions. Incandescent material was ejected 500 m above the summit on 23, 27, and 30 March, and 300 m above the summit on 25 March. On 26 and 28 March incandescence was observed up to 100 m above the summit, accompanied by incandescent ejecta as far as 350 m to the SE. The eruptive events were accompanied by rumbling and banging sounds. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 3 km away from the summit crater.

Merapi – Central Java (Indonesia) : BPPTKG reported that the lava dome just below Merapi’s SW rim continued to grow and shed material down the flank during 19-25 March. The 2021 lava dome volume was an estimated 949,000 cubic meters on 25 March, with a growth rate of about 13,300 cubic meters per day. The Mount Merapi Selo Observation Post reported a white gas-and-steam plume rose 500 m above the crater on 25 March at 1430. Four pyroclastic flows traveled a maximum of 1.8 km down the SW flank, three of which occurred on 27 March at 0602, 0603, and 0631. An ash plume caused by a pyroclastic flow rose 3.5 km (12,000 ft) a.s.l. and drifted SW for about 1.3 km on 27 March at 1758 on, according to a ground observer. Incandescent avalanches, recorded 104 times, traveled as far as 1.2 km down the SW flank and twice down the SE flank as far as 400 m. The summit lava dome measured 65 m tall, similar to the previous week. On 30 March there were 33 incandescent avalanches observed traveling up to 1 km down the SW flank, one of which continued up to 1.5 km. One incandescent avalanche was observed from the lava dome. The Alert Level remained at 3 (on a scale of 1-4), and the public were warned to stay 5 km away from the summit.

Raung – Eastern Java (Indonesia) : PVMBG reported that daily gray-and-white ash plumes rose 50-1,200 m above Raung’s summit during 24-29 March. Ash plumes drifted in different directions. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Reventador – Ecuador : IG reported that a high level of activity continued to be recorded at Reventador during 24-30 March; adverse weather conditions sometimes prevented visual confirmation. Seismicity was characterized by 49-80 daily explosions, volcano-tectonic and harmonic tremor events, and long-period earthquakes, as well as signals indicating emissions. Gas, steam, and ash plumes, often observed multiple times a day with the webcam or reported by the Washington VAAC, rose as high as 1.4 km above the summit crater and drifted mainly W, NW, SW. Crater incandescence and incandescent blocks rolling down the NE flank were observed nightly and accompanying explosions during 24-25 March.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported a daily average of 90 explosions at Sabancaya during 22-28 March. Gas-and-ash plumes rose as high as 2.5 km above the summit and drifted SW, W, N, and NW. Six thermal anomalies originating from the lava dome in the summit crater were identified in satellite data. Minor inflation continued to be detected in areas N of Hualca Hualca (4 km N). The Alert Level remained at Orange (the second highest level on a four-colour scale) and the public were warned to stay outside of a 12-km radius.

Sangay – Ecuador : IG reported a high level of activity at Sangay during 24-30 March. Seismicity was characterized by 1-8 daily explosions, long-period earthquakes, and signals indicating emissions. Weather clouds and rain often prevented visual observations of the volcano, though based on the Washington VAAC reports, daily ash plumes were noted rising as high as 2.1 km above the summit and drifting in different directions. Images shared by the Red de Observadores Volcánicos (ROVE) (Network of Volcanic Observers) showed gas-and-steam emissions reaching 900-1,000 m above the crater drifting N on 26-27 March. A seismic station recorded occasional debris flows during 24-30 March. No ashfall was reported by residents.

Santa Maria – Guatemala : INSIVUMEH reported that during 24-30 March weak explosions at Santa María’s Santiaguito lava-dome complex generate ash plumes that rose to 2.8-3.4 km (9,000 ft-11,000 ft) a.s.l. and drifted W, NE, SW. Collapses of blocky lava from the Caliente dome sent avalanches on the S and SW flank of the Caliente dome, causing minor ashfall around the volcano. Block avalanches were also observed on the E and S flanks; ashfall was reported in San Marcos (8 km SW) and Loma Linda Palajunoj (6 km WSW) on 25 and 27 March. Minor pyroclastic flows were reported on 28 March.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that lava dome growth at Sheveluch continued during 20-26 March, accompanied by strong fumarolic activity, incandescence, and block avalanches. Satellite imagery showed a thermal anomaly over the lava dome all week, except on 22 and 25 March due to cloud cover. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung – Indonesia : PVMBG reported that the eruption at Sinabung continued during 24-30 March. The Darwin VAAC reported that an eruption on 28 March generated an ash plume that rose to 3.4 km a.s.l. (11,000 ft). Explosions on 29 March at 0024 and 1035 produced ash plumes that rose to 3.5 km a.s.l. (11,500 ft) and drifted NNE and ESE, respectively. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km in the SE sector and 4 km in the NE sector.

Soufriere St. Vincent – St. Vincent : University of the West Indies Seismic Research Centre (UWI-SRC) and National Emergency Management Organisation (NEMO) reported that the lava dome in Soufrière St. Vincent’s main crater continued to slowly grow during 23-27 March, expanding to the N and S. Gas-and-steam continued to rise from the top of the dome, as well as along the contact with the pre-existing 1979 dome. On 23 March at 1030 the monitoring network recorded a swarm of small low-frequency seismic events that lasted about 45 minutes, which was likely associated with magma movement beneath the dome. Starting at 1653 the monitoring network also began to detect volcano-tectonic (VT) earthquakes, some of which have been felt by nearby communities, including Fancy, Owia, and Sandy Bay. On 26 March the period of elevated VT earthquakes stopped; only small, low frequency events associated with the growth of the lava dome were recorded. The Alert Level remained at Orange (the second highest level on a four-colour scale).

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the seismic network for Suwanosejima’s Ontake Crater detected a total of 17 explosions during 19-26 March. These events produced eruption plumes that rose as high as 1.2 km above the crater rim, drifting S, W, and SW, and ejected bombs as far as 500 m away from the crater. Incandescence from the crater was occasionally visible at night. On 30 March at least 18 explosions were detected, generating ash plumes that rose 600-1,500 m above the crater drifting E, SE, and NE and ejecting material as far as 800 m S of the crater. On 31 March the Alert Level was raised to 3 (on a 5-level scale).

Volcanos

Roundup of Global Volcanic Activity – New Activity for the Week 24 March 2021 – 30 March 2021

Cleveland – Chuginadak Island (USA) : AVO reported that a magnitude 4.3 earthquake at Cleveland was recorded during the morning of 26 March. Smaller earthquakes continued to be detected that day at a decreasing rate. There have been no signs of activity observed in infrasound or satellite data, nor evidence of volcanic gas emissions and elevated surface temperatures due to clouds. The Aviation colour Code remained at Yellow and the Volcano Alert Level remained at Advisory.

Etna – Sicily (Italy) : INGV reported continuing episodes of lava fountaining at Etna’s Southeast Crater (SEC) during the week of 22-28 March, though weather conditions often prevented visual observations. Weak Strombolian activity at SEC began at 2005 on 23 March and turned into lava fountaining at 0330 on 24 March. A lava flow from the SEC was observed at 0335 which split in two, one branch traveling toward the Valle del Bove and the other to the SE; the lava was followed by a pyroclastic flow at 0336 that traveled toward the Valle del Bove. The lava fountain produced an ash cloud that rose to 6-7 km (20,000-23,000 ft) a.s.l. and extended SSE, resulting in ashfall on the S slope and in Catania (29 km SSE). Lava fountaining gradually decreased at 0700, and by 0945 it had stopped. The lava flows continued to advance. Activity in Northeast (NEC), Bocca Nuova (BN), and Voragine (VOR) was characterized by variable intra-crater Strombolian activity, accompanied by sporadic and weak ash emissions that quickly dispersed. On 24 March explosions at SEC continued after the lava fountaining had stopped, producing an ash plume that rose 4.5 km (15,000 ft) a.s.l. and drifted SE. At night, ashfall was reported in Milia and Trecastagni (16 km SE). Explosions stopped by 1347 that day. By 25 March the two active lava flows had ceased and began to cool. Weak Strombolian activity at SEC on 30 March resumed around 2030; intra-crater explosions continued in the NEC, BN, and VOR, the latter of which produced discontinuous ash emissions that rapidly dispersed in the summit area.

Krysuvik-Trolladyngja – Iceland : IMO reported that the small eruption in the W part of the Krýsuvík-Trölladyngja volcanic system, close to Fagradalsfjall on the Reykjanes Peninsula continued during 24-30 March. Video and visitor photographs showed that continuous spattering and lava fountaining resulted in the formation of a second large cone adjacent to the main cone. Lava flows from both cones moved W and S within Geldingadalur valley. On 25 and 29 March the extrusion rate from the cone was an estimated 5.8 and 5.3 cubic meters per second, respectively, based on the latest Pléiades image acquisition (LMI). A gas plume on 25 and 29 March rose to 1 km (3,300 ft) a.s.l; no ash or tephra was produced. Minor seismicity continued around the Fagradalsfjall area. Video data showed that on the morning of 28 March the N part of the largest cone along the fissure collapsed. Sulfur dioxide flux was 18-19 kg/s and drifted predominantly S. The IMO periodically issued warnings about weather conditions that would cause high concentrations of volcanic gases to settle near the eruption site, causing hazardous conditions for visitors. The Aviation colour Code remained Orange due to the lack of ash and tephra emissions.

Pacaya – Guatemala : INSIVUMEH reported moderate to s trong explosions at Pacaya’s Mackenney Crater during 24-30 March, accompanied by abundant ash plumes that rose to 2.9-4.5 km (9,500-13,000 ft) a.s.l. and drifted in multiple directions as far as 15-20 km. Resulting ashfall was reported in El Pepinal (7 km N), San Francisco de Sales (5 km N), El Cedro (9 km NNW), Calderas (3 km N), Mesías Altas, Mesías Baja (5 km NE), El Rodeo (4 km WSW), El Patrocinio (5 km W), and San Vicente Pacaya (5 km NW). The lava flow that began on 18 March was 2.5 km long, continuing down the SW flank; the height of the flow was 2.5 m with a width of 400 m, but the advancing front was 250 wide and set fire to nearby vegetation. Incandescent material ejected 150-300 m above the rim fell around the crater on 25 and 27 March. On 30 March ash plumes drifted 7 km S, causing ashfall in El Chupadero (2-2.5 km S) and Los Pocitos (5.5 km S).

Pelee – Martinique (France) : L’Observatoire Volcanologique et Sismologique de Martinique (OVSM) reported that seismicity at Pelée increased during 19-26 March. The seismic network recorded at least 55 high-frequency volcano-tectonic earthquakes with magnitudes less than or equal to 1, located at depths between 1.7 km below sea level and 1 km above sea level. The Alert Level remained at Yellow (the second lowest level on a four-colour scale).

Piton de la Fournaise – Reunion Island (France) : OVPF reported that seismicity remained elevated at Piton de la Fournaise during 22-26 March. On 24 March there were 81 earthquakes recorded under the summit, accompanied by deformation and 31 collapses along the edges of the Dolomieu Crater. Inflation centered 1.5 and 2 km below the crater continued through the week. On 26 March up to 95 summit volcano-tectonic earthquakes were recorded; the daily number of earthquakes then decreased, with 55 on 27 March and 8 on 28 March.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that satellite data showed minor ash deposits on Semisopochnoi’s flanks. Three explosions on 25 March (at 0142, 0330, and 0645) were recorded by regional infrasound sensors. Two more explosions were detected at 2130 on 26 March and at 0030 on 27 March; high weather cloud cover at 9.1 km (30,000 ft) a.s.l. prevented satellite confirmation; no ash was visible above the cloud deck during 25-27 March. The Aviation colour Code and the Volcano Alert Level remained at Orange and Watch, respectively.

Taal – Luzon (Philippines) : PHIVOLCS reported that seismicity increased at Taal during 24-27 March. There were around 19-302 volcanic earthquakes recorded daily, except on 28 March, and about 4-243 periods of volcanic tremor with variable durations (1-24 minutes). Four hybrid earthquakes were recorded on 24 March. Low-frequency earthquakes were detected 25, 77, 118, 7, and 16 times on 25, 26, 27, 28, and 30 March, respectively. Diffuse steam plumes from fumarolic vents in the Main Crater rose as high as 40 m. Daily measurements of sulfur dioxide emissions were 837-1,109 tonnes/day. The Alert Level for Taal remained at 2 (on a scale of 0-5). PHIVOLCS strongly recommended no entry onto the island, and access to the Main Crater and Daang Kastila fissure (along the walking trail) was strictly prohibited.

Veniaminof – United States : AVO reported that eruptive activity at Veniaminof continued during 24-25 and 27-30 March. Highly elevated surface temperatures were visible in satellite images along with ash deposits that were primarily confined to the summit and upper flanks on 23 March. Low-level tremor was recorded in local seismic data. During 24 March explosions were recorded in local seismic data and in infrasound data sensors; frequent explosive booming (several per minute) was reported by residents in Perryville (35 km SE) and Chignik Lagoon (55 km NE). Cloud cover prevented visual confirmation during this period of increased seismicity. Fresh ash deposits extending 10 km SE in the summit caldera were observed in satellite data on 25 March. Satellite data also showed highly elevated surface temperatures at the summit and flank vent during clear weather days on 25, 28, and 29 March. Discrete, short-lived ash emissions were detected during the afternoon and evening of 27 March in images from the FAA webcam in Perryville. The intermittent events lasted several minutes and produced small ash clouds that rose less than 300 m (1,000 ft) above the vent and drifted SE, which may have resulted in trace ashfall in Perryville, though there was no confirmed evidence. The Volcano Alert Level remained at Watch and the Aviation colour Code remained at Orange.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 17 March 2021 – 23 March 2021

Aira – Kyushu (Japan) : JMA reported that during 15-22 March incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible nightly. An explosion on 15 March produced an eruption plume that rose 1.5 km above the crater rim and ejected bombs 500-700 m away from the crater. The explosions on 20 March generated plumes that rose as high as 1.6 km. The sulfur dioxide emission rate was 1,800 tons per day on 12 March. The Alert Level remained at 3 (on a 5-level scale).

Dukono – Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that during 16-23 March ash plumes from Dukono rose to 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Ebeko – Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 12-15 and 18-19 March that sent ash plumes to 2.6 km (8,500 ft) a.s.l. and drifted E, NE, and NW. Ashfall was reported in Severo-Kurilsk on 12 March. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kilauea – Hawaiian Islands (USA) : HVO reported that two vents on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 17-23 March. Lava flowed from both the main vent and a vent several meters NE into the lake through submerged inlets. Another lava flow emerged from about halfway up the cone structure starting at 0220 on 16 March, but had ended by the next day. The depth of the western part of the lake rose from about 221 m to 223 m and lava continued to circulate in that part. The E half of the lake remained solidified and lower that the W half, with the crusted E half expanding towards the W. The sulfur dioxide emission rate was 650, 700, and 1,100 tons/day on 17, 18, and 19 March, respectively. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Klyuchevskoy – Central Kamchatka (Russia) : KVERT reported that the Strombolian eruption from vents on Klyuchevskoy’s lower NW flank continued during 12-19 March. A large, bright thermal anomaly over the vents was identified in satellite images. Kamchatka Volcanological Station scientists visited the eruption site on 16 March and observed decreased activity. A small lava flow effused from a vent at the W base of the cone and lava flowed from the N side. Every few seconds material was ejected as high as 100 m above the cone’s rim. On 22 March the cinder cone was weakly incandescent and lava effusion continued to be observed in webcam images. The temperature of the thermal anomaly identified in satellite data also significantly decreased. The Aviation colour Code was lowered to Yellow (the second lowest level on a four-colour scale) on 22 March. Two days later, on 24 March, the Aviation colour Code was lowered to Green (the lowest level); weak incandescence from the cone and flows visible in webcam images reflected cooling.

Laguna del Maule – Central Chile-Argentina border : SERNAGEOMIN reported that during 1-15 March the seismic network at Laguna del Maule recorded a total of 123 volcano-tectonic earthquakes. The largest event was a local M 2.4 located 8.2 km WSW of the lake, at a depth of 4.4 km. One tremor event was also recorded. Recent carbon dioxide emission measurements showed an upward trend and that the area of anomalous emissions had expanded. Deformation rates were higher than maximum averages. The Alert Level remained at Yellow, the second lowest level on a four-colour scale. ONEMI maintained a Yellow Alert for San Clemente and recommended restricted access within a radius of 2 km from the center of elevated carbon dioxide emissions.

Lewotolok – Lembata Island (Indonesia) : PVMBG reported that the Strombolian eruption at Lewotolok continued during 17-23 March. Daily gray-and-white ash plumes rose as high as 700 m above the summit and drifted mainly E and SE. Incandescent material was ejected 300 m E of the summit on 20 March. The next day incandescent material was ejected 100 m above the summit and as far as 200 m E. On 22 March explosions ejected incandescent material 250-350 m SE. The eruptive events were accompanied by rumbling and banging sounds. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 4 km away from the summit crater.

Nevados de Chillan – Chile : SERNAGEOMIN reported that activity at Nevados de Chillán’s Nicanor Crater was ongoing with sporadic gas-and-ash emissions and continuing lava effusion during 1-15 March. Explosions produced eruption plumes that rose as high as 1.3 km above the crater rim, and sometimes ejected material as far as 160 m onto the NE flank. The L5 lava flow on the N flank was about 925 m long and 80 m wide at the distal end, and continued to slowly advance. The Alert Level remained at Yellow, the second lowest level on a four-colour scale. ONEMI stated that Alert Level Yellow (the middle level on a three-colour scale) remained in place for the communities of Pinto and Coihueco, noting that the public should stay at least 2 km away from the crater.

Raung – Eastern Java (Indonesia) : PVMBG reported that daily gray-and-white ash plumes rose 300-900 m above Raung’s summit during 16-23 March. Ash plumes drifted mainly N, E, and S. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Reventador – Ecuador : IG reported that a high level of activity continued to be recorded at Reventador during 16-23 March; adverse weather conditions sometimes prevented visual confirmation. Seismicity was characterized by 31-81 daily explosions, volcano-tectonic and harmonic tremor events, and long-period earthquakes as well as signals indicating emissions. Gas, steam, and ash plumes were often observed multiple times a day with the webcam or reported by the Washington VAAC; they rose as high as 1.5 km above the summit crater and drifted mainly NE, E, and SW. Crater incandescence and incandescent blocks rolling at least down the N, NE, and E flanks were observed nightly.

Sangay – Ecuador : IG reported a high level of activity at Sangay during 17-23 March. Seismicity was characterized by daily explosions, long-period earthquakes, and signals indicating emissions. Weather clouds and rain often prevented visual observations of the volcano, though based on the Washington VAAC, webcam images, and observer reports, ash plumes were noted most days rising as high as 1.5 km above the summit and drifting mainly N, W, and SW. A seismic station recorded occasional debris flows during 17-19 March. No ashfall was reported by residents.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 12-19 March. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung – Indonesia : PVMBG reported that the eruption at Sinabung continued during 16-23 March. Weather conditions often prevented visual observations of the volcano, particularly during the end of the week. Avalanches were detected daily by the seismic network and observed traveling 500-1,500 m down the E and SE flanks during 16-18 March. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km in the SE sector and 4 km in the NE sector.

Soufriere St. Vincent – St. Vincent : University of the West Indies Seismic Research Centre (UWI-SRC) and National Emergency Management Organisation (NEMO) reported that the lava dome in Soufrière St. Vincent’s main crater continued to slowly grow during 17-23 March, expanding to the N and S. A team visited the dome on 19 and 23 March to make observations, take measurements, and maintain monitoring equipment. Gas-and-steam continued to rise from the top of the dome as well as along the contact between the old and new domes. As of 19 March the dome was 105 m tall, 912 m long, 243 m wide, and had an estimated volume of 13.13 million cubic meters. The Alert Level remained at Orange (the second highest level on a four-colour scale).

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the seismic network for Suwanosejima’s Ontake Crater detected a total of 11 explosions during 12-19 March. These events produced eruption plumes that rose as high as 1.7 km above the crater rim and ejected bombs up to 700 m away from the crater. Incandescence from the crater was occasionally visible at night. The Alert Level remained at 2 (on a 5-level scale).

Volcanos

Roundup of Global Volcanic Activity – New Activity for the Week 17 March 2021 – 23 March 2021

Cleveland – Chuginadak Island (USA) : AVO reported that on 10 March an earthquake at Cleveland was large enough to be recorded by seismometers 100 km away on Umnak Island. On 17 March volcanic gas emissions increased and elevated surface temperatures were identified in satellite images. The Aviation colour Code was raised to Yellow and the Volcano Alert Level was raised to Advisory.

Etna – Sicily (Italy) : INGV reported continuing episodes of lava fountaining at Etna’s Southeast Crater (SEC) on 15, 17, and 19 March, though weather conditions often prevented visual observations. Strombolian activity at SEC began at 2110 on 14 March and turned into lava fountaining at 0048 on 15 March. Lava traveled towards the Valle de Bove and an eruption plume drifted E. Lava fountaining ceased by 0343 and only weak Strombolian activity followed. The lava flows continued to advance. Weak Strombolian activity at SEC on 17 March began to intensify at 0155 and changed into lava fountaining at 0319. An eruption plume drifted SE and lava flow advanced. Fountaining activity ceased at 0717 and was followed by explosive activity. By 1859 the lava flows had reached 2,200 m elevation. Explosions at SEC and the lava flow in the Valle de Bove were visible at 2142 on 18 March when the weather conditions allowed for partial visibility of the summit. Explosive activity at SEC was visible at 0734 on 19 March. The activity intensified at 0915 and ash emissions were visible. Lava fountaining started at 0935 and an ash plume drifted ENE. Lava fountaining activity ceased at 1136 and changed to Strombolian activity which gradually decreased; by 1350 only sporadic explosions were visible along with minor ash emissions. Lava flows were noted late in the morning.

Krysuvik-Trolladyngja – Iceland : IMO reported that a small eruption in the western part of the Krýsuvík-Trölladyngja volcanic system, close to Fagradalsfjall on the Reykjanes Peninsula, began at around 2045 on 19 March. The eruption was first visible in webcam images and confirmed by satellite data, and an orange glow in clouds on the horizon was seen from Reykjanesbaer and Grindavík (10 km SW). The Aviation colour Code was raised to Red. Reykjanesbraut, the main road from the capital region to Reykjanesbaer and the international airport at Keflavík, was closed. A fissure, 500-700 m long, had opened on a slope in the Geldingadalur valley about 4.7 km N of the coast and just off the SE flank of Fagradalsfjall mountain. Small lava fountains rose as high as 100 m above the fissure, and by 1110 on 20 March, the lava had covered an area less than 1 square kilometer and was approximately 500 m across. The extrusion rate was an estimated 5 cubic meters per second. The Aviation colour Code was lowered to Orange because there was little to no ash production that would affect aircraft. Reykjanesbraut reopened, but Sudurstrandarvegur, the road along the S coastline, was closed between Grindavík and Thorlakshofn. The eruption continued during 21-23 March with a consistent extrusion rate. About three cones had formed along the fissure; the tallest and widest was situated at the higher part of the fissure. Lava flows, mainly from the largest cone, fanned out to the NW, W, and SW, and also flowed S and fanned out to the E. Spatter was ejected above the cones. Video captured by visitors showed parts of the largest cone collapsing and rebuilding. The IMO periodically issued warnings about weather conditions that would cause high concentrations of volcanic gases to settle near the eruption site, causing hazardous conditions for visitors. IMO noted that through the night of 22-23 March night sulfur dioxide levels in Reykjavík had increased, though not to unsafe levels.

Pacaya – Guatemala : INSIVUMEH reported periods of intense activity at Pacaya’s Mackenney Crater during 17-18 March. Explosions produced dense ash plumes that rose 500-1,000 m above the crater rim and drifted 25-30 km S, SW, W, NW, and N. Incandescent material was ejected 300-500 m above the crater and fell within a 600 m radius of the crater. Lava flows on the S flank were 1.5 km long and set fire to vegetation at the advancing edge. Two new lava flows were visible; one traveled 400 m E and the other traveled 500 m S. Ashfall was reported in El Rodeo (4 km WSW), Patrocinio (about 5 km W), El Cedro (9 km NNW), San Francisco de Sales (5 km N), Amatitlán (12 km N), and Villa Nueva (16 km N). Strong explosions during 21-23 March generated dense ash plumes that rose as high as 1.5 km above the summit. The plumes drifted 25-30 km NE, E, SE, and S, causing ashfall in Los Llanos, Los Pocitos (5 km S), Los Dolores (6 km SE), El Rodeo, Patrocinio, Mesías Alta and Mesías Baja, and Santa Elena Barillas (6 km ENE). Incandescent material was ejected 500 m above the crater and fell within 300-600 m of the crater. A lava flow on the SW flank was 1.5 km long, a flow on the S flank was 300 m long, and the E-flank lava flow had lengthened to 500 m. On 23 March ash plumes drifted 50 km NW, N, and NE, causing ashfall in Pepinal San Francisco de Sales, Los Pocitos, Los Dolores, Mesías Altas and Mesías Bajas, Santa Elena Barillas, Villa Nueva, and in the capital of Guatemala City (25-30 km NNE). Ash fell at Guatemala’s international airport, Aeropuerto Internacional La Aurora, 50 km N of Pacaya, causing the airport to close. Soldiers swept ash off of the runway and incoming flights were diverted to El Salvador.

San Cristobal – Nicaragua : The Washington VAAC reported that on 19 March a notable ash cloud from San Cristóbal rose at least to 12.2 km (40,500 ft) a.s.l. and drifted over 80 km ENE based on satellite data, ash dispersion models, and weather models.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that satellite data showed minor ash deposits on Semisopochnoi’s flanks and a possible gas cloud on 14 March. Two small explosions on 19 March, at 0350 and 0534, were recorded by regional infrasound sensors and prompted AVO to raise the Aviation colour Code and the Volcano Alert Level to Orange and Watch, respectively. A small explosion at 0230 on 21 March was followed by a series of smaller explosions. A volcanic gas cloud was visible in satellite data during the previous day. Three small explosions were detected during 22-23 March, though high weather cloud cover, at 9.1 km (30,000 ft) a.s.l., prevented satellite confirmation; no ash was visible above the cloud deck.

Taal – Luzon (Philippines) : PHIVOLCS reported that at Taal during 16-23 March there were 36-193 daily volcanic earthquakes and 27-156 daily periods of volcanic tremor with variable durations (1-15 minutes). Three hybrid earthquakes were recorded each day on 18 and 19 March. Diffuse steam plumes from fumarolic vents in Main Crater rose as high as 100 m. Daily measurements of sulfur dioxide emissions were 603-1,184 tonnes per day. The Alert Level remained at 2 (on a scale of 0-5). PHIVOLCS strongly recommended no entry onto the island, and access to the Main Crater and Daang Kastila fissure (along the walking trail) was strictly prohibited.

Veniaminof – United States : AVO reported that the eruption at Veniaminof continued during 17-23 March. Low surface temperatures were visible in satellite images along with steam-and-gas plumes. Low-level tremor was recorded in local seismic data. During the morning of 21 March small explosions were identified using seismic data and infrasound sensors in Chignik Lagoon. A volcanic gas cloud drifted SE at or below 1.5 km (5,000 ft) a.s.l. Small explosions were detected again during 21-23 March. Sulfur dioxide plumes were identified in satellite data. Minor ash emissions rose hundreds of meters and rapidly dissipated, though on 23 March a pilot saw an ash plume rise to 3 km (10,000 ft) a.s.l. Satellite data during 22-23 March showed highly elevated surface temperatures and subsidence of the glacial ice over the flank vent where lava was erupting. The Volcano Alert Level remained at Watch and the Aviation colour Code remained at Orange.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 10 March 2021 – 16 March 2021

Aira – Kyushu (Japan) : JMA reported that during 8-15 March incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible nightly. Seven explosions and 10 non-explosive events generated eruption plumes that rose 2.4-2.7 km above the crater rim and ejected bombs 0.8-1.7 km away from the crater. The sulfur dioxide emission rate was 2,300 tons per day on 10 March. The Alert Level remained at 3 (on a 5-level scale).

Dukono – Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that during 10-16 March ash plumes from Dukono rose to 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Ebeko – Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 5, 7-9, and 11-12 March that sent ash plumes to 2.3 km (7,500 ft) a.s.l. and drifted NE and E. Ashfall was reported in Severo-Kurilsk during 7-8 March. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kadovar – Papua New Guinea : Based on satellite and wind model data, the Darwin VAAC reported that on 11 March ash plumes from Kadovar rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted W.

Kilauea – Hawaiian Islands (USA) : HVO reported that vents on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 10-16 March. Lava flowed from both the main vent and a newer vent several meters NE into the lake through submerged inlets. Another lava flow emerged from about halfway up the cone structure starting at 0220 on 16 March. The depth of the western part of the lake rose from 221 m to 222 m and lava continued to circulate in that part. The E half of the lake remained solidified and lower that the W half, with the crusted E half expanding towards the W. The sulfur dioxide emission rate was 900 tons/day on 14 March. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Klyuchevskoy – Central Kamchatka (Russia) : KVERT reported that the Strombolian eruption from vents on Klyuchevskoy’s lower NW flank continued during 5-12 March. A large, bright thermal anomaly over the vents was identified daily in satellite images. A plume of re-suspended ash drifted 375 km E on 5 March. IVS FEB RAS posted that the lava traveled downslope, melting ice and snow on the Erman glacier; the meltwater formed mud flows along the along the Krutenkaya River. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Lewotolok – Lembata Island (Indonesia) : PVMBG reported that the Strombolian eruption at Lewotolok continued during 10-16 March. Daily gray-and-white ash plumes rose as high as 1.5 km above the summit and drifted mainly E and SE. The eruptive events were accompanied by rumbling and banging sounds. Visual observations were hindered by weather on 10 March; each day during 11-16 March incandescent material was ejected as high as 500 m above the crater. Almost daily incandescent material was ejected 500-1,300 m E and SE from the crater. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 4 km away from the summer crater.

Merapi – Central Java (Indonesia) : BPPTKG reported that the 2021 lava dome just below Merapi’s SW rim and the lava dome in the summit crater both continued to grow during 5-11 March. The 2021 lava-dome volume was an estimated 785,600 cubic meters on 11 March, with a growth rate of about 13,500 cubic meters per day, and continued to shed material down the flank. A total of 12 pyroclastic flows traveled a maximum of 1.9 km down the SW flank. Incandescent avalanches, recorded 226 times, traveled as far as 1.3 km down the SW flank. The height of the summit lava dome was relatively steady at 45 m. The Alert Level remained at 3 (on a scale of 1-4), and the public were warned to stay 5 km away from the summit.

Popocatepetl – Mexico : During an overflight of Popocatépetl on 5 March scientists from Instituto de Geofísica de la Universidad Nacional Autónoma de México (UNAM) and CENAPRED observed that the inner crater was 360-390 m in diameter and 150-182 m deep. Tephra deposits on the crater floor were visible and there was no sign of a lava dome. Each day during 10-15 March there were 35-104 steam, gas, and ash emissions that drifted mainly SSW and NW. Minor ashfall was reported in the municipalities of Amecameca (20 km NW) and Tlalmanalco (30 km NW) around 2250 on 12 March. An explosion was recorded at 2351 on 13 March. Minor ashfall was reported in Amecameca the next day. The Alert Level remained at Yellow, Phase Two (middle level on a three-colour scale).

Raung – Eastern Java (Indonesia) : PVMBG reported that daily gray ash plumes rose 100-1,200 m above Raung’s summit during 10-16 March. Ash plumes drifted mainly N, NE, E, and S. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Sangay – Ecuador : IG reported a high level of activity at Sangay during 10-16 March. Seismicity was characterized by daily explosions, long-period earthquakes, and signals indicating emissions. Weather clouds often prevented visual observations of the volcano, but satellite and webcam images recorded daily ash plumes. Ash plumes were notable during 10-11 March and impacted communities downwind with ashfall. Pyroclastic flows, visible in webcam images, descended the flanks at 0950 on 10 March. The Washington VAAC stated that ash plumes rose 6.7-8.5 km (22,000-28,000 ft) a.s.l. and drifted W at lower altitudes and NW at higher altitudes. A period of explosions recorded during 0315-0545 on 11 March produced ash plumes that rose as high as 13.7 km (45,000 ft) a.s.l., or 8.5 km above the summit, and drifted NW, W, and SW. Ash plumes drifted N, NW, and W, causing significant ashfall in Guamote (42 km WNW), notable ashfall in Chambo (43 km NW), Riobamba (50 km NW), Penipe (55 km NW), and Guano (55 km NW), and minor ashfall in Colta (55 km NW), Alausí (60 km SW), and Macas. According to a social media video post the ash plumes caused widespread darkness in Riobamba for several hours. Other residents posted photos of crops covered in ash. The eruption released 31 kilotons of sulfur dioxide, the highest value recorded during the current eruptive period that began in May 2019. Heavy rainfall overnight during 11-12 March caused hot lahars in the Volcán River drainage that reached the confluence of the Upano River. Overflows in the Upano River resulting in additional lahars and debris flows. Weather clouds hindered visual observations. During 13-15 March gas-and-ash plumes rose as high has 2 km above the summit and drifted NE. Seismic signals indicating lahars were recorded on 14 March. The VAAC reported that ash plumes rose to 6-9 km (20,000-30,000 ft) a.s.l. and drifted W and WNW on 16 March.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 5-12 March. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung – Indonesia : PVMBG reported that the eruption at Sinabung continued during 10-16 March. Avalanches of material traveled 500-1,500 m down the E, SE, and S flanks almost daily. Pyroclastic flows traveled 2-3 km down the E and SE flanks on 11 March. Ash plumes rose to 2.4-4.3 km (8,000-14,000 ft) a.s.l. and drifted SE, SW, and W during 10-12 and 15 March. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km in the SE sector and 4 km in the NE sector.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the seismic network for Suwanosejima’s Ontake Crater detected a total of 29 explosions during 5-12 March, less than the 131 explosions recorded previous week. These events produced eruption plumes that rose as high as 1.5 km above the crater rim. Incandescence from the crater was occasionally visible at night. Rumbling was heard in a village 4 km SSW. The Alert Level remained at 2 (on a 5-level scale).

Volcanos

Roundup of Global Volcanic Activity – New Activity for the Week 10 March 2021 – 16 March 2021

Bagana – Bougainville (Papua New Guinea) : Based on satellite and wind model data, the Darwin VAAC reported that on 10 March ash plumes from Bagana rose to 2.4 km (8,000 ft) a.s.l. and drifted NW and WNW.

Etna – Sicily (Italy) : INGV reported continuing episodes of lava fountaining at Etna’s Southeast Crater (SEC) on 9 and 12 March. The eleventh episode began with Strombolian activity at SEC observed at 1914 on 9 March. Just after midnight activity quickly intensified with lava fountaining and a large eruption plume that rose at least 9 km a.s.l. The plume drifted ENE and caused ash and lapilli to fall in Mascali (18 km E), Giarre (17 km ESE), and Fiumefreddo (19 km ENE). Lava reached an elevation of 1,800 m, also effusing from the flank of the S vent. Lava fountaining ceased at 0430 on 10 March and sporadic ash emissions continued until 0700. The twelfth episode began at 0630 on 12 March with Strombolian activity at SEC and ash emissions. The activity intensified at 0754 and lava overflowed the E part of SEC, traveling towards the Valle de Bove. Lava fountaining began at 0841, with jets up to 500 m, and an eruption plume rose 6 km a.s.l. and drifted E. Lava advanced to 2,800 m elevation and within another hour had reached 2,000 m elevation. At 0939 the plume had risen 9-10 km and had caused ashfall in Milo and Fornazzo (10 km E), Giarre, Santa Venerina (15 km SE), and Torre Archirafi (20 km ESE). Lava fountaining ceased at 1050, though weak Strombolian activity and ash emissions continued until 1115. The lava flow advanced as far as 1,700 m elevation and a second lava flow expanded SE on the W slope of the Valle del Bove, stopping at 3,000 m a.s.l.

Krysuvik-Trolladyngja – Iceland : IMO reported that seismicity in the Reykjanes Peninsula remained elevated with thousands of earthquakes recorded during 10-16 March, in the western part of the Krýsuvík-Trölladyngja volcanic system in the Fagradalsfjall fissure swarm area. About 16,500 earthquakes had been detected over the week. Some of the largest events, M 4.3-5.4 recorded during 10-12 and 14-15 March, were felt as far as Hvanneyri (97 km NNE of Grindavik), Hvolsvollur (110 km ESE of Grindavik), and Saudakrokur (250 NE of Grindavik). A few, short-lived pulses of tremor were also recorded. The magma intrusion continued to move SW along a fault between Keilir and Fagradalsfjall, and was as shallow as 1 km below the surface. GPS, satellite, and seismic data indicated that the intrusion had expanded S to Nátthaga, a valley just E of Borgarfjall and S of Fagradalsfjall, and was 3-5 km long. Ground fracturing was visible in the area above the intrusion. The Aviation colour Code for Krýsuvík remained at Orange.

Momotombo – Nicaragua : The Washington VAAC reported that on 14 March a possible ash emission was visible in webcam and satellite data just above Momotombo. Ash was not visible in a subsequent satellite image captured around six hours later.

Pacaya – Guatemala : INSIVUMEH and CONRED reported that pulses of moderate-to-strong Strombolian explosions at Pacaya’s Mackenney Crater were commonly recorded during 9-16 March. Frequent ash plumes rose as high as 2 km and drifted as far as 30 km W, SW, and S. On 10 March lapilli (2 mm to 6 cm in length) fell in El Caracol (3 km SW), and ash fell in El Patrocinio (about 5 km W) and likely in other areas downwind. Ash plumes caused daily ashfall in variable places during 11-16 March, including El Patrocinio, San José El Rodeo, the municipality of San Vicente Pacaya (5 km NW), San Francisco de Sales (5 km N), San José el Bejucal (4 km N), San Antonio el Pepinal (7 km N), Concepción El Cedro (9 km NNW), San José Calderas, and the municipalities of Amatitlán (12 km N), Villa Nueva (16 km N), and Mixco (30 km N). Lapilli as long as 2 cm fell in El Patrocinio, San José El Rodeo and Concepción El Cedro on 16 March. Strombolian explosions and periodic lava fountaining ejected incandescent material as high as 800 m above the summit; tephra fell within a 500 m radius of Mackenney Crater. Explosions and ash emissions also rose from fissures on the S flank, 300 m below Mackenney Crater. The lava flow on the S flank had two branches and was 1 km on 10 March, but had lengthened to 1.8 km by 16 March. Block avalanches from the summit traveled down the S flank.

San Cristobal – Nicaragua : SINAPRED reported that a series of five explosions at San Cristóbal were recorded during 1306-1332 on 9 March. The strongest explosion, at 1325, produced an ash plume that rose 800 m above the crater rim. Ashfall as deep as 2 mm was reported in El Viejo (19 km WSW), Chinandega (16 km SW), and Chichigalapa (16 km S); ash also fell in other communities downwind including Las Grecias, La Mora, and La Bolsa.

Semisopochnoi – Aleutian Islands (USA) : On 12 March AVO reported that although no ash plumes were observed at Semisopochnoi and nothing was detected in regional infrasound data during the previous week, ash deposits within Mount Cerberus’s N crater and extending 1.5 km on the flank were identified in satellite data. The Aviation colour Code and the Volcano Alert Level remained at Yellow/Advisory, respectively.

Taal – Luzon (Philippines) : PHIVOLCS reported that during 10-13 March there were around 51-55 volcanic earthquakes recorded daily at Taal, and about 23-49 periods of volcanic tremor with variable durations. One hybrid earthquake was recorded during 11-12 March. Diffuse steam plumes from fumarolic vents in Main Crater rose only 5 m. Sulfur dioxide emissions were 1,327 tonnes per day on 10 March, and fluctuated between 518 and 795 tonnes per day through 14 March. At 1411 on 12 March a short-lived (2.5 minutes) burst of steam-rich gas from Main Crater generated white plumes that rose 400-500 m. Diffuse steam plumes rose 50 m above fumarolic vents on the inner N and E walls during the rest of the day. The number of volcanic earthquakes per day rose to 74 during 13-14 March and to 252 during 15-16 March. Episodes of tremor persisted, with 17-46 periods recorded per day. Five hybrid events were detected during 14-15 March. An episode of high-temperature gas upwelling to the crater lake’s surface occurred during 1830-2045 on 14 March. Sulfur dioxide emissions were 1,216 tonnes per day on 15 March. Steam emissions rose 10 km during 15-16 March. The seismic network recorded 42 volcanic earthquakes and 34 periods of tremor. The Alert Level for Taal remained at 2 (on a scale of 0-5). PHIVOLCS strongly recommended no entry onto the island, and access to the Main Crater and Daang Kastila fissure (along the walking trail) was strictly prohibited.

Veniaminof – United States : AVO reported that the eruption at Veniaminof continued during 9-16 March. Ash emissions rose to 2.1-3 km (7,000-10,000 ft) a.s.l. and drifted 200 km NE and SE during 9-10 March. Explosions and ash emissions declined to lower levels the rest of the week, though new ash deposits within the caldera, and as far as 10 km SE, were sometimes identified in satellite images. Lava continued to effuse under the intra-caldera glacier in an area on the flank about 1 km E of the cone’s summit. Elevated surface temperatures over this area were identified in a satellite images during most days, along with steam plumes and a broadening collapse pit in the ice from melting around the eruption site. Data from local seismic stations were back online by 12 March and showed elevated seismicity and tremor through 15 March. Steam-and-has plumes were identified in satellite images during 15-16 March. The Volcano Alert Level remained at Watch and the Aviation colour Code remained at Orange.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 3 March 2021 – 9 March 2021

Aira – Kyushu (Japan) : JMA reported that during 1-8 March incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible nightly. An explosion at 1810 on 1 March ejected bombs 600-900 m away from the crater; an eruption plume was not confirmed. That same day the sulfur dioxide emission rate was high, at 2,900 tons per day. An explosion on 5 March produced an eruption plume that rose 2.7 km above the summit and ejected bombs 800-1,100 m away. The Alert Level remained at 3 (on a 5-level scale).

Dukono – Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that during 7-9 March ash plumes from Dukono rose to 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted E, SE, and SW. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Ebeko – Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 26-28 February and 1-2 March that sent ash plumes to 3.6 km (11,800 ft) a.s.l. and drifted in multiple directions. Ashfall was reported in Severo-Kurilsk on 26 February and 2 March. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Kikai – Japan : In response to an eruption at Satsuma Iwo-jima, a subaerial part of Kikai’s NW caldera rim, on 2 November 2019 JMA had raised the Alert Level to 2 (on a 5-level scale). Since then, surveillance cameras sometimes recorded minor incandescence reflected in emitted plumes. On 8 March JMA revised the Alert Level guidelines, keeping the level at 2, but reducing the exclusion zone around the crater from 1 km to 500 m.

Kilauea – Hawaiian Islands (USA) : HVO reported that a vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 2-8 March through a submerged inlet. The sulfur dioxide emission rate was 1,000 tons/day during 2-3 March, and 800 tons/day on 7 March. The depth of the western part of the lake fluctuated around 219-220 m. The E half of the lake remained solidified and lower that the W half, with the crusted E half expanding towards the W. Rangefinder measurements and visual observations indicated that the eastern and western portions of the lake were rising at the same rate, suggesting that lava was accumulating under the crusted eastern portion. In recent weeks a part of the cone, several meters NE of the main vent, occasionally fed short (less than 100 m) lava flows that entered the lake at the crusted margins. During 5-7 March flows from this vent poured lava into the lake at several shifting inlets, though lava also accumulated on the lake margin within 50 m of the vent. By midday on 7 March the flows had built a perched lava pond on the NW lake margin, but it abruptly collapsed just after 1300. The Aviation colour Code remained at Orange and the Volcano Alert Level remained at Watch.

Lewotolo – Lomblen Island (Indonesia) : PVMBG reported that the eruption at Lewotolok continued during 3-9 March; weather conditions sometimes hindered visual observations. Gray-and-white ash plumes rose 100-1,000 m above the summit and drifted E, SE, SW, and W. Incandescent material was ejected 300-800 m SE from the crater during 3-6 March. Rumbling and occasional thumping sounds were reported. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 4 km away from the summer crater.

Merapi – Central Java (Indonesia) : BPPTKG reported that the 2021 lava dome just below Merapi’s SW rim and the new lava dome in the summit crater both continued to grow during 19-25 February. The 2021 lava-dome volume was an estimated 618,700 cubic meters on 25 February, with a growth rate of about 13,600 cubic meters per day. A total of three pyroclastic flows traveled 1.9 km down the SW flank. One of the three, recorded at 1652 on 25 February, was followed by minor ashfall in Kali Tengah Lor, Kali Tengah Kidul, Deles, and Tlukan. The Alert Level remained at 3 (on a scale of 1-4), and the public were warned to stay 5 km awa

Raung – Eastern Java (Indonesia) : PVMBG reported that daily gray ash plumes rose 200-1,200 m above Raung’s summit during 2-9 March. Ash plumes drifted mainly E and S. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Sangay – Ecuador : IG reported a high level of activity at Sangay during 3-9 March. Seismicity was characterized by daily explosions, long-period earthquakes, and signals indicating emissions. Weather clouds often prevented visual observations of the volcano, but satellite and webcam images recorded daily ash plumes. Ash plumes were notable during 5-6 March and impacted communities downwind with ashfall. According to the Washington VAAC ash plumes rose 5.8-12.2 km (19,000-40,000 ft) a.s.l. and drifted 170-370 km SW, W, and NW; ash at altitudes of 5.8-8.2 km (19,000-27,000 ft) a.s.l. drifted 185 km E. During 5-6 March ashfall was reported in Alfredo Baquerizo Moreno (132 km W), but fell more significantly in Alausí (61 km WSW), Chunchi (73 km SW), Cumandá (90 km WSW), Guamote (42 km WNW), Pallatanga (70 km W), Milagro (140 km W), San Jacinto de Yaguachi (150 km W), Samborondon (170 km W), Daule (180 km W), and Durán (168 km W). SNGRE reported that the ashfall affected a total of 108,457 people (23,750 families) as well as numerous crops and animals; they distributed volcano-related aid kits to impacted populations. Ashfall continued to impact multiple communities during 6-7 March. Ash fell in Guayaquil (175 km W), General Antonio Elizalde (97 km WSW), Simón Bolívar, Milagro (140 km W), San Jacinto de Yaguachi (150 km W), El Triunfo (125 km WSW), Daule, Samboróndon (170 km W), Coronel Marceliño Maridueña (120 km WSW), Durán, Naranjito, Alfredo Baquerizo Moreno, Playas (240 km WSW), Guamote (40 km WNW), Alausí (60 km SW), Pallatanga (70 km W), Chunchí (72 km SW), and Colta (55 km NW).

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 26 February-5 March. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Soufriere St. Vincent – St. Vincent : University of the West Indies Seismic Research Centre (UWI-SRC) and National Emergency Management Organisation (NEMO) reported that the lava dome in Soufrière St. Vincent’s main crater continued to slowly grow during 2-8 March. The SE part of the dome was in line with the pre-existing fumarolic area on the 1979 dome. Gas plumes continued to damage vegetation in the summit area as well as on the SW flank. The Alert Level remained at Orange (the second highest level on a four-colour scale).

Suwanosejima – Ryukyu Islands (Japan) : JMA reported intermittent eruptive events at Suwanosejima’s Ontake Crater during 26 February-2 March. Bombs were ejected as far as 600 m away from the crater and ashfall was reported in Toshima village (4 km SSW). The number of explosions began increasing on 2 March; the total recorded through 1500 on 7 March was 139, but by 1500 on 8 March there was only one additional explosion. The Tokyo VAAC reported that ash plumes rose 0.9-2.1 km (3,000-7,000 ft) a.s.l. during 3-7 March. An explosion at 0317 on 6 March ejected tephra as high as 500 m above the crater rim and bombs 900 m away. The Alert Level remained at 2 (on a 5-level scale).

Volcanos

Roundup of Global Volcanic Activity – New Activity for the Week 3 March 2021 – 9 March 2021

Etna – Sicily (Italy) : INGV reported continuing episodes of lava fountaining at Etna’s Southeast Crater (SEC) on 2, 4, and 7 March. Weak Strombolian activity began at SEC at 1145 on 2 March, then intensified at 1234 and produced an ash plume. Lava fountaining began at 1324. Ash plumes rose to 9 km above the summit and drifted S, causing lapilli to fall in Nicolosi (16 km S), Aci San Antonio (18 km SE), Pedara (15 km SSE), and Catania (29 km SSE). Lava fountaining ceased at 1550, ending the eighth episode.

Krysuvik – Iceland : IMO reported that seismicity in the area between the Krýsuvík and Reykjanes-Svartsengi volcanic systems remained elevated during 4-10 March. GPS and InSAR data indicated that the intrusion was ongoing, with magma moving slowly SW along a fault between Keilir and Fagradalsfjall at depths of 2-6 km. Seismicity fluctuated during 6-7 March but continued to be elevated; the largest event was a M 5.1 on 7 March. The geophysical and satellite data on 8 March suggested that magma movement had decelerated over the past week, and was possibly as shallow as 1 km. A burst of seismicity was recorded around 0520 on 9 March, concentrated at the S end of the intrusion in an area that was most likely source of the magma. On 10 March IMO stated that more than 34,000 earthquakes had been detected during the past two weeks, a total larger than all of 2020 which was characterized as an unusually high year for seismicity. The Aviation Color Code for Krýsuvík remained at Orange.

Pacaya – Guatemala : INSIVUMEH and CONRED reported that during 2-6 March strong Strombolian explosions at Pacaya’s Mackenney Crater produced ash plumes that rose as high as 1 km above the summit and drifted W, SW, and S. Tephra fell in areas downwind including El Patrocinio (5 km W), El Rodeo (4 km WSW), San Francisco de Sales (5 km N), El Cedro (9 km NNW), Calderas (3 km N), and Las Jazmines (5 km W), and in the municipalities of Palín (10 km WNW) and Escuintla (22 km SW). Periods of lava fountaining were visible, and incandescent material was ejected 300-1,000 m high. Three lava flows were active and all had several branches; one traveled SSW, one traveled S, and one on the SE flank was 800-1,200 m long. During 6-8 March strong explosions ejected material as high as 500 m and produced dense ash plumes that rose up to 1 km. Lava flows continued to be active, sometimes producing block avalanches from the ends. On 8 March the S-flank flow was about 850 m long and continued to generated block avalanches. Strong explosions during 8-9 March ejected ballistics 300-500 m away from the crater. Dense ash plumes rose up to 1.5 km and drifted 30 km SW and S. The lava flow on the S flank was 900 m long and shed blocks from the end.

Pinatubo – Luzon (Philippines) : PHIVOLCS raised the Alert Level for Pinatubo to 1 (on a scale of 0-5) on 4 March noting elevated seismicity with a total of 1,722 earthquakes recorded in two swarms since 20 January. The first swarm was recorded during 20-26 January and was comprised of local M 1-2.5 events that occurred along the Sacobia Lineament fault at depths of 15-28 km. A more persistent swarm followed; it was comprised of local M 0.5-2.8 events at depths of 10-35 km along another fault system, with a few shallower earthquakes occurring at both ends of the swarm. Carbon dioxide flux at Pinatubo Crater lake was 378 tonnes per day in February, within background ranges that topped 1,000 tonnes per day during the last decade. Minor temperature increases were recorded at fumarolic vents.

Sinabung – Indonesia : PVMBG reported that the eruption at Sinabung continued during 3-9 March. According to the Darwin VAAC an ash plume was identified in satellite images rising to 3 km (10,000 ft) a.s.l. (or 600 m above the summit) and drifting NW on 5 March. The observatory noted that avalanches of material traveled 500 m down the SE flank during 6-7 March, and an ash plume rose 1 km and drifted NW at 1910 on 7 March. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km in the SE sector and 4 km in the NE sector.

Taal – Luzon (Philippines) : PHIVOLCS raised the Alert Level for Taal to 2 (on a scale of 0-5) on 9 March based on increased activity recorded since 13 February. During 8-9 March the seismic network recorded a total of 28 volcanic tremor events, four low-frequency volcanic earthquakes, and one hybrid event at depths of less than 1.5 km. These events added to the totals of 866 volcanic tremor events and 141 low-frequency volcanic earthquakes recorded during 13 February-9 March. Overall, seismicity over the past month indicated increased magmatic and hydrothermal activity at shallow depths beneath Taal Volcano Island (TVI).

Klyuchevskoy – Central Kamchatka (Russia) : KVERT reported that the eruption from vents on Klyuchevskoy’s lower NW flank continued during 26 February-5 March. A large, bright thermal anomaly over the vents was identified daily in satellite images. IVS FEB RAS volcanologists visited the field site on 2 March during good weather conditions. They estimated that the cinder cone was 54 m high and 101 m wide at the base. Lava effused from the cone and traveled downslope, melting ice and snow that formed muddy streams. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Veniaminof – United States : AVO reported that elevated sulfur dioxide gas emissions at Veniaminof were first detected on 1 March and elevated surface temperatures were identified in satellite images sometime during 2-3 March. At 0513 on 4 March infrasound sensors recorded a small explosion, prompting AVO to raise the Volcano Alert Level to Watch and the Aviation Color Code to Orange. A low-level ash plume, to less than 3 km (10,000 ft) a.s.l., was visible in satellite and webcam images drifting SSE and minor ash deposits around the volcano were visible. Small emissions continued at least through 1048 that day. Sulfur dioxide emissions were visible in a webcam image on 5 March. Numerous small explosions were recorded during 6-7 March; some of them were heard and felt by residents in Perryville (35 km SE). Elevated surface temperatures were identified in satellite images, suggesting lava near or at the surface. During times of clear weather low-level gas-and-ash plumes were visible in satellite and webcam data and observed by pilots. The plumes mainly stayed below 3 km (10,000 ft) a.s.l., but at times went as high as 4.6 km (15,000 ft) a.s.l., and drifted 150 km NE.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 24 February 2021 – 2 March 2021

Aira – Kyushu (Japan) : JMA reported that during 22 February-1 March incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible nightly. Three explosions and four non-explosive events generated eruption plumes that rose as high as 2.6 km above the crater rim and ejected bombs 0.6-1.3 km away from the crater. The Alert Level remained at 3 (on a 5-level scale).

Dukono – Halmahera (Indonesia) : PVMBG reported that during 23-28 February ash plumes from Dukono rose 100-500 m above the summit and drifted SE and E. Weather conditions prevented visual observations during 1-2 March. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Ebeko – Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 19-26 February that sent ash plumes to 3.6 km (11,800 ft) a.s.l. and drifted E and SE. Ashfall was reported in Severo-Kurilsk on 20 February and a thermal anomaly was identified in satellite images that same day. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Fuego – Guatemala : INSIVUMEH reported that 5-15 explosions were recorded per hour during 23 February-2 March at Fuego, generating ash plumes as high as 1.1 km above the crater rim. Shock waves rattled buildings around the volcano. Block avalanches descended the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), Las Lajas (SE), and Honda drainages, often reaching vegetated areas. Ashfall was reported on most days in several areas downwind including Morelia (9 km SW), Panimaché I (8 km SW), Santa Sofía (12 km SW), El Porvenir (8 km ENE), and San Pedro Yepocapa (8 km NW). Incandescent material was ejected 100-400 m above the summit almost daily. Curtains of old ash deposits remobilized by strong winds were observed during 26-27 February.

Ibu – Halmahera (Indonesia) : PVMBG reported that during 24 February-2 March gray-and-white ash plumes from Ibu rose 200-800 m above the summit and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater and 3.5 km away on the N side.

Kilauea – Hawaiian Islands (USA) : HVO reported that a vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 24 February-2 March. The depth of the western part of the lake deepened from 217 to 219 m. Lava effused from a submerged vent and rapidly developed a thin crust as it flowed E towards the main stagnant island. The crust occasionally overturned at “plate” boundaries, and lava rarely overflowed onto the sloped margins of the lake. The E half of the lake remained solidified; the crusted area expanded towards the W. The sulfur dioxide emission rate was 700-1,100 tons/day during 25-26 February and 1 March.

Kirishimayama – Kyushu (Japan) : JMA lowered the Alert Level for Kirishimayama to 1 (on a scale of 1-5) on 1 March. The number of volcanic earthquakes had increased in late December 2020 but then began to decline in January 2021 and continued the downward trend through February. No other observation data showed signs of unrest.

Lewotolo – Lomblen Island (Indonesia) : PVMBG reported that the eruption at Lewotolok continued during 24 February-2 March; weather conditions sometimes hindered visual observations. Gray-and-white ash plumes rose 100-700 m above the summit and drifted N, E, SE, and W. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 4 km away from the summer crater.

Merapi – Central Java (Indonesia) : BPPTKG reported that the 2021 lava dome just below Merapi’s SW rim and the new lava dome in the summit crater both continued to grow during 19-25 February. The 2021 lava-dome volume was an estimated 618,700 cubic meters on 25 February, with a growth rate of about 13,600 cubic meters per day. A total of three pyroclastic flows traveled 1.9 km down the SW flank. One of the three, recorded at 1652 on 25 February, was followed by minor ashfall in Kali Tengah Lor, Kali Tengah Kidul, Deles, and Tlukan. The Alert Level remained at 3 (on a scale of 1-4), and the public were warned to stay 5 km away from the summit.

Raung – Eastern Java (Indonesia) : PVMBG reported that daily gray ash plumes rose 200-1,200 m above Raung’s summit during 24 February-2 March. Ash plumes were sometimes dense and drifted mainly N, E, and S. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone.

Sangay – Ecuador : IG reported a high level of activity at Sangay during 24 February-2 March. Seismicity was characterized by 3-254 daily explosions, long-period earthquakes, and signals indicating emissions. Weather clouds often prevented visual observations of the volcano, but the Washington VAAC recorded almost daily ash plumes that rose as high as 1.5 km above the summit and drifted mainly NW, W, and SW. A seismic station possibly recorded a lahar on 25 February.

Santa Maria – Guatemala : INSIVUMEH reported that during 23 February-2 March explosions at Santa María’s Santiaguito lava-dome complex generated ash plumes that rose as high as 1 km above the complex. Collapses of blocky lava from the Caliente dome sent avalanches mainly down the SW flank, often reaching the base of the complex. Minor pyroclastic flows were occasionally generated. Ash plumes drifted W and SW, often causing minor ashfall around the volcano.

Semeru – Eastern Java (Indonesia) : The Darwin VAAC reported that during 24-25 February ash plumes from Semeru rose to 4-4.3 km (13,000-14,000 ft) a.s.l. and drifted SE based on satellite images. PVMBG noted that weather conditions prevented visual observations during 24 February-2 March. The Alert Level remained at 2 (on a scale of 1-4), with a general exclusion zone of 1 km and extensions to 4 km in the SSE sector.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 19-26 February. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Soufriere St. Vincent – St. Vincent : University of the West Indies Seismic Research Centre (UWI-SRC) and National Emergency Management Organisation (NEMO) reported that the lava dome in Soufrière St. Vincent’s main crater continued to grow during 24 February-2 March. The rate of growth was variable, though overall slow. Gas emissions continued to damage vegetation in the summit area as well as on the SW flank. The monitoring teams replaced a camera and continue to improve the seismic and GPS networks. The Alert Level remained at Orange (the second highest level on a four-colour scale).

Suwanosejima – Ryukyu Islands (Japan) : JMA reported intermittent eruptive events at Suwanosejima’s Ontake Crater during 19-26 February. These events produced ash plumes that rose as high as 1.8 km above the crater rim and ejected bombs 200 m away from the crater. Ashfall was reported in Toshima village (4 km SSW). The Alert Level remained at 2 (on a 5-level scale).

Volcanos

Roundup of Global Volcanic Activity – New Activity for the Week 24 February 2021 – 2 March 2021

Etna – Sicily (Italy) : INGV reported continuing episodes of lava fountaining at Etna’s Southeast Crater (SEC) and 24 and 28 February. Strombolian activity at two vents in SEC increased during the late afternoon of 24 February. Lava overflowed the crater at 1820 and headed ESE towards the Valle de Bove. During 1900-2122 lava fountains rose as high as 500 m above the summit. A second lava flow traveled SW, and at 2100 a pyroclastic flow descended 1 km into the Valle de Bove. An eruption plume rose as high as 11 km a.s.l. Weak Strombolian activity was visible at 0810 on 28 February. Lava fountaining began at 0839, feeding lava flows that traveled E, and abruptly intensified at 0902 with jets of lava rising 700 m above the crater rim. An eruption plume rose as high as 11 km a.s.l. and drifted ESE, causing ashfall in areas downwind. A small lava overflow at the S part of SEC began at 0909, followed by a pyroclastic flow at 0920. Lava fountaining ended at 0933, though the lava flow descending E remained active.

Klyuchevskoy – Central Kamchatka (Russia) : KVERT reported that the eruption at two vents on Klyuchevskoy’s lower NW flank continued during 24-26 February. Both vents produced lava flows and ejected lava 50 m high. A cinder cone had formed over the higher vent. A bright thermal anomaly over the vents was identified in satellite images. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Krysuvik – Iceland : IMO reported that seismicity in the area between Krýsuvík and Reykjanes-Svartsengi volcanic systems remained elevated during 26 February-1 March. More than 6,000 earthquakes had been detected after a M 5.7 event was recorded at 1005 on 24 February; two of those events were above M 5. The earthquakes were distributed over a 25-km-long section of a N-S striking fault along the E-W striking plate boundary, primarily located between Keilir and Fagradalsfjall. GPS data showed 4 cm of horizontal displacement near the epicenter of the M 5.7 event. An InSAR interferogram showed left-lateral movement over a large section of the plate boundary. Tremor began to be recorded by several stations at 1425 on 3 March, in an area located 2 km SW of Keilir. The signals possibly indicated magma rising towards the surface and prompted IMO to raise the Aviation Color Code for Krýsuvík to Orange.

Kuchinoerabujima – Ryukyu Islands (Japan) : JMA reported that the number of volcanic earthquakes located at shallow depths beneath Kuchinoerabujima’s Shindake Crater increased on 21 February and remained elevated. The Alert Level was raised to 3 (the middle level on a scale of 1-5) on 28 February. No other monitoring data showed upward trends and no surficial changes were visible; sulfur dioxide emissions remained low at 60 tons per day on 24 February.

Pacaya – Guatemala : INSIVUMEH and CONRED reported that during 23-25 February explosions at Pacaya’s Mackenney Crater ejected incandescent material as high as 200 m. A lava flow, originating from a vent 300 m below the summit crater, was about 1.1 km long and produced incandescent blocks from the flow front that descended 300 m. more intense pulses of activity at the summit produced dense ash plumes that drifted more than 30 km S and SW. Ashfall was noted in areas downwind including Los Pocitos, Pacaya, El Rodeo, and El Patrocinio. Explosions continued during 26-29 February, although weather conditions sometime prevented visual confirmation. RSAM data values notably increased during the morning of 1 March, reflecting an increase in Strombolian activity. Moderate-to-strong explosions ejected ballistics as high as 500 m above the summit. Ash plumes rose 1 km above the summit and drifted W and SW, causing ashfall at least in El Patrocinio. Incandescent material was ejected 150 m high, and ash plumes drifted W; ashfall was reported in El Patrocinio. The lava flow on the SSW flank was about 700 m long. On 2 March gas and ash plumes rose 150 m and drifted 2 km S. A lava flow on the SSW flank was 150 m long.

Sinabung – Indonesia : PVMBG reported that the eruption at Sinabung continued during 24 February-2 March. White plumes rose as high as 500 m above the summit most days. On 25 February avalanches of material traveled 500-1,000 m down the E, SE, and S flanks. The Darwin VAAC noted that an ash plume rose to 4 km (13,000 ft) a.s.l., or 1.5 km above the summit, and drifted SE, based on satellite images and information from PVMBG. On 28 February avalanches of material traveled 1,000-1,250 m down the E, SE, and S flanks; the VAAC noted that ash plumes were visible in satellite images and rose to 3.4 km (11,000 ft) a.s.l. (about 1 km above the summit) and drifted SW. On 1 March avalanches of material descended the E, SE, and S flanks as far as 1.3 km. A series of lava-dome collapses began at 0642 on 2 March. A total of 13 pyroclastic flows, each lasting between about two and eight minutes, traveled 2-5 km SE and E. Ash plumes rose 4-5 km along the length of the pyroclastic flows and drifted W, SW, S, and E. The VAAC reported that ash plumes were visible in satellite images beginning at 0640 rising to 4.3 km (14,000 ft) a.s.l. and drifting SW. Ash plumes rose to 7.6 km (25,000 ft) a.s.l. and drifted W by 0758; within another 25 minutes the plumes had risen to 12.2 km (40,000 ft) a.s.l. According to BNPB ashfall was noted in 17 villages in the Tiganderket District, eight villages in the Kutabuluh District, and 15 villages in the Tigabinaga District. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km in the SE sector and 4 km in the NE sector.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 17 February 2021 – 23 February 2021

Aira – Kyushu (Japan) : JMA reported that during 15-22 February incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible nightly. An explosion on 16 February generated an eruption plume that rose 1 km above the crater rim and ejected bombs 1-1.3 km away from the crater. That same day the sulfur dioxide emission rate was extremely high, at 4,300 tons per day. An ash plume from an explosion at 2253 on 21 February rose 1.6 km and entered weather clouds. Large bombs were ejected 800-1,100 m away from the crater. The Alert Level remained at 3 (on a 5-level scale).

Ebeko – Paramushir Island (Russia) : Volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, observed explosions during 12, 14-15, and 17 February that sent ash plumes to 2.1 km (6,900 ft) a.s.l. and drifted E and SE. Ashfall was reported in Severo-Kurilsk on 15 February and a thermal anomaly was identified in satellite images on 17 February. The Aviation colour Code remained at Orange (the second highest level

Fuego – Guatemala : INSIVUMEH reported that 4-12 explosions were recorded per hour during 17-23 February at Fuego, generating ash plumes as high as 1.1 km above the crater rim. Shock waves rattled buildings around the volcano. Block avalanches descended the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), Las Lajas (SE), and Honda drainages, often reaching vegetated areas. Ashfall was reported on most days in several areas downwind including Morelia (9 km SW), Panimaché I (8 km SW), Santa Sofía (12 km SW), El Porvenir (8 km ENE), and San Pedro Yepocapa (8 km NW). Notably, on 17 February ash plumes drifted as far as 50 km E, causing ashfall in local communities as well as in Guatemala City (city center is about 40 km ENE). Ash plumes drifted 40 km SW on 18 February. Curtains of old ash deposits remobilized by strong winds were observed during 19-21 February. Incandescent material was ejected 100-400 m above the summit during 19-22 February.

Ibu – Halmahera (Indonesia) : PVMBG reported that on most days during 17-23 February gray-and-white ash plume from Ibu were seen rising 200-800 m above the summit and drifting in multiple directions. Weather conditions sometimes hindered observations. The report stated that during 16-17 February there were a total of 88 eruptive events. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater and 3.5 km away on the N side.

Kilauea – Hawaiian Islands (USA) : HVO reported that a vent on the inner NW wall of Kilauea’s Halema`uma`u Crater continued to supply the lava lake during 17-23 February. The depth of the western part of the lake fluctuated between 215 and 218 m and the lake surface actively overturned at “plate” boundaries. The sulfur dioxide emission rate was elevated at 1,000 tons/day on 19 February.

Lewotolo – Lomblen Island (Indonesia) : PVMBG reported that the eruption at Lewotolok continued during 16-23 February; weather conditions sometimes hindered visual observations. Gray-and-white ash plumes rose 50-500 m above the summit and drifted E and SE. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 4 km away from the summer crater.

Merapi – Central Java (Indonesia) : BPPTKG reported that the 2021 lava dome just below Merapi’s SW rim and the new lava dome in the summit crater both continued to grow during 12-18 February. The 2021 lava dome volume was an estimated 397,500 cubic meters on 17 February, with a growth rate of about 25,200 cubic meters per day; it was 258 m long, 133 m wide, and 30 m high. The summit lava dome was an estimated 426,000 cubic meters, with a growth rate of about 10,000 cubic meters per day; it was 160 m long, 120 m wide, and 50 m high. Seismicity was less intense than the previous week. Electronic Distance Measurement (EDM) data showed no notable deformation. PVMBG noted that foggy conditions often prevented visual observations during 18-23 February, though sometimes white emissions were observed rising up to 400 m above the summit. The Alert Level remained at 3 (on a scale of 1-4), and the public were warned to stay 5 km away from the summit.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported a daily average of 71 explosions at Sabancaya during 15-21 February. Gas-and-ash plumes rose as high as 3.2 km above the summit and drifted in multiple directions. Ten thermal anomalies originating from the lava dome in the summit crater were identified in satellite data. Minor inflation continued to be detected in areas N of Hualca Hualca (4 km N). The Alert Level remained at Orange (the second highest level on a four-colour scale) and the public were warned to stay outside of a 12-km radius.

Semeru – Eastern Java (Indonesia) : PVMBG reported that the eruption at Semeru continued during 17-23 February, though weather conditions often prevented visual confirmation. At 0601 on 17 February an ash plume rose 300 m and drifted N. A white-and-gray ash plume rose 100 m and drifted N, NE, and E on 18 February. The Alert Level remained at 2 (on a scale of 1-4), with a general exclusion zone of 1 km and extensions to 4 km in the SSE sector.

Semisopochnoi – United States : AVO reported that no significant activity at Semisopochnoi was recorded after several ash deposits were visible in satellite images during 6-7 February. On 19 February the Aviation colour Code and the Volcano Alert Level were lowered to Yellow/Advisory, respectively.

Sheveluch – Central Kamchatka (Russia) :KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 12-19 February. The Aviation colour Code remained at Orange (the second highest level on a four-colour scale).

Sinabung – Indonesia : PVMBG reported that the eruption at Sinabung continued during 17-23 February, though weather conditions sometimes prevented visual confirmation. White plumes rose as high as 1 km above the summit and drifted in multiple directions. On 21 February pyroclastic flows traveled as far as 2 km down the E and SE flanks. The Alert Level remained at 3 (on a scale of 1-4), with a general exclusion zone of 3 km and extensions to 5 km in the SE sector and 4 km in the NE sector.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported intermittent eruptive events at Ontake Crater during 12-19 February. These events produced ash plumes that rose as high as 1.5 km above the crater rim and ejected bombs 300 m away from the crater. The Alert Level remained at 2 (on a 5-level scale).

Whakaari/White Island – North Island (New Zealand) : GeoNet reported that beginning around 0220 on 19 February a series of short-lived, low-energy steam explosions at Whakaari/White Island were recorded for about 100 minutes by local seismic and acoustic instruments. Webcam images were dark due to the time of day; no trace ash deposits were visible. Tremor had begun around 2100 the night before and then ceased at 0550 when the steam explosions ended. Visual observations and gas flux measurements taken during an overflight on 18 February showed no changes compared to the previous month. The Volcanic Alert Level remained at 1 and the Aviation colour Code remained at Green.