Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 28 September – 4 October 2022

Aira – Kyushu (Japan) : JMA reported that 11 eruptive events and five explosions at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) were recorded during 26 September-3 October. Volcanic plumes rose as high as 2.8 km above the crater rim and large blocks were ejected as far as 1.7 km from the vent. Incandescence at the crater was visible nightly.

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 to 3.5 km (11,500 ft) a.s.l. and drifted E during 22-24 and 27-28 September. On 22 and 28 September the ash plumes that drifted E and N produced ashfall in Severo-Kurilsk. A thermal anomaly over the volcano was identified in satellite images on 23 and 28 September.

Great Sitkin – Andreanof Islands (USA) : AVO reported that continuing slow lava effusion at Great Sitkin was confirmed by a 27 September satellite image and likely continued during 28 September-4 October. Elevated surface temperatures were identified during 28-29 September; weather clouds often prevented webcam and satellite views during the rest of the week. Seismicity remained at low levels.

Karthala – Grand Comore Island : According to the Direction Générale de la Sécurité Civile (DGSC) – Comores on 4 October, the Observatoire Volcanologique du Karthala (OVK) reported that activity at Karthala had significantly declined during the previous few days.

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 27 September-4 October, entering the lava lake. The active part of the lake stayed at a relatively steady level through the week, varying only slightly. Sulfur dioxide emissions were approximately 970 and 1,800 tonnes per day on 28 and 30 September, respectively.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 27 September-4 October. White emissions rose as high as 350 m above the summit and drifted E, SE, W, and NW on most days. White-and-gray plumes rose as high 500 m and drifted NW, W, and E during 29-30 September and 1-2 October.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 23-29 September and seismicity remained at high levels. As many as seven lava avalanches from the SW lava dome traveled down the Bebeng drainage on the SW flank, reaching a maximum distance of 1.8 km. No morphological changes to the central lava domes were evident in photographs, while the SW dome grew about 1 m taller.

Nevados de Chillan – Central Chile : SERNAGEOMIN reported that two long-period earthquake signals were recorded at Nevados de Chillán at 0813 on 3 October and 1630 on 4 October, and both were followed by a dense ash emission. The ash plume from the first event rose 760 m above the summit and drifted SSW, while the ash plume from the second event rose as high as 1.9 km and also drifted SSW.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported moderate levels of activity at Sabancaya during 5-11 September with a daily average of 46 explosions. Gas-and-ash plumes rose as high as 3 km above the summit and drifted NE, E, and SE. As many as nine 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 27 September-4 October. Eruptive events at 0459 and 0726 on 2 October produced ash plumes that rose 500-700 m above the summit and drifted S and SW. T

Semisopochnoi – Aleutian Islands (USA) : No ash emissions or explosive activity have been detected since 14 September. Seismicity had decreased, though remained at elevated levels. Steam emissions from the active vent in the N crater of Mount Cerberus persisted. Seismic tremor and a small explosion were detected in seismic and infrasound data during 3-4 October.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that the ongoing eruption at Sheveluch was characterized by explosions, hot avalanches, and lava-dome extrusion during 15-22 September. A daily thermal anomaly was identified in satellite images. Plumes of re-suspended ash drifted 113 km E on 23 September.

Stromboli – Aeolian Islands (Italy) : INGV reported that during 26 September-2 October activity at Stromboli was characterized by ongoing explosions from three vents in Area N (North Crater area) and at least two vents in Area C-S (South-Central Crater area). Low-intensity explosions from the N1 vent (Area N) ejected course material (bombs and lapilli) 80-150 m high at a rate of 3-5 explosions per hour. Spattering was visible at the N2 vent (Area N). Explosions from at least two vents in Area C-S, which were not visible due to the camera views, ejected ash and course material less than 150 m above the vent at a rate of 1-5 events per hour. At 1524 on 29 September an explosion at N2 generated an ash plume that rose 300 m above the summit and ejected abundant amounts of lava fragments, lapilli, and bombs along the Sciara del Fuoco. Four subsequent, low-intensity explosions ejected tephra 100 m high. Spattering activity at the vent intensified afterwards and through the next day. Beginning at 1115 on 3 October a lava flow emerged from Area N and traveled down the Sciara del Fuoco, reaching the ocean.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the eruption at Suwanosejima’s Ontake Crater continued during 30 September-3 October. A total of 38 explosions produced eruption plumes that rose as high as 1.6 km above the crater rim and occasionally ejected large bombs from the vent. Crater incandescence was visible nightly and ash sometimes fell in Toshima village (3.5 km SSW).

Taal – Luzon (Philippines) : In a special advisory, PHIVOLCS reported that sulfur dioxide emissions at Taal were as high as 10,718 tonnes per day on 29 September, creating a significant amount of vog over the caldera. Voggy conditions were reported by residents of Laurel, Agoncillo, and Santa Teresita, Batangas. The report noted that sulfur dioxide emissions had been increasing since 15 July and averaged 6,612 tonnes per day in September. In early August degassing at the volcano increased characterized by the upwelling of hot fluids in the lake and steam-rich plumes rising as high as 2.5 km above the lake’s surface.

Ta’u – American Samoa (SW Pacific) : Seismic activity has dramatically decreased and maintained low levels over the past few weeks. Analysis of data from one seismometer that had recorded earthquakes during 2005-2009 suggested that a rate of five detected earthquakes per day was characteristic of long-term background seismicity; the current earthquakes rates were at background levels.

Villarrica – Central Chile : On 3 October SERNAGEOMIN reported that recent passive emissions from Villarrica contained tephra that was deposited on the upper SW flank. Evidence suggested that there were recent fluctuations in the intensity of activity at the lava lake in the main crater.

Whakaari/White Island – North Island (New Zealand) : GeoNet reported that the minor ash and sulfur dioxide emissions from the active vent area in Whakaari/White Island’s crater only occurred on 18 September based on subsequent webcam and satellite images. The most likely cause for the emission was a gas release from small amount of magma moving into the shallow part of the volcano, though there was no evidence of increasing activity at the volcano.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 28 September – 4 October 2022

Alaid – Kuril Islands (Russia) : KVERT reported that a thermal anomaly over Alaid was identified in satellite images during 22-30 September. Ash plumes were visible drifting 140 km NE and SE during 26-27 September.

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 4 October. Daily counts of eruptive events producing gas-and-steam plumes were variable, though during the middle of the week they had decreased to less than 10 events per day. By 1040 on 28 September the dimensions of the new island were estimated to be 268 m N-S and 283 m E-W, and the highest point on the island was about 15 m a.s.l. The island was surrounded by plumes of discolored water within about 200 m from the shore. The plumes were elongated to the S, and were denser with suspended material within 1 km and more diffuse at distances greater or equal to 2 km. Mariners were advised to stay 4 km away from the volcano.

Nishinoshima – Izu Islands : According to JMA and the Tokyo VAAC an eruption at Nishinoshima produced ash plumes that rose to 1.8-2.6 km (6,000-8,500 ft) a.s.l. and drifted E and W during 1-4 October.

Piton de la Fournaise – Reunion Island (France) : OVPF reported that the eruption at Piton de la Fournaise that began on 19 September was ongoing at a cone adjacent to the SW flank of Piton Kala Pélé during 28 September-4 October. The cone ejected lava to low heights above the rim. Lava flowed from the base of the cone in two main branches, to the SE and E, mainly through lava tubes, as far as 3 km. By 28 September the cone had grown to just over 8 m tall and around 27 m wide at its base. Average daily lava flow discharge rate estimates had a mean value of 8 meters per second at the beginning of the eruption but then stabilized at 2-4 meters per second; the flow rate increased during 28-29 September to more than 6 meters per second. Lava discharge rates were likely underestimated due to measurements hindered by weather conditions or flows obscured by tubes. Tremor levels and gas emissions also began increasing on 29 September and remained at high levels during the rest of the week. The vent at the top of the cone widened and a new, smaller cone formed on the S flank and produced lava flows. The volume of erupted lava was 2.6-5.4 million cubic meters by 30 September; peak discharge rates reached 20 meters per second at times. Sulfur dioxide emission estimates derived from satellite data had increased from about 610 tons per day on 28 September to 1,525 tons per day on 1 October. A well-defined gas plume, denser than those seen during previous days, was identified in a 30 September satellite image drifting 300 km NW at an altitude of 3 km (10,000 ft) a.s.l. A more significant sulfur dioxide plume was identified in satellite data the next day, drifting as far as 400 km. Gas plumes drifted SW during 2-3 October. Sulfur dioxide emissions continued to increase and were about 2,500 tons per day on 3 October. The cone had grown to around 12 m tall and 43 m wide at the base. During 3-4 October the ejection of lava above the cone became less intense, and the new smaller cone was only weakly active. The southernmost lava flow had reached 1,800 m elevation in an area 1.5 km NW of Nez coupé du Tremblet. During 4-5 October tremor levels fluctuated. Lava effusion increased, averaging 10 meters per second with peaks at 25 meters per second. Lava was ejected above the main vent, which was 23 m wide; the smaller vent was not active. The eruption stopped or paused at 0748 on 5 October based on visual observations and a sudden halt in tremor signals.

Trident – Alaska : A swarm began on 24 August and within about four days the seismic network began detecting episodes of weak seismic tremor and low frequency earthquakes. The events were initially located at depths around 25 km, but then they progressively shallowed to around 5 km by 28 August. Earthquakes were located 3-6 km deep since then, though some deeper events were recorded. AVO attributed the swarm to moving magma or magmatic fluids and noted that seismic swarms had previously been recorded with no subsequent eruptions.

Environment

Temporary Island

The recent eruption of an undersea volcano in Tonga created a new, small landmass that has grown to about 15 metres in height, covering about 3.6 hectares. The new island, in an area known as Home Reef, is not expected to withstand the waves and wind of the South Pacific for very long.

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Volcanos

Roundup of Global Volcanic Activity – Ongoing Activity for the week 21 September – 27 September 2022

Aira – Kyushu (Japan) : JMA reported that six eruptive events and three explosions at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) were recorded during 19-26 September. Volcanic plumes rose as high as 2.4 km above the crater rim and large blocks were ejected as far as 700 m from the vent. Incandescence at the crater was visible nightly. Sulfur dioxide emissions were somewhat high at 1,900 tons per day on 22 September. Nighttime incandescence at the crater was visible during 2-16 September. A notable eruptive event at 1335 on 23 September generated an ash plume that rose 1.7 km above the crater rim and also drifted down-flank to the SE until 1600. A large amount of ashfall was deposited on the SE flank.

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 E. A thermal anomaly over the volcano was identified in satellite images on 18 September. Ash fell in Severo-Kurilsk during 20-22 September.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin likely continued during 20-27 September. Elevated surface temperatures were identified during 20-21 September; weather clouds often prevented webcam and satellite views during the rest of the week. A data outage that affected the local seismic network was resolved by 23 September. Seismicity was low during 24-25 September.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Karymsky was identified in satellite images during 16-18 and 20-21 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 20-27 September, entering the lava lake and flowing onto the crater floor. The continuously active part of the lake dropped 10 m, regained 3 m during 19-22 September, and then was unchanged the rest of the week. Breakouts of lava occurred at the W and N margins of the lake during most of the week.

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 460 km SE during 21-22 September.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 20-27 September. Daily white emissions rose as high as 350 m above the summit and drifted in multiple directions. At 0350 on 23 September an eruptive event produced an ash plume that rose 800 m and drifted W. An image captured at that time showed Strombolian activity with incandescent material being ejected above the summit. White-and-gray plumes generally rose as high 500 m and drifted NW, W, and S that same day.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 16-22 September and seismicity remained at high 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 1.9 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 20-27 September. Small explosions were detected in seismic and infrasound data during 20-21 September; seismic tremor levels were variable during the rest of the week. Weather clouds often prevented views of the volcano, though elevated surface temperatures were identified in satellite and webcam images during 20-21 and 23-27 September. A diffuse gas was occasionally seen in webcam images during 25-26 September, and one plume with possible ash content was visible during 26-27 September.

Pinatubo – Luzon (Philippines) : On 25 September PHIVOLCS warned of potential lahars around Pinatubo due to intense rains from a typhoon expected during 25-26 September. Significant deposits from 1991 pyroclastic density currents on the W flank may be remobilized, generating lahars down major drainages in that watershed. PHIVOLCS noted that the communities of San Marcelino, San Narciso, San Felipe, and Botolan, Zambales Province, and communities in Tarlac and Pampanga Provinces may be affected by lahars and flooding.

Reventador – Ecuador : IG characterized the ongoing eruption at Reventador as moderate during 20-27 September. Gas, steam, and ash plumes, observed with webcams or reported by the Washington VAAC, rose as high as 1.3 km above the summit and drifted SW, W, NW, and NE. Crater incandescence was visible nightly; the lava flow on the NE flank continued to be active, and incandescent blocks were visible rolling 600-800 m down the flanks during 20-23 and 26-27 September.

Sangay – Ecuador : IG reported a high level of activity at Sangay during 20-27 September. Daily seismic counts ranges were 702-1,152 explosions, 12-105 long-period events, and 9-95 tremor events indicating emissions. Daily ash-and-gas plumes were identified in IG webcam images and visible in satellite images according to the Washington VAAC. Plumes generally rose as high as 2 km above the volcano but during 25-27 September they rose as high as 3 km. The plumes drifted mostly W and NW, but some drifted SW, N, and NE. Daily thermal anomalies were identified in satellite images. Ashfall was reported in the Chauzán sector, Chimborazo province, during 22-23 September.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 20-27 September. Eruptive events on 24 September (at 0606) and 27 September (at 0517 and 0651) produced ash plumes that rose 400-500 m above the summit and drifted W and SW.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that the eruption at Semisopochnoi was ongoing during 13-20 September. Seismicity remained elevated with intermittent periods of low-amplitude tremor. Steam emissions from the active vent in the N crater of Mount Cerebus were visible in webcam views on most days.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that the ongoing eruption at Sheveluch was characterized by explosions, hot avalanches, and lava-dome extrusion during 15-22 September. A daily thermal anomaly was identified in satellite images. Plumes of re-suspended ash drifted 430 km E during 17-18 and 21-22 September.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the eruption at Suwanosejima’s Ontake Crater continued during 19-26 September. A total of 19 explosions produced eruption plumes that rose as high as 2 km above the crater rim. Crater incandescence was visible nightly and ash fell in Toshima village (3.5 km SSW).

Taal – Luzon (Philippines) : On 25 September PHIVOLCS warned of potential lahars around Taal due to intense rains from a typhoon expected during 25-26 September, with a particular focus on the western part of the caldera where ash deposits could become remobilized and affect the communities of Agoncillo and Laurel, Batangas Province. The report also warned that the ground cracks formed during the 2020 eruption on the NE and SW sectors of Taal Caldera may become enlarged or eroded and cause damage to buildings and houses. The ground cracks were located in the municipalities of Agoncillo, San Nicolas, Lemery, and Taal on the SW part of the caldera, and in the cities of Talisay and Tanauan on the NE side.

Volcanos

Roundup of Global Volcanic Activity – New Activity for the week 21 September – 27 September 2022

Alaid – Kuril Islands (Russia) : KVERT reported that a thermal anomaly over Alaid was identified in satellite images during 15-22 September. On 18 September an ash plume drifted 50 km E.

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 27 September. The eruption continued at variable intensities, mainly producing daily plumes of gas and steam that rose no higher than 2 km above sea level. During 0040-0250 on 25 September steam-and-ash plumes rose 2-4 km a.s.l. and drifted 30 km W, S, and SE. At 0030 on 27 September an ash plume rose 6-8 km a.s.l. and drifted 25 km SSE. The island was surrounded by plumes of discolored water.

Piton de la Fournaise – Reunion Island (France) : OVPF reported that the eruption at Piton de la Fournaise that began on 19 September, E of Piton Kala Pélé, was ongoing during 21-27 September. Gas plumes drifted SW, WSW, W, NNW, and were detected as far as 200 km from the vent in a 27 September satellite image. The active cone on the low end of the fissure ejected lava to low heights above the cone’s rim. Lava flows from the base of the cone formed two main flows that traveled SE and ESE. Lava flowed through sections of tubes mainly located along the first kilometer of both flows. Average daily lava-flow rate estimates varied from 1 to 8 meters per second based on satellite data. The SE flow front had advanced to the Château Fort crater area, reaching 2,000 m elevation on 24 September, though that flow had stopped advancing by 26 September. The eruption was confined to the caldera.

Taupo – North Island (New Zealand) : On 28 September GeoNet reported that seismic unrest and deformation at Taupo continued during the previous week. About 750 earthquakes have been located at depths of 4-13 km beneath the lake since unrest began in May. During the past week the locations were concentrated beneath the E part of the lake and occurred at a slightly lower rate than the week before. 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 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.

Volcanos

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

Aira – Kyushu (Japan) : JMA reported that 10 explosions at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) were recorded during 12-19 September. Volcanic plumes produced by the explosions rose as high as 1.6 km above the crater rim and ballistics were ejected as far as 1.3 km from the vent. Sulfur dioxide emissions were high at 2,400 tons per day on 24 September. Nighttime incandescence at the crater was visible during 2-16 September.

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 3.6 km (11,800 ft) a.s.l. and drifted in multiple directions. A thermal anomaly over the volcano was identified in satellite images during 8 and 12-13 September. Ash fell in Severo-Kurilsk during 9-10 September.

Fagradalsfjall – Iceland : IMO stated that the Fagradalsfjall and Krýsuvík-Trölladyngja volcanic systems have been designated as two separate systems based on previous scientific research combined with data collected and analyzed from the two recent eruptions (2021 and 2022). On 15 September lava from the fissure that opened in Meradalir stopped erupting on 21 August. Seismicity remained at low levels and no deformation was detected.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin likely continued during 13-20 September, an analysis confirmed by clear satellite images during 13-15 September. Lava flowed outward from the vent area but flows at the margins did not advance. Minor steam emissions were also visible during 13-14 September and elevated surface temperatures were identified during 13-15 and 17-18 September. Weather cloud cover occasionally prevented webcam and satellite views. A data outage affected the local seismic network during 16-20 September, though no significant activity was detected on regional geophysical networks.

Ibu – Halmahera : PVMBG reported that the eruption at Ibu continued during 14-20 September. Gray-and-white ash plumes of variable densities rose as high as 800 m 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 18 September multiple, discrete, ash plumes from Kadovar rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted NW and WNW.

Karymsky – Eastern Kamchatka (Russia) : KVERT reported that a weak thermal anomaly over Karymsky was identified in satellite images during 9 and 10-11 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 13-20 September, entering the lava lake and flowing onto the crater floor. Part of the lake’s surface was continuously active.

Krysuvik-Trolladyngja – Reykjanes Peninsula : IMO stated that the Fagradalsfjall and Krýsuvík-Trölladyngja volcanic systems have been designated as two separate systems based on previous scientific research combined with data collected and analyzed from the two recent eruptions (2021 and 2022). On 15 September the Aviation Color Code for Krýsuvík-Trölladyngja was changed to Green, reflecting that the activity was at known background levels.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok continued during 13-20 September. Daily white emissions rose as high as 300 m above the summit and drifted in multiple directions. During 16-19 September white-and-gray or white, gray, and black plumes rose as high 1 km and drifted W and NW. Incandescence above the crater rim was visible in some webcam photographs posted during 14-15 September.

Merapi – Central Java : BPPTKG reported that the eruption at Merapi continued during 9-15 September and seismicity remained at high 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 1.8 km. No morphological changes to the SW and central lava domes were evident in photographs.

Nevados de Chillan – Central Chile : SERNAGEOMIN reported that a long-period earthquake signals were recorded at Nevados de Chillán at 0750 and 1913 on 19 September. Associated emissions at 0750 rose 1.1 km above the summit and drifted NE, and at 1913 rose 1.7 km above the summit and drifted SE. The Alert Level remained at Yellow, the second lowest level on a four-color scale, and residents were reminded not to approach the crater within 3 km.

Pavlof – Alaska Peninsula, Alaska : AVO reported that a minor eruption at a vent on Pavlof’s upper E flank was ongoing during 13-20 September. Seismic tremor persisted. New lahar and minor ash deposits extending less than 900 m from the vent were visible during 11-13 September. Strong incandescence at the vent and from an area within 200 m downslope was visible in webcam images starting on 14 September, signifying the emplacement of a short lava flow. Elevated surface temperatures over the vent and flow were identified in satellite images through 20 September; lava effusion continued but no active lava flows extended down the flank from the vent. Explosions were recorded during 18-19 September and steam emissions were visible in webcam images during 19-20 September.

Purace – Colombia : Observatorio Vulcanológico y Sismológico de Popayán, Servicio Geologico Colombiano (SGC), reported that during 13-19 September the number of earthquakes at Puracé was slightly higher compared to previous weeks. A seismic swarm was recorded on 15 September. Events were located about 1.5 km SW of Puracé crater, at depths of 3-4 km, and were as large as M 1.3. A total of 904 earthquakes were recorded during the week; 296 of those were volcano-tectonic events, 538 were long-period events, 54 were low-energy pulses of tremor, 11 were tornillo-type events, and five were hybrid events. Data from the GNSS (Global Navigation Satellite System) geodetic network indicated continuing inflation. White gas plumes were visible in the Anambío, Mina, Lavas Rojas, Cerro Sombrero, and Curiquinga webcams drifting NW. Sulfur dioxide emissions were as high as 2,021 tonnes per day.

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 explosion at 0147 on 14 September produced a steam-and-gas plume that rose 600 m above the crater rim. Low-frequency tremor began at 0900 on 17 September and was possibly associated with small eruptive events, though they were not visually confirmed. A possible emission was recorded at 0219.

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 13-20 September. Eruptive events at 0524 on 17 September and 0505 on 19 September produced ash plumes that rose 500 m above the summit and drifted W and SW. 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.

Semisopochnoi – Aleutian Islands (USA) : AVO reported that the eruption at Semisopochnoi was ongoing during 13-20 September. Seismicity remained elevated and characterized by intermittent tremor. Low-level ash emissions from the N crater of Mount Cerberus were occasionally visible in mostly cloudy webcam views during 13-15 September. Possible fresh local ashfall was seen in webcam images during 16-17 September. Steam emissions were visible in webcam views during 19-20 September.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that the ongoing eruption at Sheveluch was characterized by explosions, hot avalanches, and lava-dome extrusion during 8-15 September. A daily thermal anomaly was identified in satellite images. Plumes of re-suspended ash drifted 90 km E on 8 September.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the eruption at Suwanosejima’s Ontake Crater continued during 12-19 September. A total of 11 explosions produced eruption plumes that rose as high as 1.4 km above the crater rim and ejected large blocks 600 m from the vent. Volcanic tremor was occasionally recorded.

Whakaari/White Island – North Island (New Zealand) : GeoNet reported that minor ash emissions from the active vent area in Whakaari/White Island’s crater were visible in webcam images on 18 September. The Aviation Color Code was raised to Orange; the Volcanic Alert Level remained at 2. Minor light brown ash emissions were visible through the day, and rose no higher than 600 m above the volcano. Ash emissions were not visible beyond the island, but a steam plume was seen from the Bay of Plenty coast. A strong sulfur dioxide signal associated with the emissions was identified in satellite images that same day. One of the seismic stations began working again on 19 September and showed typical low-level seismicity, consistent with no visible ash emissions. GeoNet was unable to accurately characterize the ash emissions due to the lack of data from inoperable instruments and the semi-operational webcam on the island. They noted that the most likely cause was a small amount of magma moving into the shallow part of the volcano.

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.