Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 14 September – 20 September 2022

Alaid – Kuril Islands (Russia) : KVERT reported that an intense thermal anomaly over Alaid identified in satellite images beginning at 1139 on 15 September (local time) likely indicated the onset of a Strombolian eruption. The Aviation Color Code was raised to Yellow (the second lowest level on a four-color scale) the next day. Satellite images acquired at 1108 on 18 September showed a gas-and-steam plume containing ash drifting ESE. Several photographs of the eruption were taken that same day.

Home Reef – Tonga Ridge : The Tonga Geological Services reported that the new island at Home Reef that emerged from the ocean on 10 September continued to grow through 20 September. The eruption continued at variable intensities, producing daily plumes of gas and steam that rose no higher than 1 km above sea level. The island was surrounded by plumes of discolored water. The island was 170 m in diameter by 16 September and had grown to 182 m N-S and 173 m E-W by 18 September. Steam plumes with some ash content rose 3 km during 19-20 September. Mariners were advised to stay 4 km away from the volcano.

Piton de la Fournaise – Reunion Island (France) : OVPF reported that a seismic crisis at Piton de la Fournaise began at 0623 on 19 September. Volcanic tremor located beneath the SSW part of the caldera began at 0748, likely signifying the arrival of magma at the surface, though weather clouds prevented visual confirmation from webcams. Pelotons de Gendarmerie de Haute Montagne (PGHM) teams that were on-site to evacuate people from inside the caldera observed lava fountains 20-30 m high rising from a fissure that had opened E of Piton Kala Pélé. The eruption was confined to the caldera. By 20 September lava fountaining had decreased and the focus of the eruption was at the lower part of the fissure. Sulfur dioxide emissions peaked at an estimated 8,000 tons per day at the beginning of the eruption and then decreased to about 2,300 tons per day during 20-21 September.

Taupo – North Island (New Zealand) : On 20 September GeoNet raised the Volcanic Alert Level for Taupo to 1 (the second lowest level on a six-level scale) reflecting “minor volcanic unrest” characterized by ongoing seismicity and inflation. Seismicity beneath Lake Taupo began increasing in May. Earthquakes occurred at a rate of about 30 per week but increased to about 40 per week in early September. A M 4.2 earthquake, the largest so far this year, was recorded on 10 September and felt by over 1,000 people. By 20 September over 700 earthquakes had been located with depths less than 30 km, though most ranged 4-13 km. The earthquake locations were in two clusters: a larger cluster beneath the central and E part of the lake, and a smaller cluster to the W centered just offshore from Karangahape. An area of deformation at Horomatangi Reef had been rising at a rate of 60 mm (plus or minus 20 mm) per year since May. The area of uplift corresponded to the main seismic swarm. The data suggested that the seismicity and deformation was caused by the movement of magma and hydrothermal fluids. GeoNet noted that unrest at calderas was common and may continue for months or years without resulting in an eruption; more significant unrest would be indicated by additional indicators of activity and substantial impacts on the local area. There have been 17 previous episodes of unrest at Taupo over the previous 150 years, some more notable than the current episode, and many others before written records. None resulted in an eruption, with the last eruption occurring around 232 CE.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 7 September – 13 September 2022

Aira – Kyushu (Japan) : JMA reported that nighttime incandescence at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible during 5-12 September. The seismic network recorded four eruptive events and seven explosions. Volcanic plumes rose as high as 2.3 km above the crater rim and ballistics were ejected as far as 1.3 km from the vent.

Ambae – Vanuatu : On 31 August the Vanuatu Meteorology and Geo-Hazards Department (VMGD) reported that the cone in Ambae’s Lake Voui continued to produce emissions consisting of steam, volcanic gases, and possibly occasional ash.

Ebeko – Paramushir Island (Russia) : KVERT reported that moderate activity at Ebeko was ongoing. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) daily explosions generated ash plumes that rose up to 4 km (13,100 ft) a.s.l. and drifted in multiple directions. A thermal anomaly over the volcano was identified in satellite images during 3 and 5-8 September.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin likely continued during 6-13 September, though weather cloud cover prevented visual confirmation with webcam and satellite images. Seismicity was very low. Weakly-elevated surface temperatures consistent with lava effusion in the summit crater were identified overnight during 12-13 September.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Karymsky was identified in satellite images during 1, 3-4, and 7-8 September.

Kilauea – Hawaiian Islands (USA): HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 6-13 September, entering the lava lake and flowing onto the crater floor. Part of the lake’s surface was continuously active. By 12 September about 111 million cubic meters of lava had been erupted from the vent since the current eruption began on 29 September 2021, raising the crater floor by 143 m.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 6-13 September. Daily white emissions rose as high as 500 m above the summit and drifted in multiple directions. During 7-8 and 10-11 September white-and-gray plumes rose as high as 700 m and 400 m above the summit, respectively, and drifted W and NW. Incandescence above the crater rim was visible in a webcam photograph captured on 13 September.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 2-8 September and seismicity remained at elevated levels. As many as 20 lava avalanches from the SW lava dome traveled down the Bebeng drainage on the SW flank, reaching a maximum distance of 1.7 km. No morphological changes to the SW and central lava domes were evident in photographs.

Pavlof – Alaska Peninsula, Alaska : AVO reported that a minor eruption at a vent on Pavlof’s upper E flank was ongoing during 6-13 September. Seismic tremor persisted. Weather clouds often prevented views of the volcano during the first part of the week, though one clear webcam view on 8 September showed a minor emission of ash or steam. Elevated surface temperatures were identified in satellite images during 10-12 September. A diffuse steam plume and new trace deposits of ash were visible in webcam images on 11 September.

Poas – Costa Rica : On 9 September OVSICORI-UNA reported that activity at Poás had increased since mid-August, characterized by notably increased seismicity. Seismic signals consisted of tremors with variable amplitudes and durations, prolonged harmonic tremors, and some long-period earthquakes with magnitudes greater than those recorded during 2022; there was no increase in low-frequency earthquakes. The energy of the seismicity had also dramatically increased in the previous few days. Sulfur dioxide emissions around the crater were mainly stable at 100 tons per day, though on a few occasions the concentrations were higher; about 300 tons per day was recorded during 17-18 August and higher than 500 tons per day was recorded on 2 September. The volume of water in Boca A lake had significantly increased during August 2021-September 2022, stabilizing at 1.4 million cubic meters between July and September with minor variations measured from week to week. Convection cells in the lake were more active and a new one formed in the N part of the lake (over the Boca C vent) since mid-August. OVSICORI-UNA stated that these data indicated disturbances to the shallow (less than 2 km) hydrothermal system and did not reflect an influx of magma. Fumarolic degassing and lake convection continued during 9-13 September.

Popocatepetl – Mexico : CENAPRED reported that there were 41-74 steam-and-gas emissions, sometimes containing minor amounts of ash, rising from Popocatépetl each day during 6-13 September. Explosions at 0343 and 0611 on 9 September produced ash plumes that rose as high as 2.5 km above the crater rim and drifted SE, and ejected incandescent material above the rim. Minor ashfall was reported in Atlixco, Puebla (23 km SE).

Rincon de la Vieja – Costa Rica : OVSICORI-UNA reported continuing eruptive activity at Rincón de la Vieja characterized by occasional small phreatic explosions. A small hydrothermal explosion at 1510 on 8 September produced a steam-and-gas plume that rose 500 m above the crater rim. During a clear observation period from 0500 to 0800 on 10 September scientists saw a continuous gas-and-steam plume and noted a hydrothermal explosion at 0640.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported moderate levels of activity at Sabancaya during 5-11 September with a daily average of 44 explosions. Gas-and-ash plumes rose as high as 2.9 km above the summit and drifted NE, E, and SE. As many as 10 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 : PVMBG reported that the eruption at Semeru continued during 6-13 September. Eruptive events at 0846 on 8 September, 0743 on 9 September, 0507 on 10 September, 0857 on 12 September, and 0524 on 13 September produced ash plumes that rose 300-700 m above the summit and drifted mainly W and SW. The Alert Level remained at 3 (on a scale of 1-4).

Semisopochnoi – Aleutian Islands (USA) : AVO reported ongoing low-level seismicity and occasional steam emissions at Semisopochnoi during 6-13 September. Satellite and webcam views were mostly obscured by weather clouds. Explosions were recorded during 12-13 September and ash emissions drifting 8 km SE at an altitude of 1.2 km (4,000 ft) a.s.l. were visible in satellite and webcam images.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that the ongoing eruption at Sheveluch was characterized by explosions, hot avalanches, and lava-dome extrusion during 2-8 September. A daily thermal anomaly was identified in satellite images. Dome collapses produced hot avalanches and ash plumes that drifted 130 km NE and SE during 2 and 5-7 September. Plumes of re-suspended ash drifted 210 km ESE during 4-5 September.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the eruption at Suwanosejima’s Ontake Crater continued during 5-12 September. A total of 15 explosions produced eruption plumes that rose as high as 2 km above the crater rim. Large blocks were ejected 700 m from the vent. Crater incandescence was observed nightly, and volcanic tremor was occasionally recorded.

Yasur – Vanuatu : On 31 August Vanuatu Meteorology and Geohazards Department (VMGD) reported that activity at Yasur continued at a high level of “major unrest,” as defined by the Alert Level 2 status (the middle level on a scale of 0-4). Ash-and-gas emissions and loud explosions continued to be recorded, with bombs falling in and around the crater.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 7 September – 13 September 2022

Alaid – Kuril Islands (Russia) : The Tokyo VAAC reported that on 10 September an ash plume from Alaid identified in satellite images rose to an altitude of 3 km (10,000 ft) a.s.l. and drifted SE.

Chikurachki – Paramushir Island (Russia) : KVERT lowered the Aviation Color Code for Chikurachki to Yellow (the second lowest level on a four-color scale) on 8 September, noting that ash plumes were last observed on 2 September and a thermal anomaly over the crater was last visible on 4 September. Gas-and-steam emissions continued to rise form the summit.

Gamalama – Halmahera : PVMBG reported that the number of deep volcanic earthquakes at Gamalama increased during the morning of 14 September and nine volcanic earthquakes were recorded. A white-and-brown plume of variable density rose as much as 250 m above the summit.

Home Reef – Tonga Ridge : The Tonga Geological Services reported that a new submarine eruption at Home Reef began at 0139 on 10 September based on a volcanic gas plume detected in satellite images. By 1259 material had formed a new small island, about 70 m in diameter and an estimated 10 m above the ocean surface. Gas emissions rose less than 1 km above the sea. Submarine activity was detected during 12-13 September, and a thermal anomaly was identified in a satellite image acquired at 1400 on 13 September.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 31 August – 6 September 2022

Aira – Kyushu (Japan) : JMA reported low but continuing activity from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) during 29 August-5 September. Small eruptive events were recorded throughout the week, and crater incandescence was visible nightly. Sulfur dioxide emissions were 2,500 tons per day on 30 August, the same rate as the last measurement on 16 August.

Dukono – Halmahera : VMBG reported that daily ash plumes from Dukono rose as high as 800 m above the summit and drifted SW, W, and NW. The plume colors were various shades white, gray, and black and had variable densities from diffuse to dense.

Ebeko – Paramushir Island (Russia) : KVERT reported that moderate activity at Ebeko was ongoing. A thermal anomaly over the volcano was identified in satellite images on 25 and 31 August. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions generated ash plumes during 25-26, 28, and 30-31 August, and 1 September, that rose up to 3.5 km (11,500 ft) a.s.l. and drifted N and E. Ashfall was reported in Severo-Kurilsk on 30 August.

Fuego – South-Central Guatemala : INSIVUMEH reported that 4-13 explosions per hour were recorded at Fuego during 30 August-6 September, generating ash plumes that rose as high as 1.1 km above the crater rim. The ash plumes drifted as far as 30 km N, NW, W, and SW, causing daily ashfall in areas downwind including Morelia (9 km SW), Panimaché I and II (8 km SW), Santa Sofía (12 km SW), El Porvenir (8 km ENE), Los Yucales (12 km SW), Sangre de Cristo (8 km WSW), El Porvenir (8 km ENE), San Pedro Yepocapa (8 km NW), and Finca Palo Verde. Daily shock waves rattled structures in communities within about 10 km around the volcano. Daily block avalanches descended the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), Honda, and Las Lajas (SE) drainages, often reaching vegetated areas. Explosions ejected incandescent material 100-300 m above the summit each day. Lahars resulting from substantial rainfall descended the Las Lajas and El Jute drainages on the ESE flank and the Ceniza drainage on the SSW flank during 29-30 August and on 2 September, carrying tree branches, trunks, and blocks as large as 2 m in diameter.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin likely continued during 30 August-6 September with lava thickening over the vent and expanding outward; the lava flows did not advance. Minor steaming from the summit was observed during 30-31 August, and elevated surface temperatures were identified in satellite images during 2-5 September. Seismicity was very low. Weather clouds sometimes prevented satellite and webcam views.

Kadovar – Northeast of New Guinea : Based on satellite and wind model data, the Darwin VAAC reported that on 31 August an ash plume from Kadovar rose to an altitude of 1.2 km (4,000 ft) a.s.l. and drifted NW.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Karymsky was identified in satellite images during 25 August-1 September.

Kilauea – Hawaiian Islands (USA) : HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 30 August-6 September, entering the lava lake and flowing onto the crater floor. Part of the lake’s surface was continuously active. The lake level mostly remained within the bounding levees, though breakouts were visible along the W and NW margins.

Klyuchevskoy – Central Kamchatka (Russia) : Strong winds re-suspended ash from the E flank of Klyuchevskoy and created plumes that were visible in satellite and webcam images drifting 180 km E on 5 September, local time. The plumes rose to altitudes of 3-4 km (9,800-13,100 ft) a.s.l.

Kuchinoerabujima – Ryukyu Islands (Japan) : The number of volcanic earthquakes with hypocenters near Kuchinoerabujima’s crater increased during 30-31 July. The number of earthquakes then decreased to low levels by 1 August and remained low. Sulfur dioxide emissions were also at low levels and on some days were below the detection limit.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 30 August-6 September. Daily white emissions rose as high as 500 m above the summit and drifted NW, W, and SW. During 1-2 September white, gray, and black plumes rose as high as 1.5 km above the summit.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 26 August-1 September and seismicity remained at elevated levels. As many as 13 lava avalanches from the SW lava dome traveled down the Bebeng drainage on the SW flank, reaching a maximum distance of 2 km. The SW lava dome had continued to grow, and had an estimated volume of 1.62 million cubic meters based on 29 August aerial photographs.

Pavlof – Alaska Peninsula, Alaska : AVO reported that a minor eruption at a vent on Pavlof’s upper E flank was ongoing during 30 August-6 September. A small vent re-opened ESE of the main vent. Seismic tremor persisted. Weather clouds mostly prevented views of the volcano during the first part of the week, though incandescence from the vent was visible in webcam images at night on 1 September; elevated surface temperatures were identified in satellite images during 2-6 September. A diffuse gas plume visible in webcam images on 4 September possibly contained trace amounts of ash. Gas plumes visible the next day contained minor amounts of ash.

Santa Maria – Southwestern Guatemala : INSIVUMEH reported that the eruption at Santa María’s Santiaguito lava-dome complex continued during 30 August-6 September. Lava-dome effusion at Caliente cone fed lava flows that descended the San Isidro and El Tambor drainages on the W and SW flanks; the flows were as long as 4.2 km by 30 August. Block avalanches from the dome, and from both the ends and sides of the flows, descended the SW and W flanks. The avalanches sometimes generated ash plumes that rose as high as 500 m above the complex. Incandescence from the dome and the lava flows was sometimes visible at night or during early mornings. Explosions during 31 August-1 September occasionally ejected incandescent material onto the flanks in all directions.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 30 August-6 September. Eruptive events at 0756 on 2 September, 0518 and 0956 on 5 September, and 0521 on 6 September produced ash plumes that rose 500-700 m above the summit and drifted mainly N and SW.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that the ongoing eruption at Sheveluch was characterized by explosions, hot avalanches, and lava-dome extrusion during 25 August-1 September. A daily thermal anomaly was identified in satellite images. Plumes of re-suspended ash drifted 150 km E on 25 August. Hot avalanches generated an ash plume on 1 September that drifted 70 km E.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the eruption at Suwanosejima’s Ontake Crater continued during 31 August-5 September. There were four explosions that likely produced eruption plumes, though weather clouds prevented visual confirmation. Large blocks were ejected 700 m from the vent. Crater incandescence was observed nightly, and volcanic tremor was occasionally recorded.

Whakaari/White Island – North Island (New Zealand) : On 7 September GeoNet reported that access to continuous data streams from the last operating earthquake and pressure sensor on Whakaari/White Island had recently been lost, hindering scientists’ ability to distinguish between various levels of unrest. Observations and gas-monitoring flights will be conducted more frequently until the island can visited to service the equipment and power supplies. Images from island webcams continued to be intermittently available. The report noted that low levels of activity on the island were observed during the last overflight on 31 August. Tall steam-and-gas plumes are sometimes observed from the mainland coast.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 31 August – 6 September 2022

Chikurachki – Paramushir Island (Russia) : KVERT reported that an ash plume from Chikurachki was identified in satellite images drifting 94 km ESE on 26 August. According to the Tokyo VAAC an ash plume was identified in satellite images at 1730 on 2 September, local time, drifting NE at an altitude of 3.7 m (12,000 ft).

Karthala – Grand Comore Island : A significant increase in the number of small earthquakes beneath Karthala’s W flank began to be detected on 15 July. The abnormal activity persisted.

Marapi – Central Sumatra : In a special notice posted on 2 September PVMBG reported that tiltmeter deformation data for Marapi showed a trend of inflation at the summit and deflation along the flanks. Seismicity continued to fluctuate with the dominating signal indicating hydrothermal activity. A phreatic eruption was the most likely kind of volcanic activity that could occur at the volcano, based on the recent data, and it could occur without warning.

Semisopochnoi – Aleutian Islands (USA) : AVO reported ongoing low-level seismicity and steam emissions at Semisopochnoi during 30 August-6 September. Weakly elevated surface temperatures were identified in satellite images during 1-2 September. Several small ash eruptions from the N crater of Mount Cerberus were visible in webcam images during 2-3 September and detected in seismic and infrasound data. Satellite and webcam views were cloudy during 4-5 September.

Ta’u – American Samoa (SW Pacific) : HVO reported that an earthquake swarm around Ta’u, in the Manu’a Islands of American Samoa, continued during 30 August-6 September. Less than 30 earthquakes per day were large enough to be felt by residents and many more earthquakes undetectable by humans were also recorded; no earthquakes were reportedly felt during 5-6 September. The data suggested that the earthquakes were consistently occurring in an area about 5-15 km off the N shore of the island, at depths of 10-15 km below the surface. There was no change in the frequency or size of earthquakes and the position of the swarm remained unchanged. USGS staff installed GPS equipment during 4-6 September.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 24 August – 30 August 2022

Aira – Kyushu (Japan) : JMA reported low but continuing activity from Minamidake Crater (at Aira Caldera’s Sakurajima volcano) during 22-29 August. Small eruptive events were recorded throughout the week, and nighttime incandescence was visible from the crater was visible during 26-29 August.

Dukono – Halmahera : PVMBG reported that almost daily white plumes from Dukono rose as high as 200 m above the summit and drifted SW, W, and NW. During 27-18 August dense white, gray, and brown ash plumes rose as high as 1 km above the summit and drifted SW and W.

Ebeko – Paramushir Island (Russia) : KVERT reported that moderate activity at Ebeko was ongoing. A thermal anomaly over the volcano was identified in satellite images during 18-19, 22, and 25 August. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions generated ash plumes that rose up to 3 km (10,000 ft) a.s.l. during 19 and 22-25 August and drifted N and E.

Erta Ale – Ethiopia : Thermal anomalies of variable intensities at Erta Ale’s N and S pit craters were periodically identified in satellite images during August. On 1 August there were two anomalies in the S pit crater and none in the N pit crater. Images were cloudy on 6 and 11 August. On 16 August two anomalies were again visible in the S pit crater while one large anomaly occupied the N crater. Translucent weather clouds obscured views on 21 August, though two anomalies were visible in the S pit crater. Dense weather clouds covered the N pit crater on 26 August and obscured the S pit crater, though one anomaly was visible.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin probably continued during 24-30 August with lava around the vent likely thickening. Weather clouds often obscured satellite and webcam views during most of the week; elevated surface temperatures were occasionally visible. Seismicity was very low.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that the eruption at Karymsky continued during 18-25 August. A thermal anomaly over the volcano was identified in satellite images during 18-19, 22, and 24-25 August.

Kilauea – Hawaiian Islands (USA) : HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 24-30 August, entering the lava lake and flowing onto the crater floor. Part of the lake was continuously active. The lake level mostly remained within the bounding levees, though daily breakouts were visible along the margins.

Klyuchevskoy – Central Kamchatka (Russia) : Strong winds re-suspended ash from the E flank of Klyuchevskoy and created plumes that were visible in satellite images drifting more than 205 km E during 25-26 August.

Lewotolok – Lembata Island : PVMBG reported that the Strombolian eruption at Lewotolok continued during 23-30 August. Daily white emissions rose as high as 700 m above the summit and drifted in multiple directions. Photos posted with daily reports showed crater incandescence and occasional Strombolian activity.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 19-25 August. Seismicity intensified compared to the previous week; in particular the number of deep volcanic earthquakes increased and indicated magmatic activity at depths less than 1.5 km. As many as 19 lava avalanches traveled down the Bebeng drainage on the SW flank, reaching a maximum distance of 1.8 km. Photo analyses showed no height changes at the SW and central lava domes, though some changes at the SW dome were observed due to avalanche activity.

Pavlof – Alaska Peninsula, Alaska : AVO reported that a minor eruption at a vent on Pavlof’s upper E flank was ongoing during 23-30 August, though there was no evidence of lava effusion. Seismic tremor persisted. A small ash emission rose to about 4 km (12,000 ft) a.s.l. on 24 August and was seen by passing aircraft. Sulfur dioxide emissions were also detected that same day.

Popocatepetl – Mexico : CENAPRED reported that there were 15-75 steam-and-gas emissions, sometimes containing minor amounts of ash, rising from Popocatépetl each day during 23-30 August. A moderate explosion was detected at 0117 on 30 August. .

Reventador – Ecuador : IG characterized the ongoing eruption at Reventador as moderate during 23-30 August. Gas-and-ash plumes, observed with webcams or reported by the Washington VAAC, rose as high as 1.6 km above the summit and drifted in multiple directions. Crater incandescence was visible on most nights and often during early morning hours. Incandescent blocks were visible rolling 500 m down the NE flank during 24-25 August and 600 m down all flanks during 28-29 August.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 23-30 August. Eruptive events at 0735 on 26 August, 0606 and 0628 on 27 August, 0623 on 28 August, and 0618 on 29 August produced ash plumes that rose 500-600 m above the summit and drifted N, W, and SW.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that the ongoing eruption at Sheveluch was characterized by explosions, hot avalanches, and lava-dome extrusion during 18-25 August. A daily thermal anomaly was identified in satellite images during 18-19, 21, and 23-25 August. Ash plumes drifted 190 km SE and 150 km E on 19 and 25 August, respectively.

Suwanosejima – Ryukyu Islands (Japan) : At 2151 on 28 August a large eruptive event at Suwanosejima’s Ontake Crater ejected large bombs 800 m above the vent and produced an eruption plume that rose into overhead weather clouds. Crater incandescence was visible in webcam images overnight. By 0900 on 29 August three more explosions were recorded and produced ash plumes that rose as high as 1.3 km above the vent.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 24 August – 30 August 2022

Chikurachki – Paramushir Island (Russia) : KVERT reported that during 23-25 August occasional ash plumes from Chikurachki rose as high as 2 km (6,600 ft) a.s.l. and drifted about 20 km E. A thermal anomaly was identified in satellite images on 25 August.

Volcano index photoNevados de Chillan – Central Chile : SERNAGEOMIN reported that on 29 August an explosion at Dome 4 in Nevados de Chillán’s Nicanor Crater produced a plume with a high tephra content that rose 2 km above the crater rim and drifted S. The explosion also generated a pyroclastic flow that descended less than 500 m on the E and SE flanks.

Ofu-Olosega – American Samoa (SW Pacific) : Data from seismometers recently installed on Tutuila, Ta’u, and Ofu-Olosega islands of American Samoa to monitor an ongoing seismic swarm indicated that the events were related to Ta’u Island and not Ofu-Olosega.

Semisopochnoi – Aleutian Islands (USA) : AVO reported ongoing low-level seismicity and steam emissions at Semisopochnoi during 23-30 August. Satellite images were mostly cloudy; steam emissions were seen almost daily in webcam images.

 

Ta’u – American Samoa (SW Pacific) : HVO reported that an earthquake swarm in the Manu’a Islands of American Samoa continued to be felt by residents of Ta’u Island and Ofu-Olosega islands during 24-30 August. Three advanced seismometers were installed beginning the second week of August, one on Ofu Island and two on Ta’u, and by 26 August the data indicated that the source of the activity was related to Ta’u Island. Around 30 earthquakes per hour were recorded each day. At 2033 on 23 August an earthquake widely felt by residents of the Manu’a islands and Tutuila Island was characterized as producing light-to-moderate shaking (a maximum Intensity of V on the Modified Mercalli Intensity Scale); the estimated M 3-3.5 event was the largest recorded since the new instruments were installed. The largest earthquakes recorded during 25-26 August had estimated magnitudes between 3 and 4 and were felt by residents of Manu’a. An estimated M 2.8 event was strongly felt at 0932 on 27 August. Numerous events were felt during 27-28 August, but none were reported during 28-30 August. Booming noises had been reported and investigated for weeks; scientists confirmed that they were related to the earthquakes, noting that the sound waves generated by some earthquakes could produce sounds audible to humans. No signs of ground cracking, landslides, rockfalls, or other activity that could have caused the sounds were seen.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 17 August – 23 August 2022

Aira – Kyushu (Japan) : JMA reported that 0009 on 15 August an explosion at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) generated an ash plume that rose 2 km above the crater rim. Sulfur dioxide emissions were slightly high at 1,500 tons per day, measured during a field visit on 16 August. Two eruptive events were recorded during 19-22 August.

Bezymianny – Central Kamchatka (Russia) : The Tokyo VAAC reported that on 22 August an ash plume from Bezymianny was identified in a satellite image rising to 3.7 km (12,000 ft) a.s.l. and drifting NE.

Bulusan – Luzon (Philippines) : PHIVOLCS lowered the Alert Level for Bulusan to 0 (on a scale of 0-5) on 21 August, noting that unrest had further declined to background levels. The frequency of volcanic earthquakes declined to baseline levels during the third week of July. Deformation data showed short-term inflation at the SE flank, though long-term data showed no deformation associated with the volcano. Sulfur dioxide emissions averaged 1,900 tonnes/day during 5-12 June and declined to about 230 tonnes/day during 25 July-6 August. Steam-laden emissions from the active vents declined to low-to-moderate levels.

Ebeko – Paramushir Island (Russia) : KVERT reported that moderate activity at Ebeko was ongoing. A thermal anomaly over the volcano was identified in satellite images on 13 and 18 August. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions generated ash plumes that rose up to 3.5 km (11,500 ft) a.s.l. during 15-18 August; ash plumes drifted more than 65 km SE during 17-18 August.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin continued during 16-23 August; no changes to the flow margins were visible but the lava had deepened around the vent. Weather clouds often obscured satellite and webcam views during most of the week. Seismicity was low and occasional local earthquakes were recorded.

Kaitoku Seamount – Volcano Islands (Japan) : JMA reported that discolored water around the Kaitoku Seamount was visible during 18-19 August.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that the eruption at Karymsky continued during 11-18 August. A thermal anomaly over the volcano was identified in satellite images during 12-13, 16, and 18 August.

Kilauea – Hawaiian Islands (USA) : HVO stated that by 16 August about 104 million cubic meters of lava had been erupted from a vent in the lower W wall of at Kilauea’s Halema`uma`u Crater since the current eruption began on 29 September 2021, raising the crater floor by 137 m. Lava continued to effuse from the vent during 17-22 August, entering the lava lake and flowing onto the crater floor. Part of the lake was continuously active. The lake level mostly remained within the bounding levees, though daily breakouts were visible along the margins.

Lewotolok – Lembata Island : PVMBG reported that the Strombolian eruption at Lewotolok continued during 17-23 August. Daily white emissions rose as high as 500 m above the summit and drifted in multiple directions. White-and-gray plumes rose as high as 300 m on 19 August. Photos in some daily reports showed Strombolian activity.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 12-18 August and seismicity remained at high levels. As many as 23 lava avalanches traveled down the Bebeng drainage on the SW flank, reaching a maximum distance of 1.8 km. Photo analyses showed no changes at the SW and central lava domes.

Nevado del Ruiz – Colombia : Servicio Geológico Colombiano’s (SGC) reported that at 1751 on 18 August an ash emission at Nevado del Ruiz rose 3.2 km and drifted WNW and was associated with a seismic signal indicating fluid movement. The plume was visible on webcams and from Manizales.

Pavlof – Alaska Peninsula, Alaska : AVO reported that a minor eruption at a vent on Pavlof’s upper E flank was ongoing during 16-23 August. There was no evidence of lava effusion, but seismic tremor persisted and multiple small explosions were detected on most days in local seismic, regional seismic, and infrasound data. During 17-18 August explosions produced minor ash emissions that rose to 3 km (10,000 ft) a.s.l. and dissipated quickly, as reported by pilots and seen in webcam images. Daily elevated surface temperatures were identified in satellite images reflecting a hot vent.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 16-23 August. Eruptive events recorded at 0544 and 0718 on 22 August produced ash plumes that rose 500 and 300 m above the summit and drifted SW and W, respectively. The Alert Level remained at 3 (on a scale of 1-4). The public was warned to stay at least 5 km away from the summit, and 500 m from Kobokan drainages within 17 km of the summit, along with other drainages originating on Semeru, including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that the ongoing eruption at Sheveluch was characterized by explosions, hot avalanches, and lava-dome extrusion during 11-18 August. A daily thermal anomaly was identified in satellite images.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the eruption at Suwanosejima’s Ontake Crater continued during 15-22 August. There were six explosions, producing eruption plumes that rose as high as 900 m above the crater rim and ejecting large blocks 600 m from the vent. Crater incandescence was observed nightly, and volcanic tremor was occasionally recorded.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 17 August – 23 August 2022

Bagana – Bougainville (Papua New Guinea) : The Darwin VAAC reported that on 22 August an ash plume from Bagana rose to 3 km (10,000 ft) a.s.l. and drifted SW based on satellite and wind model data.

Chikurachki – Paramushir Island (Russia) : Observers reported that on 22 August an ash emission from Chikurachki rose to 2 km (6,600 ft) a.s.l. and drifted E.

Krysuvik-Trolladyngja – Reykjanes Peninsula : The Institute of Earth Sciences reported that lava effusion at the fissure eruption in the Krýsuvík-Trölladyngja volcanic system continued during 16-19 August. Lava erupted mainly from a central cone, containing a lava pond, and flowed SE. Measurements taken during an overflight on 16 August indicated that the flow rate had decreased to 2 cubic meters per second. An estimated 12 million cubic meters of lava had erupted. The lava near the vent was 20-40 m thick, but flows were 5-15 m thick in the Meradalir valley, outside the crater area. Seismic tremor began to decrease on 19 August. Incandescence from the northern vent and from the lava flows was reflected by the gas plume that rose from the crater, but through the night of 20-21 August incandescence from the flow diminished. Incandescence from the vent was visible until about 0400 on 21 August. Beginning at around 0500 several explosions ejected spatter from the vent over a period of about 15 minutes. Just before 0600 a dense, bluish-gray plume rose from the crater, and simultaneously seismic tremor signals stopped.

Mayon – Luzon (Philippines) : On 21 August PHIVOLCS raised the Alert Level for Mayon to 1 (on a 0-5 scale) noting changes at the summit lava dome that was emplaced in 2018. Changes in morphology of the dome and minor extrusion estimated at about 40,000 cubic meters was detected during 6 June-20 August based on daily visual and camera monitoring data. Minor inflation, particularly on the NW and SE flanks, had been recorded since April. Sulfur dioxide emissions averaged 688 tonnes/day on 12 August, near baseline levels. Seismic activity was at baseline levels for most of 2022, though short-lived spikes in the number of low-frequency volcanic earthquakes were recorded on 26 May and 20 June. Based on the data PHIVOLCS stated that the dome growth was likely the result of gas pressurization at shallow depths.

Nevados de Chillan – Central Chile : On 11 August SERNAGEOMIN reported that the lava dome on the floor of Nevados de Chillán’s Nicanor Crater had grown taller in the previous few days based on webcam views. The portion of the dome that was visible with the webcam was reddish and rocky. The report noted that an increase in sulfur dioxide emissions and more intense explosions had been detected since 18 July. Similarly, an increase in the intensity and occurrence of thermal anomalies in the crater had been noted since 18 July, though anomalies had further intensified during the recent period of dome extrusion. An explosion at 1041 on 10 August was followed by the most intense thermal anomaly recorded during the last month.

Ofu-Olosega and Ta’u – American Samoa (SW Pacific) : HVO reported that an earthquake swarm in the Manu’a Islands of American Samoa continued to be recorded and felt by residents of Ta’u Island and Ofu-Olosega. About 20 earthquakes per hour were recorded by four microseismometers distributed on Tutuila, Ta’u, and Ofu-Olosega Islands. The largest events were estimated to be between magnitudes 2 and 3; most events are too small to be felt. Analysis of the seismic data indicated that the earthquakes were occurring beneath or around the Manu’a Islands, likely closer to Ta’u rather than Ofu-Olosega, though the exact locations, depths, and magnitudes were unknown. The number, size, and frequency of earthquakes recorded by instruments and being felt by people and on both islands indicated that seismicity was above background levels. Earthquakes continued to be recorded at around the same rate during 20-22 August. Two additional seismometers were installed on Ta’u during 22-23 August.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that at 1347 on 21 August a short-lived explosion at Semisopochnoi’s North Cerberus cone produced an ash emission that was visible in webcam images. The ash emission was not visible in satellite images due to weather clouds, indicating that they did not rise above 6 km (20,000 ft) a.s.l. This was the first explosion detected since 12 June.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 10 August – 16 August 2022

Aira – Kyushu (Japan) : JMA reported that nighttime incandescence at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible during 8-15 August. The seismic network recorded 33 eruptive events and 12 explosions. Volcanic plumes rose as high as 2.5 km above the crater rim and material was ejected large ballistics as high as 1.7 km above the summit.

Ebeko – Paramushir Island (Russia) : KVERT reported that moderate activity at Ebeko was ongoing. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions generated ash plumes that rose up to 3.5 km (11,500 ft) a.s.l. and drifted in multiple directions during 4-5 and 7-8 August. A thermal anomaly over the volcano was identified in satellite images during those same days.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin continued during 9-16 August; no changes to the flow margins were visible but the lava had deepened around the vent. Weather clouds often obscured satellite and webcam views during most of the week. Seismicity was low and occasional local earthquakes were recorded. Elevated surface temperatures were identified in satellite images on most days.

Ibu – Halmahera : PVMBG reported that the eruption at Ibu continued during 9-16 August. Gray-and-white ash plumes of variable densities generally rose as high as 1.5 km above the summit and drifted in multiple directions.

Kadovar – Northeast of New Guinea : Based on satellite and wind model data, the Darwin VAAC reported that on 14 August an ash plume from Kadovar rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted NW.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that the eruption at Karymsky continued during 4-11 August. A daily thermal anomaly over the volcano was identified in satellite images. Explosions during 5-9 August produced ash plumes that rose as high as 5 km (16,400 ft) a.s.l. and drifted 550 km in multiple directions.

Kilauea – Hawaiian Islands (USA) : HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 9-16 August, entering the lava lake and flowing onto the crater floor. Part of the lake was continuously active. The lake level mostly remained within the bounding levees, though daily breakouts were visible along the margins.

Krakatau – Sunda Strait : PVMBG reported that cloudy weather often prevented visual confirmation of the ongoing eruption at Anak Krakatau during 9-16 August. Incandescence at or near the vent was seen in nighttime photos on most days.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 5-11 August and seismicity remained at high levels. As many as 43 lava avalanches traveled down the Bebeng drainage on the SW flank, reaching a maximum distance of 1.5 km.

Pavlof – Alaska Peninsula, Alaska : AVO reported that a minor eruption at a vent on Pavlof’s upper E flank was ongoing during 9-16 August, though cloud cover often prevented visual confirmation. Seismic tremor persisted and multiple small daily explosions were detected in local and regional seismic and infrasound data. The explosions may have produced minor ash emissions that rose no higher than 3 km (10,000 ft) a.s.l. and dissipated quickly, though on a few of the clear views none were seen. Elevated surface temperatures were identified in satellite images on most of the days.

Popocatepetl – Mexico : CENAPRED reported that there were 19-204 steam-and-gas emissions, sometimes containing minor amounts of ash, rising from Popocatépetl each day during 9-16 August. A minor explosion was recorded at 0839 on 10 August and a moderate explosion was detected at 1528 on 11 August. Minor ashfall was reported in the municipality of Ecatzingo, State of Mexico. An explosion at 1952 on 13 August was followed at 2125 by minor amounts of ashfall in Tetela del Volcán.

Sangay – Ecuador : IG reported that a notable increase in seismicity at Sangay began at around 1000 on 12 August and was followed by the effusion of a lava flow that descended more than 1 km on the SE flank. Strombolian activity was visible at the summit. Ash plumes rose as high as 3.5 km above the summit and drifted 500 km W and SW, past the coastline, and caused daily ashfall in the provinces of Chimborazo and Guayas during 12-16 August.

Semeru – Eastern Java : The eruption at Semeru continued during 10-16 August. The Darwin VAAC reported that during 13-16 August ash plumes rose to altitudes of 4.3-4.6 km (14,000-15,000 ft) a.s.l. and drifted SW and W based on satellite images and wind models. The Alert Level remained at 3 (on a scale of 1-4).

Sheveluch – Central Kamchatka (Russia) : KVERT reported that the ongoing eruption at Sheveluch was characterized by explosions, hot avalanches, and lava-dome extrusion during 4-11 August. A daily thermal anomaly was identified in satellite images, and gas-and-steam plumes containing some ash were visible drifting 70 km E and SE during 8-9 August.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the number of daily explosions at Suwanosejima’s Ontake Crater began increasing on 2 August and remained elevated through 7 August; their frequency began decreasing on 8 August. About 11 explosions were recorded during 8-15 August. Eruption plumes rose as high as 2 km above the crater rim and large ballistics were ejected as far as 800 m from the crater. Incandescence from the crater was often visible at night.

Taal – Luzon (Philippines) : PHIVOLCS reported that sulfur dioxide emissions at Taal averaged 3,802-6,844 tonnes per day during 9-10 and 12-15 August; a high of 13,572 tonnes per day was recorded on 11 August causing significant vog around the caldera and a sulfur odor reported by residents of Banyaga, (Agoncillo), Poblacion 5, Boso-boso, and Gulod (Laurel), and Poblacion (Talisay). Upwelling volcanic gasses and fluids in the lake were visible, along with voluminous steam-rich plumes that rose as high as 3 km above the lake and drifted mainly NE, SE, and SW.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 10 August – 16 August 2022

Krysuvik-Trolladyngja – Reykjanes Peninsula : The fissure eruption in the Krýsuvík-Trölladyngja volcanic system that began on 3 August continued in the Meradalir valley during 10-16 August. Lava erupted mainly from a central cone and flowed ESE. According to the Institute of Earth Sciences the effusion rate had notably decreased, from an average of 11 cubic meters per second during 4-13 August to 3-4 cubic meters per second during 13-15 August. A news article stated that the effusion rate significantly decreased during 0530-0630 on 13 August based on information from IMO staff who were investigating the eruption site for new changes. The Institute of Earth Sciences estimated that 10.6 million cubic meters of lava had covered an area of 1.25 square kilometers by 15 August. Data collected during an overflight on 16 August indicated that the effusion rate had further reduced to 2 cubic meters per second during the previous day, though the uncertainty in that estimate was high. On 16 August residents reported seeing a purple-tinged sulfur dioxide gas cloud over the eruption area slowly drifting SW during sunrise.

Ta’u – American Samoa (SW Pacific)  : HVO reported that earthquakes were felt by residents of the Manu?a group of islands in American Samoa beginning on 26 July. Residents of Ofu and Olosega islands began reporting earthquakes on 10 August. Experts from HVO, Pago Pago National Weather Service Office (NWS), National Oceanic and Atmospheric Administration (NOAA) Pacific Tsunami Warning Center, NOAA-IOC (NOAA-Intergovernmental Oceanographic Commission), International Tsunami Information Center, and USGS National Earthquake Information Center have been working together to respond to the unrest. USGS scientists arrived on the islands and installed two microseismometers, one in Fiti?uta village on Ta?u island on 13 August and the other in Olosega village on 14 August. The instruments began recording about 20 earthquakes per hour. The largest earthquakes, including the felt events, were estimated to be between magnitudes 2 and 3; most of the events were too small to be felt. The exact location and depth of these earthquakes was unknown, due to limited earthquake monitoring equipment, though the data suggested that the events were beneath the Manu?a Islands, likely closer to Ta?u island rather than Ofu-Olosega, and were probably not related to the recently active Vailulu?u seamount. HVO noted that American Samoa’s volcanoes were monitored remotely by satellites and a distant seismic station in Apia, Samoa; the lack of ground-based monitoring stations does not allow for advanced warning of new activity. Both the Volcano Alert Level and Aviation Color Code were categorized as Unassigned due to the lack of a volcano-monitoring network.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 3 August – 9 August 2022

Ebeko – Paramushir Island (Russia) : KVERT reported that moderate activity at Ebeko was ongoing during 28 July-4 August. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions generated ash plumes that rose up to 4.5 km (14,800 ft) a.s.l. and drifted in multiple directions. A thermal anomaly over the volcano was identified in satellite images during 1 and 3-4 August.

Fuego – South-Central Guatemala : INSIVUMEH reported that 3-10 explosions per hour were recorded at Fuego during 2-9 August, generating ash plumes that rose as high as 1.1 km above the crater rim. The ash plumes drifted as far as 30 km W and SW, causing daily ashfall in areas downwind including Morelia (9 km SW), Panimaché I and II (8 km SW), Santa Sofía (12 km SW), El Porvenir (8 km ENE), Los Yucales (12 km SW), Sangre de Cristo (8 km WSW), El Porvenir (8 km ENE), San Pedro Yepocapa (8 km NW), Ojo de Agua, and Finca Palo Verde. Daily shock waves rattled structures in communities around the volcano and rumbling was occasionally heard. Daily block avalanches descended the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), Honda, and Las Lajas (SE) drainages. Explosions ejected incandescent material 100-300 m above the summit each day.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin likely continued during 2-9 August; no changes to the flow lengths were visible but the lava had deepened around the vent. Weather clouds often obscured satellite and webcam views during most of the week, though no activity was visible when views were clear. Seismicity was low and occasional local earthquakes were recorded. Elevated surface temperatures were identified in satellite images during 5-9 August.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that the eruption at Karymsky continued during 29 July-4 August. Explosions during 29-31 July, 1-2 August, and 4 August produced ash plumes that rose 4-8 km (13,100-26,200 ft) a.s.l. and drifted 230 km S, SE, and E. A thermal anomaly over the volcano was identified in satellite images during 31 July-4 August.

Kilauea – Hawaiian Islands (USA) : HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 2-9 August, entering the lava lake and flowing onto the crater floor. The lake level remained within the bounding levees. Daily minor ooze-outs were visible along the margins of the crater floor. Intense incandescence from the W vent was visible during 5-9 August.

Krakatau – Sunda Strait : PVMBG reported that the eruption at Anak Krakatau continued during 3-9 August. Several eruptive events occurred on 3 August (at 0034, 0115, and 1540), sometimes producing dense black ash plumes that rose as high as 1.5 km above the summit and drifted SW. At 0926 on 4 August a dense gray-to-black ash plume rose 1.5 km and drifted N. Incandescence at or near the vent was seen in nighttime photos on most days. Diffuse white plumes were visible rising from the volcano during 7-8 August.

Lewotolok – Lembata Island : PVMBG reported that the Strombolian eruption at Lewotolok continued during 2-9 August. Daily white or white-and-gray emissions rose as high as 400 m above the summit and drifted in multiple directions. Photos in some posted reports showed Strombolian activity.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 29 July-4 August. Seismicity remained at high levels. As many as 34 lava avalanches traveled down the Bebeng drainage on the SW flank, reaching a maximum distance of 1.8 km. The volumes of both the SW and central lava domes were unchanged based on photo analyses.

Nevado del Ruiz – Colombia : On 2 August Servicio Geológico Colombiano’s (SGC) reported that during the previous week the number and size of seismic signals indicating fluid movement had increased at Nevado del Ruiz compared to the week before, though they remained at moderate levels. Although seismic signals indicating rock fracturing increased in number, magnitudes were similar to the previous week. Several episodes of drumbeat seismicity were recorded, indicating continuing growth of the lava dome. Gas-and-steam emissions rose from the crater, reaching just over 2.4 km above the summit on 30 July. Several thermal anomalies in Arenas Crater were identified in satellite images during 0500-0600 on 4 August, and seismic signals indicating emissions were recorded during 4-5 August. Ashfall was reported in the municipalities of Santa Rosa de Cabal, Pereira, Villamaría, Manizales, and Dosquebradas. Tephra deposits were visible near the crater and in areas up to 3 km away.

Pavlof – Alaska Peninsula, Alaska : AVO reported that a minor eruption at a vent on Pavlof’s upper E flank was ongoing during 3-9 August. Seismic tremor persisted and multiple daily explosions were detected in local and regional seismic and infrasound data. The explosions likely produced minor ash emissions that rose no higher than 3 km (10,000 ft) a.s.l., though cloud cover prevented confirmation on most days. Strongly elevated surface temperatures were identified in satellite images during 7-8 August.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported moderate levels of activity at Sabancaya during 1-7 August with a daily average of 19 explosions. Gas-and-ash plumes rose as high as 2.7 km above the summit and drifted E, SE, SW, and W. As many as seven 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).

Santa Maria – Southwestern Guatemala : INSIVUMEH reported that the eruption at Santa María’s Santiaguito lava-dome complex continued during 2-9 August. Lava flows continued to advance in the San Isidro and El Tambor drainages on the W and SW flanks and were as long as 3.7 km by 5 August. Block avalanches from the W part of Caliente cone, and from both the ends and sides of the flows descended the S, SW, and W flanks. The avalanches generated ash plumes that rose about 1 km and drifted SW, S, and E, causing ashfall in areas downwind including La Florida, Monte Claro, San Marcos Palajunoj, Loma Linda, and Las Marías. Incandescence from Caliente cone and the lava-flow fronts was sometimes visible at night.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 3-9 August. Eruptive events recorded at 0810 on 3 August, 0628 on 4 August, 1245 on 5 August, and 0720 on 6 August produced ash plumes that rose 500-700 m above the summit and drifted SW and N.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that the ongoing eruption at Sheveluch was characterized by explosions, hot avalanches, and lava-dome extrusion during 29 July-4 August. A daily thermal anomaly was identified in satellite images, and ash plumes were visible drifting 24 km SW on 31 July.

Stromboli – Aeolian Islands (Italy) : INGV reported that during 1-7 August activity at Stromboli was characterized by ongoing explosions from two vents in Area N (North Crater area) and two vents in Area C-S (South-Central Crater area). Low-intensity explosions from the N1 vent (Area N) ejected mostly ash, with some course material, 80-150 m high at a rate of 2-6 explosions per hour. The N2 vent (Area N) emitted gases. No explosions occurred at the S1 and C vents in Area C-S; low-intensity explosions at two S2 vents ejected coarse material 80-150 m high at a rate of 3-4 explosions per hour.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the number of explosions at Suwanosejima’s Ontake Crater increased during 2-8 August, when around 30 were recorded; nine of those were detected on 7 August. During 7-8 August eruption plumes rose as high as 2 km above the crater rim and mingled with weather clouds. Large ballistics were ejected 600 m from the crater’s center. Incandescence from the crater was visible at night.

Taal – Luzon (Philippines) : PHIVOLCS reported increases in both sulfur dioxide emissions at Taal and activity in Main Crater Lake. Sulfur dioxide emissions averaged 1,289 tonnes per day from May to mid-June, and increased to an average of 4,952 tonnes per day during 15 July-3 August. Sulfur dioxide emissions further increased to 12,125 and 17,141 tonnes per day on 3 and 7 August, respectively, prompting PHIVOLCS to issue advisories. Vog was present over the W part of Taal Caldera during 2-3 August; dense vog in Laurel and Banyaga (Agoncillo, Batangas Province) also damaged vegetation. A sulfur odor was reported by residents of Tagaytay City and Bugaan East. Upwelling gasses and hot fluids in the lake, and voluminous steam-rich plumes rising as high as 2.8 km above the lake, were visible during 1-9 August. Recent low-frequency seismic events and tremor were characterized as above background.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 3 August – 9 August 2022

Aira – Kyushu (Japan) : JMA reported that nighttime incandescence at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) was visible during 1-8 August. The seismic network recorded 25 eruptive events and seven explosions. Volcanic plumes rose as high as 2.8 km above the crater rim and material was ejected material as high as 1.3 km above the summit.

Grimsvotn – Iceland ” The Icelandic Meteorological Office (IMO) reported that seismicity at Grímsvötn had declined to normal levels during the past few days, and no significant variations from background levels were observed in geochemical or deformation data.

Ioto – Volcano Islands : JMA reported that minor eruptive activity off the coast at Ioto (Iwo-jima) had been visible daily during 11-31 July. On 14 July pumice pieces from the eruption washed up onto the shore at Onohama and were photographed during a field survey conducted by the National Research Institute for Earth Science and Disaster Prevention. JMA scientist visited the site on 31 July and confirmed the pumice deposits on the beach. They saw eruptive activity every few minutes, and gray, tephra-laden columns of water being ejected 20-30 m above the ocean’s surface. A satellite image on 4 August showed a small rounded gray zone at the water surface and a plume of discolored water drifting NE.

Krysuvik-Trolladyngja – Reykjanes Peninsula : The fissure eruption of the Krýsuvík-Trölladyngja volcanic system that began at around 1318 on 3 August continued at least through 9 August. Numerous small lava fountains rose along the fissure, located near the border of the previous flow field N of Fagradalsfjall, and lava flows traveled downslope to the NW. Scientists from the Institute of Earth Sciences stated that the initial flow rate was 5-10 times greater than the flow rate at the start of the 2021 eruption, based on model estimates, field data, and satellite measurements. The flow rate was about 32 cubic meters per second during the initial hours of the eruption, then decreased to an average of 18 cubic meters per second from 1700 on 3 August until 1100 on 4 August, by which time about 1.6 million cubic meters of lava had covered an area of 0.14 square kilometers. The average flow thickness was around 11 m. According to a news article the length of the active fissure had decreased and the middle part of the fissure was the most active. On 5 August Icelandic Meteorological Office (IMO) reported that the number of daily earthquakes declined after the eruption began and deformation stabilized. Thousands of people were walking on the trails to view the eruption; authorities warned the public to heed inclement weather warnings, and closed access to the site during 7-9 August due to weather conditions and trail maintenance.

Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 27 July – 2 August 2022

Ebeko – Paramushir Island (Russia) : KVERT reported that moderate activity at Ebeko was ongoing during 21-28 July. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions generated ash plumes that rose up to 4 km (13,100 ft) a.s.l. and drifted in multiple directions.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin continued during 26 July-2 August. Weather clouds obscured satellite and webcam views during most of the week, though satellite radar data confirmed ongoing effusion; flows thickened but did not advance. Seismicity was low, and occasional local earthquakes were recorded. Steam emissions were visible in satellite and webcam images during 29-30 July.

Grimsvotn – Iceland : The Icelandic Meteorological Office (IMO) reported that increased seismicity, characterized by several earthquakes with magnitudes over 1, began at Grímsvötn during the afternoon of 2 August and continued through the afternoon of 3 August. The largest event was a M 3.6 detected at 1424.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a thermal anomaly over Karymsky was identified in satellite images during 21-23 and 27-28 July. Ash plumes were identified in satellite images drifting 46 km ESE on 27 July.

Kilauea – Hawaiian Islands (USA): HVO reported that lava continued to effuse from a vent in the lower W wall of Kilauea’s Halema`uma`u Crater during 26 July-2 August, entering the lava lake and flowing onto the crater floor. Minor ooze-outs along the margins of the crater floor were visible during 1-2 August. The lake level remained at the bounding levees.

Krakatau – Sunda Strait : PVMBG reported that the eruption at Anak Krakatau continued during 27 July-2 August. Several eruptive events occurred on 2 August (at 1549, 1835, 1906, 2249, and 2319) and on 3 August (at 0034, 0115, and 1540), sometimes producing black ash plumes that rose as high as 1.5 km above the summit and drifted NE and SW.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 22-28 July. Based on photo analyses, the volumes of both the SW and central lava domes had increased, with recent volume estimates of 1.67 and 2.79 million cubic meters, respectively. Seismicity remained at high levels. As many as 47 lava avalanches traveled down the Bebeng drainage on the SW flank, reaching a maximum distance of 1.8 km.

Pavlof – Alaska Peninsula, Alaska: AVO reported that a minor eruption at a vent on Pavlof’s upper E flank was ongoing during 26 July-2 August. Daily elevated surface temperatures were identified in satellite images. Seismic tremor persisted and multiple daily explosions were detected in local and regional seismic and infrasound data. The explosions likely produced minor ash emissions that rose no higher than 3 km (10,000 ft) a.s.l., though cloud cover prevented confirmation on most days. Ash emissions were visible in webcam images during 27-28 July. Sulfur dioxide gas emissions were visible on 26 July and team emissions were noted during 30-31 July.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 27 July-2 August. Eruptive events recorded at 0637 on 27 July, 0926 on 29 July, 0825 on 31 July, 0757 on 1 August, 0555 on 2 August, and 0810 on 3 August produced ash plumes that rose 500-700 m above the summit and drifted SW.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that the ongoing eruption at Sheveluch was characterized by explosions, hot avalanches, and lava-dome extrusion during 21-28 July. A daily thermal anomaly was identified in satellite images, and ash plumes were visible drifting 74 km SSW and SE on 22 and 24 July.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the eruption at Suwanosejima’s Ontake Crater continued during 25 July-2 August. One explosion produced an eruption plume that rose more than 1.8 km above the crater rim and caused ashfall in Toshima village (3.5 km SSW).

Yufu-Tsurumi – Kyushu (Japan) : JMA lowered the Alert Level for Yufu-Tsurumi to 1 (on a scale of 1-5) on 27 July, noting that seismicity had decreased after the 8 July earthquake swarm; no volcanic earthquakes were recorded on 9 July and afterwards.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 27 July – 2 August 2022

Aira – Kyushu (Japan) : JMA lowered the Alert Level for Aira Caldera’s Sakurajima volcano to 3 (on a 5-level scale) on 27 July, noting that after the larger eruption on 24 July material had not been ejected more than 2 km from the crater; residents were warned to stay 2 km away from the crater. During 25 July-1 August the seismic network recorded about 11 explosions and 19 eruptive events, producing plumes that rose as high as 2.2 km above the summit and ejected material far as 1.1 km. Crater incandescence was visible nightly. No deformation was detected.

Askja – Iceland : On 27 July IMO stated that uplift at Askja began in August 2021 and since then had totaled 35 cm, centered in the W part of Askja lake. The uplift was rapid, compared to similar volcanoes around the world, and likely caused by a magmatic intrusion at an estimated depth of 2 km. Seismicity remained low.

Ioto – Volcano Islands : Satellite images of Ioto (Iwo-jima) acquired on 15 July showed a darker area in the water along the SE coast, possibly above or near the 2001 vent, and a plume of discolored water drifting NE. Video taken on or around 25 July showed a white plume rising from the same area. Satellite images during 30-31 July showed small rounded gray zones at the water surface.

Krysuvik-Trolladyngja – Reykjanes Peninsula : Icelandic Meteorological Office (IMO) reported that an intense earthquake swarm began around noon on 30 July within the Krýsuvík-Trölladyngja volcanic system. The earthquakes were located in an area just NE of lava field in Geldingadalir, along the dike intrusion that preceded the March-September 2021 eruption. The swarm was likely caused by a magmatic intrusion at depths of 5-7 km. Earthquakes were reportedly felt in SW Iceland, in Reykjanesbær, Grindavík, the Capital region, and as far as Borgarnes. Several earthquakes were above M 3; a larger M 4 event was recorded at 1403. IMO raised the Aviation Color Code to Yellow, based on above-background seismic levels. At around 1800 the epicenters shallowed to depths of 2-5 km. By 1527 on 31 July almost 3,000 earthquakes had been detected, with four of the events larger than an M 4. A larger M 5.4 earthquake was detected at 1748. IMO reported at 1749 on 2 August that deformation models indicated magma around 1 km below the surface. The intrusion rate was close to double that recorded prior to the 2021 eruption, though by the reporting time the intrusion and seismicity rates had slowed. IMO noted that a similar pattern of events took place prior to the last eruption and stated that the likelihood of an eruption had increased. An effusive eruption began at 1315 on 3 August in Meradalir, near the border of the previous flow field N of Fagradalsfjall. Webcam video showed lava fountains rising along a 300-m-long fissure.

Kuchinoerabujima – Ryukyu Islands (Japan) : JMA reported that the number of volcanic earthquakes with hypocenters near Kuchinoerabujima’s crater began increasing around 1000 on 30 July and remained elevated. The Alert level was raised to 2 (on a scale of 1-5) on 31 July. Around 40 volcanic earthquakes were recorded by 1500 on 1 August. JMA noted that daily emissions of sulfur dioxide gas remained low, with a rate less than 50 tons per day. No deformation was detected.

Raung – Eastern Java : According to PVMBG an eruption at Raung at 1719 on 27 July produced a gray ash plume that rose 1-1.5 km above the summit and drifted W and NW. On 28 July a thermal anomaly in the crater was identified in satellite images and data from the GPS network indicated inflation, likely from an intrusion of magma. Seismicity on 29 July was dominated by continuous tremor. The Alert Level was raised to 2 (on a scale of 1-4) that same day, and the public was warned to stay 3 km away from the crater.