Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 24 November – 30 November 2021

Aira ; Kyushu (Japan) : JMA reported that incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible at night during 22-29 November. An eruptive event at 1509 on 25 November generated a plume that rose 1 km above the crater rim. The sulfur dioxide emission rate was slightly high at 1,200 tons per day on 26 November; sulfur dioxide emissions had been generally high since late September 2020.

Bagana ; Bougainville (Papua New Guinea) : The Darwin VAAC reported that on 27 November ash plumes from Bagana rose to 2.1 km (7,000 ft) a.s.l. and drifted NW based on satellite and wind model data.

Ebeko ; Paramushir Island (Russia) : On 26 November KVERT lowered the Aviation Color Code for Ebeko to Yellow (the second lowest level on a four-color scale), noting that a thermal anomaly was last identified on 25 October and eruptive activity was last recorded on 9 November. Gas-and-steam emission continued to be visible.

Etna – Sicily (Italy) : INGV reported that gas emissions from Etna’s summit craters were visible during 15-21 November, though weather clouds sometimes prevented webcam observations. At 1116 on 20 November an explosion at Northeast Crater (NEC) produced diffuse ash-and-gas plumes that quickly dissipated near the summit.

Great Sitkin – Andreanof Islands (USA) : According to AVO satellite images acquired on 23 November showed that lava effusion at Great Sitkin continued, though at a low rate. Lava continued to fill the summit crater and the flows on the flanks advanced short distances. During 24-30 November seismicity remained slightly above background levels. Elevated surface temperatures were periodically detected.

Grimsvotn – Iceland : On 24 November Icelandic Meteorological Office (IMO) reported that the ice sheet in Grímsvötn’s caldera had subsided 60 cm in the previous few days and the rate of subsidence had accelerated in the last day. By 29 November the ice had sunk a total of 5 m and by 1 December the subsidence totaled 10 m. Data indicated that water had likely begun exiting the caldera and will result in a jökulhlaup (glacial outburst flood) that will cause flooding conditions in drainages. Water levels in the Gígjukvísl drainage rose overnight during 30 November-1 December.Roads, including several national highways, have been cut by flooding or landslides. Wide areas of agriculture along with livestock have suffered damage.

Katmai – United States : AVO reported that on 25 November strong winds in the vicinity of Katmai and the Valley of Ten Thousand Smokes blew unconsolidated ash SE over Shelikof Strait and Kodiak Island at an altitude up to 1.5 km (5,000 ft) a.s.l. The ash was originally deposited during the Novarupta eruption in 1912.

Kilauea – Hawaiian Islands (USA) : HVO reported that the summit eruption at Kilauea continued at a vent in the lower W wall of Halema`uma`u Crater during 24-30 November. The vent contained ponded and sometimes spattering lava that fed the lake through the E part of the W wall cone. The size of the active part of the lake varied, and lava periodically oozed from the cooler, outer margins of the lake onto the lowest of the exposed down-dropped caldera floor blocks. Earthquake activity remained below background levels and volcanic tremor was elevated. The sulfur dioxide emission rate had averaged 3,000 tonnes per day in recent weeks; on 23 November the rate was higher at 6,400 tonnes per day and on 29 November it was below the average at 1,200 tonnes per day.

La Palma – Spain : The eruption at La Palma continued during 24-30 November, characterized by Strombolian explosions and lava fountaining/jetting from multiple existing and new vents, advancing and sometimes branching lava flows, and daily ash emissions. The eruption began on 19 September and had been active for 70 days by 28 November. Volcanic tremor levels were low, though during 28-29 November levels fluctuated and were sometimes intense. Seismicity persisted at variable but elevated levels, with earthquake locations distributed at depths of 10-15 km and 30-40 km. Deeper seismicity decreased to low levels by 27 November while mid-level seismicity intensified through the week. The largest earthquake was a M 5 recorded at 0935 on 29 November at a depth of 36 km. A M 4.2 earthquake at a depth of 13 km was the largest event at mid-levels since the eruption began. Several vents in the main cone continued to effuse lava, eject tephra, and emit ash-and-gas plumes. Lava moved W through pre-existing lava channels, lava tubes, over older flows, and over new ground, increasing the flow field that consists of overlapping flows (numbered 1-11) and two lava deltas. During 23-25 November flows 4, 5, and 7 at the N end of the flow field continued to widen and advance, filling in gaps between the flows, and fed the N delta. Flows 1, 2, and 9 minimally fed the S delta. There was also an increasing number of active flows on the flow field as lava overflowed some channel margins or broke out of tubes. At around 0900 on 25 November the lava effusion rate increased at main crater vents, and around 1100 two small E-W fissures opened less than 1 km S of the main cone. The easternmost vent produced a fast-moving lava flow that traveled along the S margin of flow 10 and around the S side of Montaña Cogote. The flow advanced through the Las Manchas cemetery and inundated parts of a solar power plant; the newly covered areas were part of the exclusion zone and had already been evacuated. The flow rate slowed to about 25 m per hour and joined flow 11 by 26 November. An overflow of lava SW of flow 3 produced a small branch oriented laterally the flow margin. Flow 7 widened during 26-27 November as it continued to be fed. New vents opened on the NE flank of the main cone at around 0300 on 28 November, producing fluid lava flows that traveled N and NW through the Tacande area and crossed the LP-212 road. The opening of the new vents was followed by landslides on the NW flank of the cone. In a video taken at 1145 lava fountains rose from one of the vents while another ejected tephra. Dense billowing ash plumes rose from the main crater. Video taken at 1050 on 29 November showed lava flows transporting large blocks downslope. Another video showed lava flowing at a rate of about 1 m per second. By noon the vents in the main cone became notably less active and remained only intermittently active through 30 November. Several streams of lava from the new vents continued to advance NW and then W along older flows and split into two branches. One branch traveled through tubes and fed flows 4, 5, and 7 between Montaña de Todoque and Montaña de La Laguna and the other descended towards flow 8 (the most northern flow). Flows inundated previously untouched forest and agricultural land. By 30 November the width of the flow field had grown to 3.35 km and lava covered an estimated 11.34 square kilometers. The number of people that had evacuated and were staying in hotels had increased to 537. Gas and ash emissions again impacted island residents. Suspended ash and high concentrations of volcanic gases triggered a few air-quality alerts mostly affecting the W part of the island; authorities warned residents of some affected areas to stay indoors. Essential personnel were occasionally barred from entering the exclusion zones to irrigate crops and remove ash from streets and buildings. Heavy rains during 25-26 November triggered warnings from authorities to stay away from steep slopes and drainages due to the possibility of lahars. Ash plumes rose as high as 4.8 km and drifted E during 24-26 November, and continued to deposit ash at La Palma airport. By 27 November winds had shifted and the ash at the airport had been removed, allowing it to open for the first time since 20 November. Ash plumes rose 1.4-3.5 km and drifted SW and SSW during the rest of the week. Sulfur dioxide emissions continued an overall downward trend during 23-26 November, though heavy rain sometimes prevented ground-based measurements. The trend was broken on 27 and 28 November with values of 30,000-49,999 tons per day, characterized as “very high.” During 29-30 November emission values were “high” or between values of 1,000 and 29,999 tons per day.

Lewotolok – Lembata Island (Indonesia) : PVMBG reported that the eruption at Lewotolok continued during 24-30 November. Daily white-and-gray ash plumes rose as high as 1 km above the summit. Crater incandescence was visible each day, with eruptions accompanied by rumbling and roaring sounds. Incandescent material was ejected 300-500 m E and SE from the vent during 24-25 November.

Merapi – Central Java (Indonesia) : BPPTKG reported no notable morphological changes to Merapi’s SW lava dome, located just below the SW rim, or the dome in the summit crater during 19-25 November. The estimated dome volumes remained stable at 1.61 million cubic meters for the SW dome and almost 2.93 million cubic meters for the summit dome. As many as 110 lava avalanches traveled a maximum of 2 km SW. One pyroclastic flow traveled 1.8 km SW on 20 November.

Nyiragongo – DR Congo : OVG reported that active vents on the crater floor of Nyiragongo were seen ejecting spatter on 27 November.

Pavlof – United States : AVO reported that the eruption at Pavlof continued during 23-30 November, focused at a vent on the upper SE flank. Low lava fountaining that had begun on 14 November continued to construct an unstable cone over the vent. Hot rubbly lava flows from the cone traveled a few hundred meters down the flanks, melting snow and ice that resulted in narrow lahars which traveled several kilometers down the flanks; satellite data from 25 November showed a new debris flow extending downslope from the end of the lava flow. Seismicity remained elevated; a few small explosions were detected during 24-26 and 28-30 November. Elevated surface temperatures were periodically observed in satellite data, though cloud cover sometimes prevented observations.

Reventador – Ecuador : IG reported that a high level of activity continued to be recorded at Reventador during 24-30 November. Gas-and-ash plumes, often observed multiple times a day with the webcam or reported by the Washington VAAC, rose higher than 1.3 km above the summit crater and drifted mainly NW, W, SW, and S. Crater incandescence was visible nightly, and incandescent blocks were observed rolling 400 m down the flanks in all directions on most nights.

Sangay – Ecuador : IG reported that thermal anomalies, persistent at Sangay since July, suggested continuous emission of lava flows and hot pyroclastic material from summit crater vents. The SE drainage, which had been scoured and widened by persistent pyroclastic flows during August 2019 to March 2020, had only widened from about 600 m to about 650 m during March-October. An increased number of explosions and an inflationary trend were recorded during the previous few weeks. Strombolian activity began to dominate the eruptive style in July, though on 17 November the number of explosions increased to two per minute and remained at that level at least through 23 November. Most of the explosions were small and were recorded both by the seismic and acoustic networks. Though slight inflation began to be detected in June 2021 the trend was more pronounced in recent weeks. InSAR satellite data showed an inflationary trend of up to 5 cm per year all around the volcano except the E flank between 5 January 2020 and 13 November 2021. The sulfur dioxide emission rate had remained stable and low since June, with values less than 1,000 tons per day. Daily ash-and-gas plumes were identified by the Washington VAAC or in IG webcam views during 23-29 November. The plumes rose 970-2,100 m above the volcano and drifted NW, W, SW, and S. Daily thermal anomalies over the volcano were often visible in satellite data. Strombolian activity at summit vents and SE-descending lava flows were visible during 23-24 November. A new vent was possibly identified on the upper W flank. Two lahars were detected by the seismic network on 25 November.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that eruptive activity at Semisopochnoi’s North Cerberus crater continued during 24-30 November. Daily minor explosions were detected in seismic and infrasound data. Weather clouds obscured satellite and webcam views of the volcano on most days; small ash plumes rising no higher than 3 km (10,000 ft) a.s.l. were sometimes visible during breaks in the cloud cover but were likely emitted daily.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 19-26 November.

Stromboli – Aeolian Islands (Italy) : INGV reported that during 15-28 November activity at Stromboli was characterized by ongoing explosive activity from five vents in Area N (North Crater area) and four vents in Area C-S (South-Central Crater area). Explosions from Area N vents (N1 and N2) averaged 6-17 events per hour; explosions from two vents in the N1 vent ejected lapilli and bombs 80 m high and explosions at three N2 vents ejected material 80-150 m high. Spattering at N2 was sometimes intense. No explosions occurred at the S1 and C vents in Area C-S; explosions at the two S2 vents occurred at a rate of 4-9 per hour and ejected coarse material as high as 80 m. Drone footage acquired on 20 November captured two C-S vents ejecting shreds of lava and one emitting gas. A 60-m-line of fumaroles, oriented NNW, were situated on the Sciara del Fuoco, down-flank of Area N. During the morning of 21 November intense spattering occurred at a vent between N1 and N2 produced a rheomorphic lava flow, formed by the accumulated spatter, on the upper middle part of the Sciara del Fuoco. At 0751 on 25 November lava blocks originating from a hornito in the N2 area began rolling downslope. Within a few hours a lava flow was visible in the same area; blocks from the end of the flow descended the Sciara del Fuoco, reaching the coastline. The rate of lava effusion varied during 25-26 November; the flow had begun cooling by the evening of 27 November.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that during 22-29 November about 41 explosions at Suwanosejima’s Ontake Crater produced eruption plumes that rose as high as 2.7 km above the crater rim and ejected blocks 500-800 m from the crater. Crater incandescence was visible nightly.

Yasur – Vanuatu : The Vanuatu Meteorology and Geohazards Department (VMGD) and the Wellington VAAC reported that multiple gas-and-ash emissions at Yasur were visible in webcam images on 27 November rising 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifting W. Weather clouds prevented satellite observations of the emissions.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 24 November – 30 November 2021

Iliwerung – Lomblen Island (Indonesia) : A submarine eruption at Iliwerung was observed during 28-29 November, prompting PVMBG to raise the Alert Level to 2 (on a scale of 0-4). Residents reported seeing the sea surface, 30 m from the shore to the S, bubbling up to heights of less than 1 m beginning at 2152 on 28 November; the activity lasted about an hour. Eruptive activity at the sea surface was again observed at 0517 on 29 November. An observer described bubbling water and a plume rising about 100 m a few hours later, at 0829, though they noted that the activity was about 1 km S of the Hobal submarine vent (about 3 km E of the summit), the site of multiple eruptions since 1973. PVMBG warned residents to stay away from the coastline and the water nearest to the activity.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that during 18-20 and 25 November explosions at Karymsky generated ash plumes that rose as high as 6.5 km (21,300 ft) a.s.l. and drifted 370 km NE and NW. A thermal anomaly was visible in satellite images during 18-19 and 22 November.

Pinatubo – Luzon (Philippines) : PHIVOLCS reported that a weak phreatic explosion at Pinatubo was recorded during 1209-1213 on 30 November. The event was likely drive by shallow hydrothermal processes based on very low seismicity recorded during the previous few days, low diffuse carbon dioxide flux from the lake, and a notable infrasound signal. A plume mostly comprised of steam was seen rising above weather clouds within a few minutes of the end of the event. The Tokyo VAAC stated that the plume rose to 13.4 km (44,000 ft) a.s.l. and drifted W based on satellite data.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 17 November – 23 November 2021

Aira – Kyushu (Japan) : JMA reported that incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible at night during 15-22 November. Three eruptive events were recorded during 15-19 November. The sulfur dioxide emission rate was 700 tons per day on 16 November.

Dukono – Halmahera (Indonesia) : Based on satellite and wind model data, the Darwin VAAC reported that on 17 November ash plumes from Dukono rose to 2.1 km (7,000 ft) a.s.l. and drifted NE and ENE. Dense white plumes rose as high as 500 m and drifted NW, W, and SW during 18-23 November according to PVMBG.

Great Sitkin – Andreanof Islands (USA) : AVO reported that lava effusion at Great Sitkin had slowed or paused based on a 17 November satellite image that showed no advancement of the lava flows since 10 November. Seismicity remained elevated during 17-23 November and elevated surface temperatures were visible in occasionally clear satellite images. Steam emissions were sometimes visible in webcam images.

Katmai – United States : AVO reported that during 17-18 November strong winds in the vicinity of Katmai and the Valley of Ten Thousand Smokes blew unconsolidated ash SE over Shelikof Strait and Kodiak Island at an altitude up to 2.1 km (7,000 ft) a.s.l. The ash was originally deposited during the Novarupta eruption in 1912.

Kilauea – Hawaiian Islands (USA) : HVO reported that the summit eruption at Kilauea continued at a vent in the lower W wall of Halema`uma`u Crater. By 16 November the total volume of erupted lava was an estimated 30 million cubic meters, and the lake which had risen a total of 60 m since 29 September. During 17-23 November earthquake activity remained below background levels but volcanic tremor was elevated. Spattering and ponded lava within the vent were visible; lava entered the lake through the E part of the W wall cone, feeding an active area of the lake. Lava periodically oozed from the cooler, outer margins of the lake onto the lowest of the exposed down-dropped caldera floor blocks. The sulfur dioxide emission rate remained above background levels, and was 3,000-3,800 tonnes per day on 18 and 23 November.

Krysuvik-Trolladyngja – Iceland : Icelandic Meteorological Office (IMO) reported that no eruptive activity at the Krýsuvík-Trölladyngja volcanic system had been visible since 18 September. Small quantities of volcanic gases continued to be detected in the atmosphere. At the end of September, after the eruption had ceased, inflation of the Reykjanes Peninsula began to be detected and broadly correlated with an area that deflated during the eruption. The inflation was thought to be most likely caused by further intrusion of magma; the earthquake swarm detected S of Keilir in late September may be related to such an intrusion, though no deformation was detected at the surface during the swarm. IMO noted that such an influx of magma following an eruption was not uncommon, and that the inflation did not necessarily mean that another eruption was imminent.

La Palma – Spain : The eruption at La Palma continued during 17-23 November, characterized by Strombolian explosions and lava fountaining/jetting from multiple vents, advancing and sometimes branching lava flows, and daily ash emissions. Eruption details are based on official sources including daily PEVOLCA (Plan de Emergencias Volcánicas de Canarias) steering committee summaries. Volcanic tremor levels increased during 16-17 November then returned to low levels. Seismicity persisted at variable but elevated levels, with earthquake locations distributed at depths of 10-15 km and 30-40 km. The number of located earthquakes peaked at 230 during 17-18 November, which was the highest daily total recorded since the beginning of the eruption. Additionally, a M 5.1 earthquake was detected at 0208 on 19 November at a depth of 36 km; this event was the largest earthquake recorded since the swarm heralding the magmatic intrusion began on 11 September. Dozens of events were felt by residents during the week. Several vents in the main cone continued to effuse lava, eject tephra, and emit ash-and-gas plumes at varying intensities. Lava was transported W through pre-existing lava channels and tubes or descended over older flows and over new ground, increasing the area of the flow field, which was made up of overlapping flows numbered 1-11. Flows 1, 2, and 9 had merged and contributed lava to the main delta, which had grown more than 0.43 square kilometers by 23 November. In the evening of 18 November lava overflowed one of the craters in the main cone and increased the lava-flow rate; crater overflows were again visible on 21 November. Lava filled in some gaps between the N flows, numbers 4 and 7. During 17-18 November flow 5 advanced along the N base of Montaña de Todoque and along the S edge of flow 4 which had also advanced and widened. By 21 November flow 4 had merged with flow 7, the branch to the N. Flow 7 advanced W and by 1303 on 22 November lava reached the sea at La Viña Beach. Plumes ranging from white to dark gray rising from the new ocean entry prompted an air quality warning to be issued for about 3,000 people living in areas of San Borondón, Tazacorte, El Cardón, and Camino Los Palomares, all within about a 2 km radius to the N and NE. A ban on maritime activities near the entry also went into effect, though it was lifted the next morning. By 23 November the width of the flow field had grown to 3.3 km and lava covered an estimated 10.73 square kilometers. Sulfur dioxide emissions fluctuated at high levels between 900 and 32,000 tons per day, remaining at levels lower than the peak values of 50,000 tons per day recorded on 23 September. Suspended ash and high concentrations of volcanic gases triggered a few air-quality alerts mostly affecting the W part of the island; authorities warned residents of some affected areas (Los Llanos de Aridane, Tazacorte, El Paso, Puntagorda, and Tijarafe in particular) to stay indoors. High values of volcanic gases led to the evacuation of essential personnel working in plants in the exclusion zone during 16-17 November. After a lull in activity for a period of time on 17 November, Strombolian activity and ash emissions resumed later in the day and prompted a VONA the next day. Video posted at 1615 on 18 November showed jetting lava and billowing ash plumes containing some lightning flashes. Sometimes dense and billowing ash-and-gas plumes rose 2-3.7 km (6,600-12,100 ft) a.s.l. and drifted NE, E, ESE, and SW during the rest of the week. The 20 November PEVOLCA reported that the total volume of emitted tephra during the eruption had surpassed 10 million cubic meters. Ash deposits on runways and unfavorable flying conditions disrupted flights at La Palma airport during 21-23 November.

Lewotolok – Lembata Island (Indonesia) : PVMBG reported that the eruption at Lewotolok continued during 17-23 November. White-and-gray plumes that were sometimes dense rose as high as 2 km above the summit. Incandescent material was ejected 200 m E from the vent during 19-20 November. Crater incandescence was visible during 22-23 November.

Merapi – Central Java (Indonesia) : BPPTKG reported no notable morphological changes to Merapi’s SW lava dome, located just below the SW rim, or the dome in the summit crater during 12-18 November. The estimated dome volumes remained stable at 1.61 million cubic meters for the SW dome and almost 2.93 million cubic meters for the summit dome. As many as 212 lava avalanches traveled a maximum of 2 km SW. One pyroclastic flow traveled 1.8 km SW on 13 November.

Nevados de Chillan – Chile : SERNAGEOMIN reported continuing explosive and effusive activity at Nevados de Chillán’s Nicanor Crater during 1-15 November. Explosions generated both plumes with moderate ash content and white steam-rich plumes that rose as high as 2 km above the crater rim. Explosions occasionally ejected incandescent material onto the N side of the crater and the N flank. A new dome, which had emerged around 28 October at the L7 vent, was partially destroyed by explosions on 8 November, and then regrew to 80 m long and 55 m wide. Pyroclastic flows descended the NE flank, traveling as far as 700 m on 8 and 10 November. The L7 lava flow, between the inactive L5 and L6 flows, slowly advanced and was 930 m long; a NE branch of L7 had not advanced since 14 October, though SE and E branches formed on 9 and 14 November, respectively. A second active flow, L8, had not lengthened past 385 m. Sulfur dioxide emissions averaged 300 tons per day, peaking at 462 tons per day on 14 November, and were lower than rates recorded during the last half of September.

Pavlof – United States : AVO reported that the eruption at Pavlof continued during 14-23 November and was focused at a vent on the upper NE flank. Seismicity remained elevated and signals were periodically recorded that were likely explosions. Lava fountaining began on 14 November and had built a small, unstable cone. Hot debris from the cone traveled a few hundred meters down the flanks, melting snow and ice that resulted in narrow lahars which traveled several kilometers down the flanks. Elevated surface temperatures were observed in satellite data at least through 23 November, suggesting that the lava fountaining continued.

Popocatepetl – Mexico : CENAPRED reported that each day during 16-23 November there were 9-29 steam-and-gas emissions from Popocatépetl that drifted NW, NE, and E. At 1714 on 19 November an explosion generated an ash plume that rose 2 km above the crater rim and drifted NE. A minor explosion at 0230 on 21 November generated an ash plume that rose 600 m and drifted NW, and at 0136 the next morning another small explosion produced an ash plume that rose 800 m and drifted NE.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported a daily average of 74 explosions at Sabancaya during 15-21 November. Gas-and-ash plumes rose as high as 2 km above the summit and drifted NE, S, SW, and W. Eight thermal anomalies originating from the lava dome in the summit crater were identified in satellite data. Minor inflation continued to be detected near Hualca Hualca (4 km N).

Semeru – Eastern Java (Indonesia) : PVMBG reported that gray-and-white emissions rose 200-700 m above Semeru’s summit and drifted SW, N, and E during 16-23 November. The emissions were visible almost daily; weather clouds occasionally prevented visual observations of the summit. 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.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that eruptive activity at Semisopochnoi’s North Cerberus crater continued during 17-23 November. Daily minor explosions were detected in seismic and infrasound data. Small ash plumes rising no higher than 3 km (10,000 ft) a.s.l. likely continued to be emitted, though weather clouds obscured satellite and webcam views of the volcano on most days.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 12-19 November.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that plumes from Suwanosejima’s Ontake Crater rose 180-200 m above the crater rim during 15-22 November. Large blocks were ejected 300 m from the crater and were deposited in a ballistic pattern during 15-19 November, and ashfall was reported in Toshima village (4 km SSW).

Taal – Luzon (Philippines) : PHIVOLCS reported that unrest at Taal continued during 17-23 November. Sulfur dioxide emissions continued to be elevated, averaging 6,643-12,168 tonnes/day. Upwelling hot volcanic fluids were visible in the crater lake, and daily gas-and-steam plumes rose 1-3 km above the lake and drifted WNW, WSW, and SW. Low-level background tremor persisted along with 5-30 volcanic earthquakes per day, 2-4 low-frequency volcanic earthquakes per day, and 1-23 daily episodes of volcanic tremor, each lasting 1-5 minutes. One hybrid earthquake was recorded during 19-20 November and three were detected during 22-23 November. No earthquakes were recorded for a period during 18-19 November. Three short (1-5 minutes) phreatomagmatic bursts were recorded at 0811, 0817, and 0834 on 22 November. The events generated plumes that rose 200-1,500 m based on thermal camera images. PHIVOLCS stated that the events were likely driven by fracturing and gas release from magma beneath the Taal Volcano Island.

Vulcano – Aeolian Islands (Italy) : According to an order issued by the Municipality of Lipari that went into effect on 22 November, residents within three high-risk zones (with an exception for the Lentia village) on Vulcano were not allowed to stay overnight in their homes between the hours of 2300-0600 due to an increase in carbon dioxide emissions in area to the N of La Fossa Crater. Residents in a lower-risk zone were allowed to stay in their homes but not sleep on the first floor. In addition, non-residents were banned from visiting the island for 30 days except for essential workers.

Whakaari/White Island – North Island (New Zealand) : GeoNet reported results from an 18 November overflight of Whakaari/White Island, noting a decrease in gas emissions and the lake level. Gas measurements showed that sulfur dioxide emissions had decreased from 681 tons per day recorded on 2 November to 484 tons per day. Additionally, both carbon dioxide and hydrogen sulfide decreased from 2712 to 1416 tons per day and from 38 to 19 tons per day, respectively. The gas data suggested that molten material at depth continued to degas. Temperatures in the main vent area were 243-264 degrees Celsius, similar to the range (202-264 degrees Celsius) measured both in September and earlier in November. Very minor ash emissions were visible and deposits only extended around the active vents. A new vent was observed, located S of the main vent and near the base of the 2019 landslide area. Deposits around the new vent suggested that it formed by an energetic, steam-driven ejection of mud.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 17 November – 23 November 2021

Asosan – Kyushu (Japan) : JMA lowered the Alert Level for Asosan to 2 (on a scale of 1-5) at 1100 on 18 November and decreased the restricted area to a radius of 1 km, noting that no eruptions had been recorded since the 21 October eruption. The sulfur dioxide emission rate remained elevated in November and was 2,100 tons per day on 16 November. The amplitudes of volcanic microtremors fluctuated for a period after the eruption, though they were generally small beginning on 1 November.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that during 11-13 and 18 November explosions at Karymsky generated ash plumes that rose as high as 8 km (26,200 ft) a.s.l. and drifted 400 km NE and NW. A thermal anomaly was visible in satellite images during 14-18 November.

Turrialba – Costa Rica : OVSICORI-UNA reported that at 0624 on 23 November a one-minute-long eruption at Turrialba produced a plume that rose 500 m above the crater rim and drifted SW. Another small eruption was recorded on 7 November.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 10 November – 16 November 2021

Aira – Kyushu (Japan) : JMA reported that incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible at night during 8-15 November. Very small eruptions were recorded.

Ebeko – Paramushir Island (Russia) : According to volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, an explosion each day during 5-9 November produced ash plumes that rose as high as 2.3 km (7,500 ft) a.s.l. and drifted SE and E.

Fernandina – Ecuador : IG reported that slow deformation at Fernandina has been recorded over the previous 18 months. InSAR data showed that inflation was occurring at a rate of about 400 mm/year in the summit caldera and on the NE flank, while deflation was occurring at a rate of about 100-400 mm/year in areas on the upper W and SW flanks. On 13 October the areas of deflation changed to inflation and the rate of deformation in the caldera increased. On 17 November IG noted that fumarolic activity in the summit crater was visible during the previous few days and may have been related to a small episode of tremor on 16 November. IG also noted that periodic fumarolic activity and small episodes of tremor are common at Fernandina without an eruption.

Fukutoku-Oka-no-Ba – Volcano Islands (Japan) : The Japan Coast Guard reported that during an 11 November overflight of Fukutoku-Oka-no-Ba, observers noted that the size of the W island was mainly unchanged. White fumarolic plumes rose from the N end of the island and bubbling was seen on the ocean surface near the N end.

Great Sitkin – Andreanof Islands (USA) ; AVO reported that lava effusion at Great Sitkin continued during 10-16 November. Elevated surface temperatures were visible in clear satellite images during 11 and 15-16 November. Two days later effusion was confirmed in satellite images; the N lava flow had not progressed but the W and S flank flows had advanced to 680 and 650 m, respectively.

Ibu – Halmahera (Indonesia) : PVMBG reported that during 10-11 and 14-16 November gray-and-white ash plumes from Ibu rose 200-800 m above the summit. During 10-11 November the ash plumes drifted S and W, causing minor ashfall in villages to the W.

Kadovar – Papua New Guinea : Based on satellite and wind model data, the Darwin VAAC reported that on 9 November an ash plume from Kadovar rose to an altitude of 1.5 km (5,000 ft) a.s.l.

Kilauea – Hawaiian Islands (USA) : HVO reported that the summit eruption at Kilauea continued at a vent in the lower W wall of Halema`uma`u Crater. By 9 November the total volume of erupted lava was an estimated 27 million cubic meters. The sulfur dioxide emission rate was 2,600 tonnes per day on 9 November. Spatter and ponded lava in the vent were visible during 9-16 November; lava entered the lake through a short channel in the E part of the W wall cone, feeding the lake which had risen 60 m since 29 September. The active area of the lava lake had increased during the week.

La Palma – Spain : The eruption at La Palma continued during 10-16 November, characterized by Strombolian explosions and lava fountaining from multiple vents, advancing and sometimes branching lava flows, and daily ash emissions. Eruption details are based on official sources including daily PEVOLCA (Plan de Emergencias Volcánicas de Canarias) steering committee summaries. Volcanic tremor levels continued to be low. Seismicity at intermediate depths of 10-15 km remained low compared to previous weeks. The number and magnitude of deeper events, 20-38 km deep, increased during 9-11 with the highest number of deeper events recorded since the beginning of the eruption; the rate of deeper events decreased during 11-12 November. Two M 5 earthquakes were the largest events recorded during the week, occurring at 0447 on 11 November at a depth of 30 km and at 0756 on 13 November at a depth of 38 km. Several vents in the main cone continued to effuse lava, eject tephra, and emit ash-and-gas plumes. The activity levels varied in intensity, though decreased overall during the week. By 10 November the highest point of the main cone was 1,130 m a.s.l. Lava continued to flow west through pre-existing lava channels and tubes, over older flows, and occasionally formed new branches. Occasional short-lived overflows of lava ponds occurred at the main crater vents. The flow field was made up of overlapping flows numbered 1-11. Lava filled in some gaps between the N flows, numbers 4 and 7, though lava-flow advancement was mainly focused at and near the ocean entries, with lava feeding flows 1, 2, and 9. The first flow, number 1, had previously reached the sea, and flow 9 had stalled before reaching the coast. Flow number 2 (in between 1 and 9) had reached the sea at Los Guirres Beach on 9 November, and sent a new branch N that entered the ocean at 0144 on 10 November. Flow 2 continued to advance during the week, filling in gaps between flows 1 and 9, and adding to the new lava delta laterally. Areas of high turbidity in the water column as far as 1 km from the lava front were caused by underwater lava advancement. By 16 November the width of the flow field had grown to 3.2 km. Sulfur dioxide emissions fluctuated at high levels between 7,000 and 43,000 tons per day on most days, but was as low as 2,000-4,000 tons per day on 13 and 15 November. Sometimes dense and billowing ash-and-gas plumes rose 1.8-3.1 km (5,900-10,200 ft) a.s.l. and drifted in multiple directions. Ash emissions intensified on 14 November. Clean-up of ash from streets and homes was conducted by both authorities and residents. According to a news report a resident that was granted permission to enter the exclusion zone to clean ash off of his roof died in the neighborhood of Corazoncillo of unknown causes. Fresh ash emissions from the volcano, and ash resuspended by people and vehicle movements, triggered a few air-quality alerts issued during 14-16 November; authorities warned residents of some affected areas (Los Llanos de Aridane, Tazacorte, El Paso, Puntagorda, and Tijarafe) to stay indoors. On 16 November ash drifted W and SW and caused some flight disruptions at the La Palma airport.

Merapi – Central Java (Indonesia) : BPPTKG reported no notable morphological changes to Merapi’s SW lava dome, located just below the SW rim, or in the summit crater during 5-11 November. As many as 123 lava avalanches traveled a maximum of 2 km SW. Two pyroclastic flows traveled 1.5-2 km SW.

Pavlof – United States : AVO reported that the eruption at Pavlof continued during 10-16 November and was focused at a vent on the upper NE flank. Seismicity remained elevated. Pilots observed steam plumes rising to 4.3 km (14,000 ft) a.s.l.; steam plumes were also visible the next day. On 11 November a narrow 2-km-long lahar deposit on the SE flank was identified in satellite images. The lahar was likely generated by the interaction of lava and snow on the upper flank. Strongly elevated surface temperatures visible in satellite images during 10-15 November were indicative of lava effusion and possibly fountaining. Several explosions were recorded during 12-14 November.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that eruptive activity at Semisopochnoi’s North Cerberus crater continued during 10-16 November. Daily minor explosions were detected in seismic and infrasound data. Daily ash plumes were visible in webcam and satellite data rising to 1.5-3.7 (5,000-12,000 ft) a.s.l., drifting NE, E, SE, and S, and dissipated quickly. Weather clouds sometimes obscured views. Ash plumes were typically dissipating within 50 km of the volcano. Minor ashfall on the island was sometimes visible.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 5-12 November.

Stromboli – Aeolian Islands (Italy) : INGV reported that during 8-14 November activity at Stromboli was characterized by ongoing explosive activity from five vents in Area N (North Crater area) and four vents in Area C-S (South-Central Crater area). Sometimes weather conditions prevented visual confirmation with webcams. Explosions from two vents in the N1 vent (Area N) ejected lapilli and bombs 80 m high. Short periods of spattering at the vent overlooking the Sciara del Fuoco was sometimes observed and intensified on 8 and 12 November. Explosions at three N2 vents (Area N) averaged 10-15 events per hour and ejected material 80-150 m high. Sometimes intense spattering was recorded during 8-9 and 14 November. No explosions occurred at S1 and C vents in Area C-S; explosions at the two S2 vents occurred at a rate of 6-7 per hour and ejected coarse material as high as 80 m high.

Taal – Luzon (Philippines) : Three short (1-3 minutes) phreatomagmatic bursts at Taal were recorded at 2339 on 15 November, and at both 0146 and 0254 on 17 November. The first generated a plume that rose 2.4 km and drifted SW and the next two events generated plumes that rose 400-500 m based on thermal camera images. PHIVOLCS stated that the events were likely driven by fracturing and gas release from magma beneath the Taal Volcano Island. Sulfur dioxide emissions averaged 9,448-12,516 tonnes/day during 10-16 November. Upwelling hot volcanic fluids were visible in the crater lake, and daily gas-and-steam plumes rose 0.7-1.5 km above the lake and drifted mainly SW. Low-level background tremor continued to be recorded. During 9-12 November the seismic network recorded 135-223 volcanic earthquakes per day, and as many as 72 low-frequency volcanic earthquakes per day, and 70-180 daily episodes of volcanic tremor, each lasting 1-3 minutes. Three hybrid earthquakes were recorded during 9-10 November. No earthquakes were detected during 12-13 November. Seismicity then increased during 14-16 November with a few periods of tremor (1-3 minutes long), 9-10 daily volcanic earthquakes, and 3-4 daily low-frequency volcanic earthquakes.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 10 November – 16 November 2021

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that during 8-12 November explosions at Karymsky generated ash plumes that rose as high as 5.5 km (18,000 ft) a.s.l. and drifted 300 km E and SE. A thermal anomaly was visible in satellite images.

Turrialba – Costa Rica : OVSICORI-UNA reported that on 11 November a small area of incandescence was visible on the internal SW wall of Turrialba’s summit vent. Vigorous degassing from the vent was recorded.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 3 November – 9 November 2021

Aira – Kyushu (Japan) : JMA reported that incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible at night during 1-8 November. An eruption at 2225 on 2 November produced a plume that rose 1.1 km above the crater rim and drifted SW. The sulfur dioxide emission rate was 1,000 tons per day on 4 November. Very small eruptions were detected during 5-8 November.

Ebeko – Paramushir Island (Russia) : According to volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, an explosion on 2 November produced an ash plume that rose as high as 2.6 km (8,500 ft) a.s.l. and drifted SE.

Great Sitkin – Andreanof Islands (USA) : AVO reported that lava flows at Great Sitkin were approximately 680 m long on the W flank, 560 m long on the S flank, and 90 m long on the N flank by 30 October based on satellite images. Lava effusion probably continued during 3-9 November, though weather clouds prevented visual confirmation. Elevated surface temperatures were occasionally detected in satellite images during 2-3 and 5-6 November. Seismicity was low overall, though slightly increased during 6-7 November.

Kadovar – Papua New Guinea : Based on satellite and wind model data, the Darwin VAAC reported that on 3 and 5 November 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 the summit eruption at Kilauea continued during 2-9 November at a vent in the lower W wall of Halema`uma`u Crater. Lava entered the lake through a short channel in the E part of the W wall cone, feeding the lake which had risen 56 m since 29 September; the channel was covered with a cooled crust by 3 November. Lava began to flow over the E edge of the lava lake, which is perched above the crater floor, by 4 November. The sulfur dioxide emission rate was 1,700-2,900 tonnes per day during 3-5 November and 250 tonnes per day during 7-8 November. Low roiling and bursts of spatter from the small perched pond in the W vent cone were observed; activity at the vent had decreased by 8 November, along with the area of active lava at the surface of the main lava lake, then returned to higher levels by 9 November.

La Palma – Spain : The eruption at La Palma continued during 2-9 November, characterized by Strombolian explosions and lava fountaining from multiple vents, advancing and branching lava flows, and daily ash emissions. Eruption details are based on official sources including PEVOLCA (Plan de Emergencias Volcánicas de Canarias) steering committee daily summaries. Volcanic tremor levels decreased around noon on 2 November and again during 4-5 November, and remained at low levels through 9 November. Most earthquakes were located 10-15 km deep (though some were as deep as 38 km); dozens of events were felt by local residents and some were felt across the entire island. At 0824 on 3 November a M 4.8 located 36 km deep was followed three seconds later by a M 5 at 35 km depth; they were perceived by residents as one long event; the M 5 was the largest earthquake of the week. Two other notable earthquakes occurred consecutively; a M 4.6 at a depth of 37 km at 1807 on 7 November was followed eight seconds later by a M 4.5 at 38 km depth. Some of the larger earthquakes were felt across La Palma Island, as well as in some areas of La Gomera and Tenerife islands. In general, decreases were observed in the levels of seismicity, tremor, deformation, and sulfur dioxide emissions, though by 9 November the data continued to fluctuate with no consistent trends. The vents in the main cone continued to effuse lava, eject tephra, sometimes producing dense billowing ash-and-gas plumes that rose 2.5-3.5 km (8,200-11,500 ft) a.s.l. and drifted WSW, SW, and SSE. Several vents in the main cone were active, though the activity levels varied in intensity throughout the week. Weather conditions and large amounts of emitted ash resulted in air quality alerts issued daily by authorities as they warned residents of some affected areas (Los Llanos de Aridane, Tazacorte, El Paso, Puntagorda, and Tijarafe) to stay indoors; air quality was “extremely unfavorable” on most days then upgraded to “unfavorable” on 9 November. Sulfur dioxide emissions fluctuated at high levels between 9,000 and 31,300 tons per day and showed an overall decrease. On 5 November photos showed sulfur deposits on the E flank on the main cone and in other areas near vents emitting volcanic gases. Lava continued to flow west through pre-existing lava channels and tubes, over older flows, and occasionally formed new branches. The flows were numbered 1-11. Flow 11 originated at the end of October along the upper central part of the S margin of the flow field, N of Montaña Cogote; by 3 November it was 100 m from the LP-211 road and on 6 November the advancement rate increased. Lava number 2, located between the main flow, number 1, that had reached the ocean on 21 September and flow number 9 which had previously branched off of the main flow to the S, advanced during 8-9 November. The flow reached the sea cliff at Los Guirres Beach and then entered the ocean at 0245 on 9 November. Overall, the flow field covered an estimated 9.84 square kilometers by 8 November.

Merapi – Central Java (Indonesia) : BPPTKG reported no morphological changes to Merapi’s SW lava dome, located just below the SW rim, and in the summit crater during 29 October-4 November. As many as 106 lava avalanches traveled a maximum of 2 km SW. One pyroclastic flow traveled 2 km SW.

Nevado del Ruiz – Colombia : On 9 November Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that intense seismicity at Nevado del Ruiz had been recorded for the previous few weeks. Deformation data indicated minor changes. Low-temperature thermal anomalies were visible in satellite images during the previous week. Gas-and-steam emissions were sometimes visible in satellite data and webcam images rising as high as 1.9 km above the summit and drifting NE and E. These emissions sometimes contained ash; during 0735-0815 on 3 November an ash plume rose 1.4 km above the summit. Ash emissions on 7 November drifted W and NW, causing ashfall in Manizales and Villamar?a, both 25 km NW. The La Nubia airport temporarily suspended operations.

Pavlof – United States : AVO reported that the eruption at Pavlof continued during 3-9 November and was focused at a vent on the upper NE flank. Seismicity remained elevated; several small explosions and discontinuous tremor were recorded during 5-8 November with increased frequency compared to the previous week. The explosions likely produced small, low-level ash plumes, though weather clouds often prevented confirmation by satellite and webcam images. Elevated surface temperatures were visible in satellite images overnight during 7-8 November, coincident with the emplacement of a 30-m-long lava flow. Small diffuse ash plumes were visible in webcam images and dissipated quickly. Elevated surface temperatures remained visible through 9 November.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that eruptive activity at Semisopochnoi’s North Cerberus crater continued during 2-9 November. Daily tremor and minor explosions were detected in seismic and infrasound data. Several small low-level ash plumes were visible in webcam data rising to an estimated altitude of 1.5 (5,000 ft) a.s.l. during 2-3 November. Weather clouds obscured views during 4-7 November with the top of the cloud deck varying at altitudes of 3-6.1 km (10,000-20,000 ft) a.s.l.; ash plumes likely continued to be emitted though none rose above the cloud deck. Ash plumes were typically dissipating within 50 km of the volcano.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 29 October-5 November.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that seven explosions at Suwanosejima’s Ontake Crater were recorded during 1-8 November. The explosions produced ash plumes that rose as high as 2 km above the crater rim and ejected material 300-600 m from the carter. Ashfall was reported in Toshima village (4 km SSW) during 1-5 November.

Taal – Luzon (Philippines) : PHIVOLCS reported that a series of volcanic earthquakes at Taal began at 0347 on 3 November and lasted for two minutes based on the seismic data; the events were felt at Intensity I in Banyaga, Agoncillo, and Batangas, and the largest event was a local M 2.9. The events were accompanied by a series of four short-lived plumes that rose less than 1 km above the lake. The characteristics of the seismic signals were similar to the phreatic bursts recorded in July. Upwelling hot volcanic fluids were visible in the crater lake during 3-9 November, and gas-and-steam plumes rose 0.9-1.8 km above the lake and drifted mainly SW. Sulfur dioxide emissions averaged 4,877-19,463 tonnes/day. Low-level background tremor continued along with as many as 111 volcanic earthquakes per day during 2-3 and 5-9 November and as many as 85 low-frequency volcanic earthquakes per day during 2-3 and 7-8 November. There were also 6-40 daily episodes of volcanic tremor, each lasting between 1 and 19 minutes.

Telica – Nicaragua : INETER reported that at 1650 on 28 October a small explosion from Telica produced an ash plume that rose 150 m above the crater rim and deposited ash on the NW flank. The event was followed by a small series of low-energy explosions that generated ash plumes that rose 300 m high and drifted N and NE. Minor ashfall was reported in Aguas Frías.

Villarrica – Chile : According to the Buenos Aires VAAC an ash plume from Villarrica rose to km (11,000 ft) a.s.l. and drifted SE on 6 November.

Whakaari/White Island – North Island (New Zealand) : On 9 November GeoNet reported results from a recent overflight of Whakaari/White Island. Gas measurements showed that sulfur dioxide emissions had increased from 267 tons per day recorded on 14 October to 681 tonnes per day. Additionally, carbon dioxide increased from 757 to 2712 tonnes per day and hydrogen sulfide increased from 10 to 38 tonnes per day. The gas data suggested that a pulse of gas was rising from molten material at depth. Temperatures in the main vent area were as high as 252 degrees Celsius, similar to temperatures first measured in September and onward. Very minor ash emissions were visible and deposits only extended around the active vents. The lake had slightly deepened from recent rainfall.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 3 November – 9 November 2021

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that during 29 October-2 November explosions at Karymsky generated ash plumes that rose as high as 4 km (13,100 ft) a.s.l. and drifted 135 km E and SE. According to the Tokyo VAAC ash plumes rose as high as 7.9 km (26,000 ft) a.s.l. on 3 November and drifted SE and E. A powerful explosive eruption on 4 November generated notable ash plumes described in a series of VONAs issued by KVERT and volcanic ash advisories (VAAs) issued by the Tokyo and Anchorage VAACs. On 4 November ash plumes rose 3-9.5 km (10,000-31,200 ft) a.s.l. and drifted E. Satellite images acquired at 1750 showed two large ash clouds, one was 400 x 560 km in extent and had drifted 1,090 km E and the second was 80 x 280 km and had drifted 460 km SE. On 5 November ash plumes rose 3-5.5 km (10,000-18,000 ft) a.s.l. and drifted E and NE. Additional explosions at 1540 on 6 November generated ash plumes that rose 7.5-8 km (24,600-26,200 ft) a.s.l. and drifted ENE, prompting KVERT to raise the Aviation Color Code to Red (the highest level on a four-color scale). Observers on Medny and Bering islands reported ashfall. Activity waned, but at 1305 on 7 November more ash plumes rose to 4-4.6 km (13,100-15,000 ft) a.s.l. and drifted 110 km NNE.

Krakatau – Indonesia : PVMBG reported that during periods of clear weather during 2-9 November white plumes from Anak Krakatau were visible rising as high as 100 m above the summit. White-to-gray plumes were seen in webcam images during 6-7 November rising 150 m and crater incandescence was visible three times.

Manam – Papua New Guinea : The Darwin VAAC reported that on 3 and 8 November ash plumes from Manam rose to 1.8 km (6,000 ft) a.s.l. and drifted NW and W based on satellite data and weather models.

Turrialba – Costa Rica : OVSICORI-UNA reported that a one-minute-long eruption at Turrialba was recorded at 0646 on 3 November and produced a plume that rose 200 m above the crater rim and drifted W. Another small eruption was recorded on 7 November.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 27 October – 2 November 2021

Aira – Kyushu (Japan) : JMA reported that incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible at night during 25 October-1 November. Two very small eruptions were detected on 28 and 31 October.

Ebeko – Paramushir Island (Russia) : On 31 October an explosion at Ebeko produced an ash plume that rose to 1.8 km (5,900 ft) a.s.l. and drifted 5 km NE.

Fuego – Guatemala : INSIVUMEH reported that 3-14 explosions per hour were recorded at Fuego during 26 October-2 November, generating ash plumes as high as 1.1 km above the crater rim and shock waves felt in communities around the volcano. Ash plumes mostly drifted as far as 50 km SW, W, and NW and 20 km N and S, causing almost daily ashfall in several areas downwind, including Morelia (9 km SW), Panimaché I and II (8 km SW), Santa Sofía (12 km SW), Yucales (12 km SW), El Porvenir (8 km ENE), Finca Palo Verde, La Rochela, Sangre de Cristo (8 km WSW), and San Pedro Yepocapa (8 km NW). Block avalanches descended the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), and Las Lajas (SE) drainages, often reaching vegetated areas. Explosions ejected incandescent material 100-400 m above the summit each day.

Fukutoku-Oka-no-Ba – Volcano Islands (Japan) : The Japan Coast Guard reported that floating pumice from the mid-August Fukutoku-Oka-no-Ba eruption had arrived at coastlines more than 1,000 kilometers away in early October. The pumice first arrived at Kitadaito Island (1,035 km W) on 8 October. In late October pumice circled Okinawa and Maejima islands (1,422 km W) and several ports in the Kagoshima prefecture (1,322 NW). The pumice damaged hundreds of boats and ships, clogged harbors, and impacted the fishing and tourism industries in several areas. Several local governments began the process of removing the pumice from the water.

Great Sitkin – Andreanof Islands (USA) : AVO reported that lava flows on Great Sitkin’s S and W flanks were 600 m long by 27 October based on satellite images, and lava effusion likely continued during 27 October-2 November. Seismicity remained elevated and was characterized by small earthquakes consistent with ongoing lava flows. Elevated surface temperatures were occasionally detected in satellite images.

Ibu – Halmahera (Indonesia) : PVMBG reported that during 26 October-2 November gray-and-white ash plumes from Ibu rose 200-800 m above the summit and drifted N, W, and S. There were at least 151 eruptive events observed during 28-30 October.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that during 22 and 26-28 October explosions at Karymsky generated ash plumes that rose as high as 4 km (13,100 ft) a.s.l. and drifted 65 km E and SE. A thermal anomaly was visible on 22 and 28 October.

La Palma – Spain : The eruption at La Palma continued during 26 October-2 November, characterized by Strombolian explosions, lava fountaining from multiple vents, advancing and branching lava flows, and daily ash emissions. Eruption details are based on official sources including PEVOLCA (Plan de Emergencias Volcánicas de Canarias) steering committee summaries issued daily. Seismicity remained elevated, with most earthquakes located 10-15 km deep (though some were as deep as 38 km); dozens of events were felt by local residents and some were felt across the entire island. A M 5 earthquake was recorded at 0724 on 30 October at a depth of 35 km and was the largest earthquake recorded since the beginning of the eruption. A second M 5 earthquake was recorded at 1852 on 1 November and had a depth of 38 km. Both of these events, as well as some of the other notable earthquakes, were felt across La Palma Island and in some areas of La Gomera and Tenerife islands. The vents in the main cone continued to effuse lava, eject tephra, and produce sometimes dense and billowing ash-and-gas plumes that rose 2.2-5 km (7,200-16,400 ft) a.s.l. Several vents in the main cone were active, though the activity levels varied in intensity throughout the week. A small collapse of the upper part of the main cone on 26 October caused lava to flow W over previous flows that filled in some small gaps where they had not previously covered. Beginning around noon on 29 October a series of intense and audible explosions occurred for several hours, generating a large amount of ash that was distributed across the valley. The tallest ash plumes were observed during 30-31 October. Audible explosions and significant ash emissions continued intermittently through 2 November, with ashfall affecting the entire W and NW parts of the island. Authorities issued multiple air quality alerts warning residents of some affected areas (Los Llanos de Aridane in particular), to stay indoors and, if going outside, to wear a filtering mask. For a period of time on 31 October the larger explosions were accompanied by shock waves and concurrently, the effusion rate at the NW flank vent notably increased. Sulfur dioxide emissions fluctuated at high levels between 4,990 and 22,000 tons per day during 27 October-2 November and showed an overall downward trend during the last week in October; no estimates were made on 29 October due to technical difficulties. Lava effused at a high rate from a vent on the NW flank of the main cone, flowing through pre-existing lava channels and tubes, and occasionally breaking out and forming new flows. The lava-flow field was characterized by three main areas: the initial main flow that traveled W, flowing around the S part of Montaña de Todoque, toward the sea and creating a lava delta, a flow that had branched off of the main flow to the S, and the flows that traveled W along the N margins of the main flow. Lava flows sometimes overflowed their channels, forming ephemeral flows that spread laterally, descended short distances, and were also transported downslope in lava tubes. The initial flow that reached the sea and formed the delta was not notably fed and was 30 m thick in some areas. The lava flows that had advanced W along the S side of Montaña de La Laguna was 86 m from the coast of Tazacorte, near the beach of El Perdido. The southern flow had advanced at a low rate and by 28 October was 400 m from the sea by 27 October. Lava that travelled SW over older flows emplaced along the S margins of the flow field overflowed the channel, bifurcated, and quickly advanced 1.5 km W and SW over new ground during 28-30 October. This lava flow continued to advance and by 2 November it was 150 m from the LP-211 road, though the advancement rate had slowed considerably to 1 meter per hour. Overall, the flow field widened to 3.1 km, with most of the expansion occurring along the S margins, and covered an estimated 9.77 square kilometers by 2 November.

Lewotolok – Lembata Island (Indonesia) : PVMBG reported that the eruption at Lewotolok continued during 26 October-2 November. White-and-gray plumes rose as high as 1 km above the summit and drifted in multiple directions. Rumbling and banging noises were heard daily. Crater incandescence was visible on 28 October and incandescent material was ejected 100-200 m from the vent on 29 October and 1 November.

Merapi – Central Java (Indonesia) : BPPTKG reported no morphological changes to Merapi’s SW lava dome, located just below the SW rim, and in the summit crater during 22-28 October. As many as 30 lava avalanches traveled a maximum of 1.8 km SW.

Pavlof – United States : AVO reported that the eruption at Pavlof continued during 27 October-2 November and was focused at a vent on the upper SE flank, near the location of the 2007 vent. Seismicity remained elevated with tremor and daily small explosion signals. The explosions likely produced low-level ash plumes that rose no higher than 3 km (10,000 ft) a.s.l., though weather clouds often prevented confirmation by satellite and webcam images. Elevated surface temperatures were visible in satellite images during 25-26 October. A small plume and discolored snow at the summit were visible in mostly clear satellite images during 27-28 October. Slightly elevated temperatures were identified in satellite images during 31 October-2 November. Minor steaming at the vent was seen in webcam images on 1 November, as well as a small ash plume that rose to a low height and dissipated quickly.

Popocatepetl – Mexico : CENAPRED reported that each day during 26 October-2 November there were 9-118 steam-and-gas emissions from Popocatépetl. Some of the emissions contained ash during 26-28 October and 31 October-1 November.

Reventador – Ecuador : IG reported that a high level of activity continued to be recorded at Reventador during 26 October-2 November; cloudy weather conditions sometimes prevented webcam and satellite views. Gas-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, N, and NE. Ashfall was reported in El Reventador village on 27 October. At night during 26 and 30-31 October and 1 November incandescent blocks were observed rolling 500-700 m down the flanks in all directions.

Sangay – Ecuador : IG reported a high level of activity at Sangay during 27 October-2 November. Seismicity was characterized by 120-175 daily explosions, long-period earthquakes, lahar events, and signals indicating emissions. Weather clouds and rain often prevented visual and webcam observations of the volcano, though almost daily ash-and-gas plumes were identified in satellite images by the Washington VAAC or in webcam views; plumes rose 570-2,000 m above the volcano and drifted N, NW, W, and SW. Thermal anomalies over the volcano were often visible in satellite data. Incandescent material was observed descending the SE flank on 31 October.

Santa Maria – Guatemala : INSIVUMEH reported that almost daily ash plumes from Santa Maria’s Santiaguito lava-dome complex rose 500-900 m during 26 October-2 November, depositing ash on the flanks and in Monte Claro during 1-2 November. Extrusion continued at the summit dome complex and generated block-and-ash flows that traveled down the dome’s flanks in several directions, often reaching the base. Incandescence from the crater was visible at night.

Semeru – Eastern Java (Indonesia) : PVMBG reported that on 31 October two ash plumes from Semeru were observed rising 400-500 m above the summit and drifting SW. Eruptive activity was recorded the next day, though plumes were not visually observed.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that eruptive activity at Semisopochnoi’s North Cerberus crater continued during 26 October-2 November. Daily tremor and minor explosions were detected in seismic and infrasound data. Although weather clouds often prevented webcam and satellite views, intermittent, low-level ash emissions were visible during clear views, rising as high as 3.7 km (12,000 ft) a.s.l. and dissipating quickly. Sulfur dioxide emissions were detected during 26-27 and 30-31 October.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 22-29 October.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that an explosion at 1317 on 26 October at Suwanosejima’s Ontake Crater produced an eruption plume that rose as high as 3.3 km above the crater rim and ejected material 1.9 km away from the crater. Ashfall was reported in Toshima village (4 km SSW). No explosions were recorded during 29 October-1 November, though eruption plumes rose as high as 2.4 km and tephra was ejected 400 m from crater.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 27 October – 2 November 2021

Kilauea – Hawaiian Islands (USA) ; HVO reported that the summit eruption at Kilauea continued during 26 October-2 November at a vent in the lower W wall of Halema`uma`u Crater. Lava entered the lake through a breach in the E part of the W wall cone, feeding the lake which had risen 52 m since 29 September. The lava lake was not level; the W end was 8 m higher than the stagnant E part on 27 October. The sulfur dioxide emission rate was high at 3,600 tonnes per day on 28 October. Lava fountains rose less than 10 m from the W vent, though by 29 October low roiling and spatter bursts were also observed.

Ulawun – New Britain (Papua New Guinea) : RVO reported increased unrest at Ulawun. Very small discrete seismic events had been recorded for the past several months by the seismometer located on the SW flank, 5 km from the summit. A small thermal anomaly was identified in satellite images at around 0500 on 3 November. At approximately 0800 RSAM values increased to 100, and by 1115, had risen to 1,400. The values fluctuated between 100 and 1,000 units at least through 1300 when the data was summarized. Tremor was detected on a seismometer at Ulamona, 11-12 km NW from the summit, during periods with higher RSAM values. Steam emissions rose from the crater.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 20 October – 26 October 2021

Aira – Kyushu (Japan) : JMA reported that incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible at night during 18-25 October. The sulfur dioxide emission rate was 1,000 tons per day on 22 October.

Cleveland – Chuginadak Island (USA) : On 20 October AVO lowered both the Aviation Color Code and the Volcano Alert Level for Cleveland to Unassigned, noting a steady decline in volcanic unrest over the previous few months. Elevated surface temperatures were still identified in satellite images, though at a reduced frequency and strength. A short-lived explosion on 1 June 2020 was the last time eruptive activity was recorded.

Dukono – Halmahera (Indonesia) : PVMBG reported that during 19 and 22-26 October white-and-gray ash plumes from Dukono rose as high as 300 m above the summit and drifted E and W.

Ebeko – Paramushir Island (Russia) : On 22 September KVERT lowered the Aviation Color Code for Ebeko to Yellow (the second lowest level on a four-color scale), noting that a thermal anomaly over the volcano was last visible on 25 August and eruptive activity had not been recorded since 22 September.

Etna – Sicily (Italy) : Strombolian activity resumed at Etna’s Southeast Crater (SEC) beginning at 0447 on 20 October. Small ash-and-gas puffs drifted SW. Activity gradually increased and by 1920 on 21 October explosions were ejecting incandescent material out of the crater. Activity intensified during the evening of 22 October, and crater incandescence was visible in between weather clouds at night during 22-23 October. Ash plumes drifted NE. Explosive Strombolian activity increased at 1000 on 23 October, producing ash plumes that then abruptly stopped at 1035. A series of strong explosions began a few minutes later, producing visible pressure waves and ash emissions. Lava fountaining began sometime before 1043 and dense ash-and-gas plumes rose several kilometers high and drifted ENE. A fracture opened on the SE side of the SEC cone and at 1048 a pyroclastic flow traveled 1.5 km SE toward the Valle del Bove. A second pyroclastic flow observed at 1100 also traveled 1.5 km SE. Several smaller pyroclastic flows were visible on the E flank of the cone. At 1158 a pyroclastic flow bifurcated and traveled a few hundred meters S and SE. Lava fountains rose as high as 800 m during the most intense period and a lava flow originating from the E side of the crater descended SE. The ash plumes rose more than 10 km (32,800 ft) a.s.l. and caused ash and lapilli to fall in many areas downwind, including Linguaglossa, Vena, Presa, Piedimonte Etneo, Taormina, and Mascali. Explosive activity began to decrease around 1200 and then ceased at 1220. Ash emissions continued to rise from the SEC and by 1932, the lava flows on the SE flank had stopped advancing.

Great Sitkin – Andreanof Islands (USA) : AVO reported that lava effusion continued at Great Sitkin during 20-26 October. Lava advanced down the S and W flanks and were 500 m long by 20 October based on satellite images. Geophysical and web camera data streams returned back online during 22-23 October; seismicity remained slightly elevated and no explosive activity was recorded in both seismic and infrasound data through 26 October. Elevated surface temperatures were visible in satellite images during 25-26 October.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that during 19-20 October explosions at Karymsky generated ash plumes that rose as high as 5 km (16,400 ft) a.s.l. and drifted 225 km E. A thermal anomaly was visible on 21 October.

Langila – New Britain (Papua New Guinea) : The Darwin VAAC reported that on 21 October ash plumes from Langila were visible in satellite images rising 1.8-4.6 km (6,000-15,000 ft) a.s.l. and drifting NW.

Lewotolok – Lembata Island (Indonesia) : PVMBG reported that the eruption at Lewotolok continued during 20-26 October. White-and-gray plumes generally rose as high as 600 m above the summit and drifted in multiple directions.

Merapi – Central Java (Indonesia) : BPPTKG reported no morphological changes to Merapi’s SW lava dome, located just below the SW rim and in the summit crater, and the summit crater dome during 15-21 October. Two pyroclastic flows traveled 2.5 km down the SW flank and as many as 60 lava avalanches traveled a maximum of 2 km SW.

Pavlof – United States : AVO reported that the eruption at Pavlof continued during 20-26 October and was focused at a vent on the upper SE flank, near the location of the 2007 vent. Seismicity remained elevated with tremor and daily small explosions during 20-24 October. Weather clouds obscured satellite and webcam images most days, but the explosions likely produced low-level ash plumes that rose no higher than 3 km (10,000 ft) a.s.l. Elevated surface temperatures were visible in satellite images during 25-26 October.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that eruptive activity at Semisopochnoi’s North Cerberus crater continued during 19-26 October. Tremor and multiple minor explosions were detected daily in seismic and infrasound data. Although weather clouds often prevented webcam and satellite views, intermittent, low-level ash emissions were visible during clear weather rising to altitudes up to 3 km (10,000 ft a.s.l.); the farthest plume drifted 250 km on 19 October. Sulfur dioxide emissions were detected during 25-26 October.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 16-17 and 20-21 October when the volcano was visible through weather clouds. A plume of resuspended ash rose as high as 4 km (13,100 ft) a.s.l. on 21 October and drifted 40 km SE.

Shishaldin – Fox Islands (USA) : AVO reported that several outages affected GPS, seismic, and infrasound stations used to monitor Shishaldin. On 20 October AVO changed both the Aviation Color Code and the Volcano Alert Level to Unassigned, reflecting the lack of this data to detect unrest. The volcano continued to be monitored with webcams, satellite data, remote infrasound, seismic, and GPS networks.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 20 October – 26 October 2021

Asosan – Kyushu (Japan) : JMA characterized the eruption at Asosan that occurred at 1143 on 20 October as medium-sized. The event ejected blocks 900 m S, produced pyroclastic flows that descended 1.3 km W, and generated an ash plume that rose 3.5 km above the crater rim. Very small eruptive events were recorded during 1244-1410. The sulfur dioxide emission rate was high at 2,500 tons per day on 21 October. White plumes rose 900 m from the crater during 21-22 October.

Karangetang – Siau Island (Indonesia) : The Darwin VAAC reported that on 25 October a pilot observed an ash plume from Karangetang rising to 3 km (10,000 ft) a.s.l. and drifting SW. Continuous ash emissions were also visible in satellite images, though emissions ceased within five hours.

Kilauea – Hawaiian Islands (USA) : HVO reported that the summit eruption at Kilauea continued during 19-26 October at a vent in the lower W wall of Halema`uma`u Crater. Lava entered the lake through a 10-m-wide breach in the E part of the W wall cone, feeding the lake which had risen 49 m since 29 September. Consistent lava fountains from the W vent rose 5-18 m with occasional bursts up to 23 m, based on field crew observations. The sulfur dioxide emission rate was high at 2,600-3,200 tonnes per day during 21-22 and 24-25 October. The lava lake was not level with the deepest parts surrounding the W vent; the W end was 8 m higher than the stagnant E part by 24 October.

Krakatau – Indonesia : PVMBG reported that at 1413 on 26 October an eruption at Anak Krakatau produced a dense gray ash plume that rose 500 m above the summit and drifted N. The eruption lasted 45 seconds based on seismic data.

La Palma – Spain : The eruption at La Palma continued during 20-26 October, characterized by Strombolian explosions, lava fountaining from multiple vents, advancing and branching lava flows, and daily ash emissions. Eruption details are based on official sources including PEVOLCA (Plan de Emergencias Volcánicas de Canarias) steering committee summaries issued daily. Seismicity remained elevated, with most earthquakes located 10-15 km deep (though some were as deep as 39 km); dozens of events were felt by local residents and some were felt across the entire island. A M 4.8 earthquake was recorded at 2248 on 19 October at a depth of 39 km, and the largest earthquake recorded since the beginning of the eruption, a M 4.9 at 38 km deep, was recorded at 1634 on 23 October; both of these events were felt across La Palma Island, as well as in some areas of Gomera and Tenerife islands. The vents in the main cone continued to effuse lava, eject tephra, and produce sometimes dense and billowing ash-and-gas plumes that rose 2.8-4 km (9,200-13,100 ft) a.s.l. Sulfur dioxide emissions fluctuated at high levels between 3,200 and 53,600 tons per day. Four vents in the main cone were active, though the activity levels varied in intensity throughout the week. A new vent opened on 19 October, in an area between the 16 October vent (located 300 m from the SE base of the main cone) and the main cone. The new vent began with explosive phreatomagmatic activity before Strombolian activity commenced. The main cone changed shape, with cycles of partial crater rim and wall collapses and growth as the eruption continued. Explosions and a lava overflow from the main cone were visible at 2000 on 22 October. A partial collapse of the NW flank of the main cone on 23 October intensified ash emissions and sent large blocks downslope; the blocks fell onto another vent, causing lava to spill out into numerous lava flows. Strong explosions were heard at 1230 and lava overflowed a vent on the flanks of the main cone at 1415. On 24 October tall lava fountains rose from at least two vents. During the afternoon, a new vent opened on the W flank and effused lava at a high rate. The vent grew taller and widened during 24-25 October. The vent located at the SE end of the fissure produced slow-moving lava flows that traveled SW. Very intense explosive activity was visible on 25 October. A small collapse of the cone was observed at 1700. At around 2100 a lava lake in the main cone increased in volume, causing a partial collapse of the upper part of the cone, and producing large, detached blocks that were carried downslope by several lava flows. Lava fountains rose about 600 m above the vent. The lava-flow field was characterized by three main areas: the initial main flow that traveled W, flowing around the S part of Montaña de Todoque, toward the sea and created a lava delta, a flow that had branched off of the main flow to the S, and the flows that traveled W along the N margins of the main flow. Lava flows sometimes overflowed their channels, forming ephemeral flows that spread laterally, descended short distances, and were also transported downslope in lava tubes. The lava flows along the northern margins (the N flow) were the most active; the flow that traveled N of Montaña Todoque had stopped, while the flow to the S of Montaña de La Laguna continued to advance and spread laterally. A lull in lava advancement during 22-23 October allowed for some homeowners to retrieve items from their residences. Lava advanced over some areas in the flow field that were previously unaffected, particularly in Alcalá, and covered an estimated 8.79 square kilometers by 26 October. The farthest end of N flows was less than 100 m from the coastline. Lava at the delta had reached 120 m water depth and rock fragments from the end of the flow were observed at depths of 360 m. The thickness of the flow at the delta was 10-30 m; lava had filled the upper and middle parts of underwater ravines and covered an area of about 0.11 square kilometers. Scientists observed an absence of marine life around the lava flows.

Manam – Papua New Guinea : According to the Darwin VAAC, ground-based observers at Manam observed on going, low-level eruptive activity on 21 October. Ash emissions rose as high as 2.4 km (8,000 ft) a.s.l. and drifted W. Within a few hours, ash had dissipated and activity was no longer visible.

Yasur – Vanuatu : The Vanuatu Meteorology and Geohazards Department (VMGD) reported that seismic activity slightly increased at Yasur beginning at 1330 on 22 October. Emissions also increased and large, dense ash-and-gas plumes were visible rising from the crater in webcam images at 1445. Increased ash emissions were confirmed during field observations later that day, prompting VMGD to expand the restricted area to a 1-km radius around the cone, defined by Danger Zone B on the hazard map. The Wellington VAAC noted that ash plumes rose as high as 1.2 km (4,000 ft) a.s.l. and drifted SE, E, and N during 22-24 October, based on webcam views and information from VMGD; emissions ceased by 1845 on 24 October.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 13 October – 19 October 2021

Aira – Kyushu (Japan) : JMA reported that incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible at night during 11-18 October. The sulfur dioxide emission rate was 800 tons per day on 11 October. A very small eruptive event was recorded on 14 October.

Bagana – Bougainville (Papua New Guinea) : The Darwin VAAC reported that on 14 October an ash plume from Bagana rose to 2.1 km (7,000 ft) a.s.l. and drifted NE based on satellite and wind model data.

Ebeko – Paramushir Island (Russia) : According to volcanologists in Severo-Kurilsk (Paramushir Island), about 7 km E of Ebeko, an explosion on 10 October produced an ash plume that rose as high as 2.5 km (8,200 ft) a.s.l. and drifted NE.

Erta Ale – Ethiopia : During 15 September-15 October satellite data showed thermal anomalies of variable intensities in Erta Ale’s S pit crater and occasional thermal anomalies at the N pit. An anomaly was detected in the N, NW, and W parts of the N pit crater on 15 October.

Great Sitkin – Andreanof Islands (USA) : AVO reported that lava effusion continued at Great Sitkin during 13-19 October. Seismicity remained elevated and was characterized by small earthquakes consistent with lava effusion, though an outage affected geophysical data streams during 16-18 October. Satellite images acquired on 11 October showed that lava filled more than half of the summit crater, flowing onto the S and W flanks, and had recently reached the N crater rim. Lava traveled 330 m down the S flank, 350 m down the W flank, descended small valleys, and in some areas, advanced over snow and ice. Blocks that had detached from the end of the W flow descended 450 m.

Karymsky – Eastern Kamchatka (Russia) : A thermal anomaly over Karymsky was identified in satellite images during 8-9 October. On 19 October KVERT lowered the Aviation Color Code to Yellow (the second lowest level on a four-color scale), noting that only gas-and-steam emissions persisted after the last ash explosions were recorded on 25 September. On 20 October explosions generated ash plumes that rose as high as 4 km (13,100 ft) a.s.l. and drifted almost 90 km ENE.

Kavachi – Solomon Islands : Satellite data showed discolored water around and to the SW of Kavachi on 12 October. Discolored water was not obviously visible in images from 2, 7, and 17 October.

Krysuvik-Trolladyngja – Iceland : Icelandic Meteorological Office (IMO) reported that during 18 September-18 October no lava effusion was detected at the Krýsuvík-Trölladyngja volcanic system. The seismic swarm that had begun on 26 September in an area SW of Keilir (about 10 km NE of the fifth vent), at the N end of the dike intrusion, had significantly decreased in mid-October. The Aviation Color Code was lowered to Yellow (the second lowest level on a four-color scale) on 18 October. IMO noted that gas emissions were ongoing, though with very low concentrations of eruptive gases. Minor thermal anomalies were detected less often; incandescence from previously emplaced lava flows was occasionally visible at night. IMO also stated that residual heat, gases, and incandescence may continue for weeks to months.

Lewotolok – Lembata Island (Indonesia) : PVMBG reported that the eruption at Lewotolok continued during 13-19 October. White, gray, and black plumes generally rose as high as 1 km above the summit and drifted in multiple directions. Rumbling and banging sounds were reported almost daily. Incandescent material was ejected most days as far as 100 m from the vent and as high as 300 m above the vent.

Merapi – Central Java (Indonesia) : BPPTKG reported minor morphological changes to Merapi’s SW lava dome, located just below the SW rim, and the dome in the summit crater during 8-14 October. The SW dome grew about 2 m taller and had an estimated volume of 1.61 million cubic meters, while the summit lava dome grew about 4 m taller had an estimated volume of 2.93 million cubic meters. As many as 41 lava avalanches traveled a maximum of 2 km SW.

Pavlof – United States : AVO reported that the eruption at Pavlof continued during 13-19 October and was focused at a vent on the upper SE flank, near the location of the 2007 vent. Seismicity remained elevated. Two small explosions were recorded in infrasound and seismic data on both 14 and 16 October. A few explosions were recorded during 17-18 October; ash deposits on the flanks were visible in satellite images. Cloudy conditions obscured satellite and webcam images most days.

Rincon de la Vieja – Costa Rica : OVSICORI-UNA reported that at 0750 on 13 October an eruption at Rincón de la Vieja produced a plume that rose 500 m above the crater rim and drifted SW. Fumarolic activity inside the crater was visible during 14-15 October.

Semeru – Eastern Java (Indonesia) : PVMBG reported that gray-and-white emissions rose 200-500 m above Semeru’s summit and drifted SW, W, and N during 12-13 and 15-16 October. Weather clouds often prevented visual observations of the summit.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that eruptive activity at Semisopochnoi’s North Cerberus crater continued during 13-19 October. Seismicity remained elevated and daily minor explosions were detected in infrasound data. Although weather clouds often prevented webcam and satellite views, intermittent, low-level ash emissions were visible rising to altitudes up to 3 km (10,000 ft a.s.l.) and drifting E on 13 October. Ash plumes rose as high as 1.5 km (5,000 ft) a.s.l. on 18 October.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 8-15 October.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that 13 explosions at Suwanosejima’s Ontake Crater produced eruption plumes that rose as high as 2.7 km above the crater rim during 11-18 October. Large volcanic bombs were ejected 500-700 m from the crater. Ashfall was reported in Toshima village (4 km SSW).

Taal – Luzon (Philippines) : PHIVOLCS reported that upwelling of hot volcanic fluids in Taal’s crater lake was visible during 13-18 October, and gas-and-steam plumes rose 1.2-3 km above the lake and drifted in multiple directions. Sulfur dioxide emissions averaged 6,393-12,611 tonnes/day, though on 15 October the emissions peaked at 23,576 tonnes/day, which was the second highest ever sulfur dioxide gas flux recorded at the volcano. Dense vog spread over the Taal Caldera region was noted on 15 October. Earthquake activity resumed on 11 October after a brief lull that first began on 27 September; 145 events characterized as mostly weak low-frequency earthquakes and volcanic tremor were recorded during 11-15 October. Volcanic tremor persisted through 18 October.

Whakaari/White Island – North Island (New Zealand) : On 18 October GeoNet reported results from a recent overflight of Whakaari/White Island. Gas measurements showed that sulfur dioxide emissions had decreased from 520 tons per day recorded at the end of September to 267 tons per day. Temperatures in the main vent area were as high as 220 degrees Celsius, similar to temperatures measure two weeks prior. Minor ash deposits from intermittent ash emissions were visible in the area close to the active vents. Seismicity was characterized by low levels of volcanic tremor and occasional low-frequency volcanic earthquakes.

EWCOLOR

A drone image captured the lava flow from Spain’s Cumbre Vieja volcano which destroyed parts of a banana plantation on La Palma and increased the size of the country as it flowed into the sea, creating new land.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 13 October – 19 October 2021

Asosan – Kyushu (Japan) : According to JMA the number of volcanic tremor signals at Asosan began on 12 October. Tremor amplitude began increasing at 1530 on 13 October, prompting JMA to raise the Alert Level to 2 (on a scale of 1-5) almost two hours later. White plumes rose 1.4 km above Nakadake Crater. An eruption was detected at 0443 on 14 October; weather clouds prevented visual confirmation of an eruption plume, though ejected incandescent material was visible in thermal camera images. During a field visit to the volcano later that day, scientists confirmed ashfall in several areas, including parts of Takamori Town (Kumamoto Prefecture), Taketa City (Oita Prefecture), and Takachiho Town (Miyazaki Prefecture). Small eruptive events occurred at 1057 and 1325 on 15 October. Volcanic tremor amplitude increased at 1400 on 18 October. During an overflight scientists observed ash deposits extending SE from Nakadake Crater. Volcanic tremor amplitude continued to fluctuate at high levels on 19 October. At 1143 on 20 October a notable eruption ejected blocks 900 m S and produced an ash plume that rose 3.5 km above the crater rim and drifted E. Pyroclastic flows descended 1.3 km W.

Kilauea – Hawaiian Islands (USA) : HVO reported that the summit eruption at Kilauea continued in Halema`uma`u Crater during 12-19 October. A 10-m-wide, horseshoe-shaped spatter rampart had formed around the W vent and was open to the E where lava was feeding the lake. For about 10 hours on 12 October a new vent N of the W vent produced 10-15-m-high lava fountains. Lava fountains from the W vent rose as high as 20 m and fed the lava lake which was 46 m deep by 18 October. The lava lake was not level with the deepest parts measured around the W vent; the W end was 4-5 m higher than the N and S parts of the lake and 12 m higher than the E end. Cooled and crusted parts of the lake’s surface overturned, or “foundered,” in all parts of the lake except the E part. The sulfur dioxide emission rate was high at 1,600-6,800 tonnes per day during 12-14 and 16-17 October.

Manam – Papua New Guinea : RVO reported that sporadic small ash emissions from Manam’s Southern Crater were observed starting at the end of September. Nighttime incandescence began on 8 October and incandescent material was occasionally ejected from the crater. The activity was characterized as moderately Strombolian with incandescent material rolling down SW Valley, visibly appearing as short lava flows. The Darwin VAAC noted that on 18 October an ash plume rose to 2.4 km (8,000 ft) a.s.l. and drifted NW. A thermal anomaly was visible in satellite images. RVO stated that at around 0800 on 20 October a large explosion at Southern Crater produced ash plumes that rose at least 1 km above the summit and drifted N and NW. According to the Darwin VAAC ash plumes rose as high as 15.2 km (50,000 ft) a.s.l. between 0840-0950, expanded radially, and then drifted E. Lower-level plumes rose 4.6-5.5 km (15,000-18,000 ft) a.s.l. and drifted NW. Later that day a collapse of newly erupted material, as well deposits from the previous few weeks, produced a debris flow that originated at the head of the valley and descended the SW Valley.

Pagan – Mariana Islands (USA) : The U.S. Geological Survey reported that ash and sulfur dioxide emissions from Pagan were last detected on 6 September. The Aviation Color Code and the Volcano Alert Level were both lowered to Unassigned on 24 September; Pagan is monitored with satellite imagery, distal geophysical data, and mariner reports and not ground-based instruments.

Rabaul – New Britain (Papua New Guinea) : On 6 October RVO raised the Alert Level for Rabaul to Stage 1 (the lowest level on a four-stage scale) due to ongoing deformation and recent increases in seismicity. During the month of September, the seismic network detected a total of 22 high-frequency volcano-tectonic earthquakes, which was more than the 12 recorded in August. The earthquakes were distributed in the Beehives, Vulcan, Greet Harbour, and Namanula areas. Deformation data from a GPS station located at the S part of Matupit Island showed a continuing trend of uplift, with 39 mm/month in August and 35-39 mm/month in September. Diffuse white fumarolic plumes rose from the crater floor and inner walls.

Vulcano – Aeolian Islands (Italy) : INGV continued to monitor elevated activity at Vulcano during 12-19 October. Scientists collected temperature, water chemistry, and gas-emissions data from four fumarolic vents located inside La Fossa Crater near the rim and from one vent near the beach. According to news articles, elevated levels of carbon dioxide impacted nearby residents in Porto Levante causing a few families to leave their homes on 13 October. Several residents had reported inexplicable illnesses and some deaths of domestic animals the previous week. On 14 October authorities restricted public access to the crater.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the Week 6 October – 12 October 2021

Aira – Kyushu (Japan) : JMA reported that incandescence from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible at night during 4-11 October. The sulfur dioxide emission rate was 400 tons per day on 5 October. An explosion at 0517 on 8 October ejected material 600-900 m away from the crater and produced an eruption plume that was obscured by weather clouds.

Kadovar – Papua New Guinea : Based on satellite and wind model data, the Darwin VAAC reported that during 8-9 October ash plumes from Kadovar rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted W and NW.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images on 7 October.

Lewotolok – Lembata Island (Indonesia) : PVMBG reported that the eruption at Lewotolok continued during 6-12 October. White-and-gray plumes generally rose as high as 800 m above the summit and drifted in multiple directions. A VONA stated that on 7 October and ash plume rose 1.9 km above the summit and drifted W. Rumbling and banging sounds were reported daily. Incandescent material was ejected daily as far as 300 m away from the vent in multiple directions, though during 5-6 October incandescent material was ejected as far as 1 km SE. BNPB noted that 25-26 eruptive events per day were sometimes recorded before activity increased in October.

Merapi – Central Java (Indonesia) : BPPTKG reported minor morphological changes to Merapi’s SW lava dome, located just below the SW rim and in the summit crater, and no changes to the summit crater dome during 1-7 October. The SW dome grew about 3 m taller had an estimated volume of 1.679 million cubic meters, and the summit lava dome had an estimated volume of 2.854 million cubic meters. As many as 76 lava avalanches traveled a maximum of 2 km SW.

Nevados de Chillan – Chile : SERNAGEOMIN reported continuing explosive and effusive activity at Nevados de Chillán’s Nicanor Crater during 16-30 September though weather conditions often prevented visual confirmation. Explosions generated plumes with low ash content that rose as high as 1.1 km above the crater rim. A new lava dome (Dome 3) in the crater was first identified on 15 September and was 27 x 40 m, elongated NW-SE, and 990 square meters in area. The dome formation was preceded by a decrease in the extrusion rates and temperatures of the L5 and L6 lava flows. By 24 September growth at Dome 3 reached 36 x 43 m and covered 2,137 square meters. Dome 4 was first visible on 29 September, adjacent to Dome 3 on the NE side, and produced a new lava flow (L7) that traveled 50 m down the flank between the L5 and L6 flows. The L5 lava flow also began to advance. On 5 October the L5 and L7 lava flows advanced and nighttime incandescence from both flows increased. Incandescence from the crater was visible in webcam images at night during 8-9 October. On 9 October a long-period earthquake was recorded at 0706 on 9 October; an associated emission rose more than 240 m above the vent and drifted NW.

Pavlof – United States : AVO reported that seismicity at Pavlof remained elevated during 6-12 October. Two explosions were recorded by infrasound network during 6-7 October. Mostly cloudy conditions obscured satellite and webcam images most days.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported a daily average of 27 explosions at Sabancaya during 4-10 October. Gas-and-ash plumes rose as high as 2 km above the summit and drifted in multiple directions. One thermal anomaly originating from the lava dome in the summit crater was identified in satellite data. Minor inflation continued to be detected near Hualca Hualca (4 km N).

Semisopochnoi – Aleutian Islands (USA) : AVO reported that eruptive activity at Semisopochnoi’s North Cerberus crater continued during 6-12 October. Seismicity remained elevated and a few explosions per day were detected in infrasound data. Although weather clouds often prevented webcam and satellite views, discontinuous, low-level ash emissions were visible rising to altitudes up to 3 km (10,000 ft a.s.l.) and drifting E during 8-9 October. Low-level ash emissions were also visible in webcam images during 9-12 October.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 1, 4, and 6-7 October. Plumes of resuspended ash drifted 200 km SE during 6-7 October.

Stromboli – Aeolian Islands (Italy) : INGV reported that during 4-10 October activity at Stromboli was characterized by ongoing explosive activity from three vents in Area N (North Crater area) and six vents in Area C-S (South-Central Crater area). Explosions from two vents in the N1 vent (Area N) ejected lapilli and bombs 80 m high, and produced minor ash emissions. Explosions at two N2 vents (Area N) averaged 3-8 events per hour and ejected material less than 80 m high. Explosions from the S1 and S2 vents in Area C-S were sporadic and occurred at a rate of 4-8 per hour; coarse material was ejected 150 m high. Gas emissions rose from the C vent. A short explosive event at the N2 vents began at 1617 on 6 October. Notably, a large explosion ejected tephra radially beyond the crater terrace as far as the upper part of the Sciara del Fuoco, and incandescent material rolled down to the coast. An ash cloud was produced, though it quickly dissipated. A small lava overflow from the vents followed but it did not travel past the upper part of the Sciara del Fuoco

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that 52 explosions at Suwanosejima’s Ontake Crater produced eruption plumes that rose as high as 2.4 km above the crater rim during 4-11 October. Large volcanic bombs were ejected as far as 1.1 km from the crater. Crater incandescence was visible nightly.