4-4-4-4-4-4-4-4-4-4-4-4-4 From: "Kuhn, Sally" <KUHNS@xxxxxx> New Activity/Unrest: Ioto, Japan | Kanlaon, Philippines | Karymsky, Russia | Lokon-Empung, Indonesia | Whakaari/White Island, New Zealand Ongoing Activity: Aira, Japan | Bur ni Telong, Indonesia | Dukono, Indonesia | Great Sitkin, United States | Home Reef, Tonga | Ibu, Indonesia | Kilauea, United States | Kirishimayama, Japan | Krasheninnikov, Russia | Kuchinoerabujima, Japan | Lewotobi, Indonesia | Lewotolok, Indonesia | Marapi, Indonesia | Mayon, Philippines | Merapi, Indonesia | Poas, Costa Rica | Popocatepetl, Mexico | Santa Maria, Guatemala | Semeru, Indonesia | Sheveluch, Russia | Suwanosejima, Japan The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday, these reports are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of all of Earth's volcanoes erupting during the week, but rather a summary of activity at volcanoes that meet criteria discussed in detail in the "Criteria and Disclaimers" section. Carefully reviewed, detailed reports about recent activity are published in issues of the Bulletin of the Global Volcanism Network. Note that many news agencies do not archive the articles they post on the Internet, and therefore the links to some sources may not be active. To obtain information about the cited articles that are no longer available on the Internet contact the source. New Activity/Unrest Ioto | Japan | 24.751°N, 141.289°E | Summit elev. 169 m The Japan Meteorological Agency (JMA) reported that an eruption at Ioto (Iwo-jima) began at around 1914 on 1 September from a submarine vent off the W coast of the island. An eruption plume rose about 1 km above the surface of the water and had darker- and lighter-colored components. The eruption was ongoing at least through the next day; a webcam image captured at 0730 on 2 September showed a Surtseyan ejection of dark material above the waterâ??s surface and a white steam-and-gas plume drifting downwind. The Japan Coast Guard reported bubbling water around the vents on 14 August, and JMA noted that both seismicity and inflation increased on 30 August. The last eruption occurred in February. Geologic Summary. Ioto, in the Volcano Islands of Japan, lies within a 9-km-wide submarine caldera. The volcano is also known as Ogasawara-Iojima to distinguish it from several other "Sulfur Island" volcanoes in Japan. The triangular, low-elevation, 8-km-long island narrows toward its SW tip and has produced trachyandesitic and trachytic rocks that are more alkalic than those of other volcanoes in this arc. The island has undergone uplift for at least the past 700 years, accompanying resurgent doming of the caldera; a shoreline landed upon by Captain Cook's surveying crew in 1779 is now 40 m above sea level. The Motoyama plateau on the NE half of the island consists of submarine tuffs overlain by coral deposits and forms the island's high point. Many fumaroles are oriented along a NE-SW zone cutting through Motoyama. Numerous recorded phreatic eruptions, many from vents on the W and NW sides of the island, have accompanied the uplift. Sources: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeXTf1oHqw$> ; Japan Coast Guard http://www.kaiho.mlit.go.jp/index.html <https://urldefense.com/v3/__http://www.kaiho.mlit.go.jp/index.html__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeWqYP6yMQ$> Kanlaon | Philippines | 10.4096°N, 123.13°E | Summit elev. 2422 m The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported continuing unrest and an ash emission at Kanlaon during 2-10 September. The seismic network recorded 0-7 daily volcanic earthquakes and daily sulfur dioxide emissions ranged from 762 to 1,922 tonnes per day. Gas-and-steam emissions of variable densities rose 75-700 m above the crater rim and drifted N, NW, and WSW. A period of diffuse ash emissions began at 1725 on 8 September and lasted about 55 minutes, producing low ash plumes that drifted WSW. At 0510 on 10 September an ash plume rose 600 m above the crater rim. The Alert Level remained at 2 (on a scale of 0-5); the public was warned to stay out of the 4-km-radius Permanent Danger Zone (PDZ) and pilots were advised to avoid flying close to the summit. Geologic Summary. Kanlaon volcano (also spelled Canlaon) forms the highest point on the Philippine island of Negros. The massive andesitic stratovolcano is covered with fissure-controlled pyroclastic cones and craters, many of which are filled by lakes. The largest debris avalanche known in the Philippines traveled 33 km SW from Kanlaon. The summit contains a 2-km-wide, elongated northern caldera with a crater lake and a smaller but higher active vent, Lugud crater, to the south. Eruptions recorded since 1866 have typically consisted of phreatic explosions of small-to-moderate size that produce minor local ashfall. Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS) http://www.phivolcs.dost.gov.ph/ <https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeV5bo4RNQ$> Karymsky | Russia | 54.049°N, 159.443°E | Summit elev. 1513 m The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that moderate activity continued at Karymsky during 28 August-4 September. A daily weak thermal anomaly was identified in satellite images. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates and times are provided in Coordinated Universal Time (UTC); specific events are indicated in local time where specified. Geologic Summary. Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed during the early Holocene. The caldera cuts the south side of the Pleistocene Dvor volcano and is located outside the north margin of the large mid-Pleistocene Polovinka caldera, which contains the smaller Akademia Nauk and Odnoboky calderas. Most seismicity preceding Karymsky eruptions originated beneath Akademia Nauk caldera, located immediately south. The caldera enclosing Karymsky formed about 7600-7700 radiocarbon years ago; construction of the stratovolcano began about 2000 years later. The latest eruptive period began about 500 years ago, following a 2300-year quiescence. Much of the cone is mantled by lava flows less than 200 years old. Historical eruptions have been vulcanian or vulcanian-strombolian with moderate explosive activity and occasional lava flows from the summit crater. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://kvert.febras.net/ <https://urldefense.com/v3/__http://kvert.febras.net/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeXydHi-Fw$> Lokon-Empung | Indonesia | 1.3644°N, 124.7992°E | Summit elev. 1580 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported continuing unrest at Lokon-Empung during 3-9 September. Seismicity continued to be elevated. Daily white steam-and-gas plumes rose as high as 100 m above the Tompaluan Crater rim and drifted in multiple directions. The plumes were characterized as white and gray on 4 September. According to news articles and PVMBG incandescence at the crater was visible in webcam images during 4-9 September. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 2.5 km away from Tompaluan Crater. Geologic Summary. The Lokong-Empung volcanic complex, rising above the plain of Tondano in North Sulawesi, includes four peaks and an active crater. Lokon, the highest peak, has a flat craterless top. The morphologically younger Empung cone 2 km NE has a 400-m-wide, 150-m-deep crater that erupted last in the 18th century. A ridge extending 3 km WNW from Lokon includes the Tatawiran and Tetempangan peaks. All eruptions since 1829 have originated from Tompaluan, a 150 x 250 m crater in the saddle between Lokon and Empung. These eruptions have primarily produced small-to-moderate ash plumes that sometimes damaged croplands and houses, but lava-dome growth and pyroclastic flows have also occurred. Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeUtATn4vw$> ; Antara News https://www.antaranews.com/berita/5092565/pos-pga-sebut-sinar-api-muncul-dari-kawah-tompaluan-gunung-lokon <https://urldefense.com/v3/__https://www.antaranews.com/berita/5092565/pos-pga-sebut-sinar-api-muncul-dari-kawah-tompaluan-gunung-lokon__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeW0Dlzipg$> Whakaari/White Island | New Zealand | 37.52°S, 177.18°E | Summit elev. 294 m GeoNet conducted an overflight at Whakaari/White Island a few days after ash plumes were observed in webcam views. During an overflight on 3 September scientists observed no ash in the steam-and-gas plumes rising from the active vents. Thin ashfall deposits from a brief eruption on 28 August were present on the island, though the active vent area was unchanged. Temperatures at the vents were around 164 degrees Celsius which was typical during periods of unrest. Measurements collected during overflights and from satellite data confirmed that gas output was steady and at levels consistent with minor activity. An area called Fumarole 0 on the S side of the main crater had dried out and an inclined vent was newly active. Several vents were active in the Fumarole 13/14 area on the N side of the main crater. The Volcanic Alert Level remained at 2 (on a scale of 0-5) and the Aviation Color Code remained at Yellow (the second lowest level on a four-color scale). Geologic Summary. The uninhabited Whakaari/White Island is the 2 x 2.4 km emergent summit of a 16 x 18 km submarine volcano in the Bay of Plenty about 50 km offshore of North Island. The island consists of two overlapping andesitic-to-dacitic stratovolcanoes. The SE side of the crater is open at sea level, with the recent activity centered about 1 km from the shore close to the rear crater wall. Volckner Rocks, sea stacks that are remnants of a lava dome, lie 5 km NW. Descriptions of volcanism since 1826 have included intermittent moderate phreatic, phreatomagmatic, and Strombolian eruptions; activity there also forms a prominent part of Maori legends. The formation of many new vents during the 19th and 20th centuries caused rapid changes in crater floor topography. Collapse of the crater wall in 1914 produced a debris avalanche that buried buildings and workers at a sulfur-mining project. Explosive activity in December 2019 took place while tourists were present, resulting in many fatalities. The official government name Whakaari/White Island is a combination of the full Maori name of Te Puia o Whakaari ("The Dramatic Volcano") and White Island (referencing the constant steam plume) given by Captain James Cook in 1769. Source: GeoNet http://www.geonet.org.nz/ <https://urldefense.com/v3/__http://www.geonet.org.nz/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeXt1FISFw$> Ongoing Activity Aira | Japan | 31.5772°N, 130.6589°E | Summit elev. 1117 m The Japan Meteorological Agency (JMA) reported ongoing eruptive activity at Minamidake Crater (Aira Calderaâ??s Sakurajima volcano) during 1-8 September. Nightly crater incandescence was visible in webcam images. Sulfur dioxide emissions were characterized as slightly high, averaging 1,900 tons per day on 5 September. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to be cautious within 2 km of both the Minimadake and Showa craters. Geologic Summary. The Aira caldera in the northern half of Kagoshima Bay contains the post-caldera Sakurajima volcano, one of Japan's most active. Eruption of the voluminous Ito pyroclastic flow accompanied formation of the 17 x 23 km caldera about 22,000 years ago. The smaller Wakamiko caldera was formed during the early Holocene in the NE corner of the caldera, along with several post-caldera cones. The construction of Sakurajima began about 13,000 years ago on the southern rim and built an island that was joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kitadake summit cone ended about 4,850 years ago, after which eruptions took place at Minamidake. Frequent eruptions since the 8th century have deposited ash on the city of Kagoshima, located across Kagoshima Bay only 8 km from the summit. The largest recorded eruption took place during 1471-76. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeXTf1oHqw$> Bur ni Telong | Indonesia | 4.769°N, 96.821°E | Summit elev. 2617 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported decreased seismicity at Bur ni Telong. Increases in both deep and shallow volcanic earthquakes were recorded in July and early August, though through late August only the number of deep volcanic earthquakes continued to be elevated. Seismicity decreased during 1-7 September. No emissions were observed. The Alert level was lowered to 1 (on a scale from 1 to 4) at 0900 on 8 September and the public was advised to not spend the night in the crater area and to avoid fumaroles and solfataras during cloudy or rainy weather. Geologic Summary. The conical Bur ni Telong volcano was constructed at the southern base of the massive Bur ni Geureudong volcanic complex, one of the largest in northern Sumatra. The historically active volcano lies 4.5 km from the summit of Geureudong,and its summit crater has migrated to the ESE, leaving arcuate crater rims. Lava flows are exposed on the southern flank. Explosive eruptions were recorded during the 19th and 20th centuries. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeUtATn4vw$> Dukono | Indonesia | 1.6992°N, 127.8783°E | Summit elev. 1273 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Dukono continued during 27 August-2 September. White-and-gray gas-and-ash plumes rose as high as 700 m above the summit and drifted NW, W, and SW. Emissions were not visible on 6 September. The Alert Level remained at Level 2 (on a scale of 1-4) and the public was warned to stay 4 km away from the Malupang Warirang Crater. Geologic Summary. The Dukono complex in northern Halmahera is on an edifice with a broad, low profile containing multiple peaks and overlapping craters. Almost continuous explosive eruptions, sometimes accompanied by lava flows, have occurred since 1933. During a major eruption in 1550 CE, a lava flow filled in the strait between Halmahera and the Gunung Mamuya cone, 10 km NE. Malupang Wariang, 1 km SW of the summit crater complex, contains a 700 x 570 m crater that has also had reported eruptions. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeUtATn4vw$> Great Sitkin | United States | 52.076°N, 176.13°W | Summit elev. 1740 m The Alaska Volcano Observatory (AVO) reported that slow lava effusion continued to feed a thick flow in Great Sitkinâ??s summit crater during 2-9 September. Satellite data indicated that the flow was advancing S, with some rockfalls occurring along the S and E margins. A field crew conducted an overflight of the volcano on 2 September and photographed the active lava flow. The SE half of the lava dome appeared to be inflating. Small daily earthquakes were detected by the seismic network, including signals probably caused by the small rockfalls. Weather clouds sometimes obscured satellite and webcam views; minor steam emissions from the lava dome were observed in webcam images during 3-4 September and elevated surface temperatures were identified in satellite data during 6-7 September. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale). Geologic Summary. The Great Sitkin volcano forms much of the northern side of Great Sitkin Island. A younger volcano capped by a small, 0.8 x 1.2 km ice-filled summit caldera was constructed within a large late-Pleistocene or early Holocene scarp formed by massive edifice failure that truncated an older edifice and produced a submarine debris avalanche. Deposits from this and an even older debris avalanche from a source to the south cover a broad area of the ocean floor north of the volcano. The summit lies along the eastern rim of the younger collapse scarp. Deposits from an earlier caldera-forming eruption of unknown age cover the flanks of the island to a depth up to 6 m. The small younger caldera was partially filled by lava domes emplaced in 1945 and 1974, and five small older flank lava domes, two of which lie on the coastline, were constructed along northwest- and NNW-trending lines. Hot springs, mud pots, and fumaroles occur near the head of Big Fox Creek, south of the volcano. Eruptions have been recorded since the late-19th century. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://avo.alaska.edu/ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeUQhPBpWw$> Home Reef | Tonga | 18.992°S, 174.775°W | Summit elev. -10 m The Tonga Geological Services reported no indications of activity at Home Reef during 16 August-1 September. A comparison of satellite images from 11 and 28 August showed minor to no visible changes. Both images showed a diffuse gas plume rising from the crater area and discolored water around the island. There were yellow sulfur deposits in and around the main crater. The dimensions of the main vent crater and of the island were unchanged; the main vent crater was about 210 m N-S and 120 m E-W and the island measured 550 x 420 m. The Aviation Color Code remained at Yellow (the second lowest level on a four-level scale, the Maritime Alert Level remained at Orange (the third level on a four-level scale) with advice to stay at least 2 nautical miles (3.7 km) from the island, and the Alert Level for residents of Vavaâ??u and Haâ??apai remained at Green (the first level on a four-level scale). Geologic Summary. Home Reef, a submarine volcano midway between Metis Shoal and Late Island in the central Tonga islands, was first reported active in the mid-19th century, when an ephemeral island formed. An eruption in 1984 produced a 12-km-high eruption plume, large amounts of floating pumice, and an ephemeral 500 x 1,500 m island, with cliffs 30-50 m high that enclosed a water-filled crater. In 2006 an island-forming eruption produced widespread dacitic pumice rafts that drifted as far as Australia. Another island was built during a September-October 2022 eruption. Source: Tonga Geological Services, Government of Tonga https://www.facebook.com/tongageologicalservice <https://urldefense.com/v3/__https://www.facebook.com/tongageologicalservice__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeVGhRV0nw$> Ibu | Indonesia | 1.4941°N, 127.6324°E | Summit elev. 1357 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that the eruption at Ibu continued during 3-9 September. Daily dense gray or white-and-gray ash plumes rose 400-1,000 m above the summit and drifted NW, W, and SW. Incandescence at the summit was visible in a few nighttime webcam images. The Alert Level remained at 2 (the second lowest level on a four-level scale) and the public was advised to stay 2 km away from the active crater and 3.5 km away from the N crater wall opening. Geologic Summary. The truncated summit of Gunung Ibu stratovolcano along the NW coast of Halmahera Island has large nested summit craters. The inner crater, 1 km wide and 400 m deep, has contained several small crater lakes. The 1.2-km-wide outer crater is breached on the N, creating a steep-walled valley. A large cone grew ENE of the summit, and a smaller one to the WSW has fed a lava flow down the W flank. A group of maars is located below the N and W flanks. The first observed and recorded eruption was a small explosion from the summit crater in 1911. Eruptive activity began again in December 1998, producing a lava dome that eventually covered much of the floor of the inner summit crater along with ongoing explosive ash emissions. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeUtATn4vw$> Kilauea | United States | 19.421°N, 155.287°W | Summit elev. 1222 m The Hawaiian Volcano Observatory (HVO) reported that the eruption within Kilaueaâ??s Kaluapele summit caldera, characterized by episodic fountaining, incandescence, and intermittent spatter at vents with craters along the SW margin of Halemaâ??umaâ??u Crater, continued at variable levels during 3-9 September. Patterns of tremor indicated that gas pistoning was likely occurring deeper within the vent and was characterized by low-frequency bursts every 1-8 minutes. Elevated levels of gas continued to be emitted from the vent area. Minor incandescence at the N vent and from areas on the lava-flow field were intermittently visible during 3-5 September. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale). Geologic Summary. Kilauea overlaps the E flank of the massive Mauna Loa shield volcano in the island of Hawaii. Eruptions are prominent in Polynesian legends; written documentation since 1820 records frequent summit and flank lava flow eruptions interspersed with periods of long-term lava lake activity at Halemaumau crater in the summit caldera until 1924. The 3 x 5 km caldera was formed in several stages about 1,500 years ago and during the 18th century; eruptions have also originated from the lengthy East and Southwest rift zones, which extend to the ocean in both directions. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1,100 years old; 70% of the surface is younger than 600 years. The long-term eruption from the East rift zone between 1983 and 2018 produced lava flows covering more than 100 km2, destroyed hundreds of houses, and added new coastline. Source: US Geological Survey Hawaiian Volcano Observatory (HVO) https://volcanoes.usgs.gov/observatories/hvo/ <https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeU0V1-Yqw$> Kirishimayama | Japan | 31.934°N, 130.862°E | Summit elev. 1700 m The Japan Meteorological Agency (JMA) reported that activity continued at Shinmoedake (Shinmoe peak, a stratovolcano of the Kirishimayama volcano group) during 3-9 September. The number of volcanic earthquakes located beneath Shinmoedake, first detected in late October 2024, continued to be frequent; volcanic tremor was detected during 2-3 September. Eruptive events at 1127 and 1300 and a period of continuous ash emissions during 1330-1342 on 3 September produced ash plumes that rose as high as 2.3 km above the crater rim and drifted SW. Ash plumes from eruptive events at 1432 and 1556 later that day rose as high as 1.1 km above the crater rim and drifted SW. Ashfall reported in areas downwind, including in Kirishima City (21 km SW) and Miyakonojo City (30 km SE), obscured the lines on some roads. Continuous ash emissions during 0854-1000 on 5 September rose 100-200 m above the crater rim and drifted SE. At 0344 on 7 September an ash plume rose 100 m above the crater rim and drifted E. Continuous ash emissions during 2033-2231 on 7 September rose 100 m above the crater rim and drifted E. Fumarolic plumes rose as high as 10 m above the fissures on the W flank during 5-8 September. The Alert Level remained at 3 (on a 5-level scale) and the public was warned to exercise caution within 3 km from Shinmoedake Crater. Geologic Summary. Kirishimayama is a large group of more than 20 Quaternary volcanoes located north of Kagoshima Bay. The late-Pleistocene to Holocene dominantly andesitic group consists of stratovolcanoes, pyroclastic cones, maars, and underlying shield volcanoes located over an area of 20 x 30 km. The larger stratovolcanoes are scattered throughout the field, with the centrally located Karakunidake being the highest. Onamiike and Miike, the two largest maars, are located SW of Karakunidake and at its far eastern end, respectively. Holocene eruptions have been concentrated along an E-W line of vents from Miike to Ohachi, and at Shinmoedake to the NE. Frequent small-to-moderate explosive eruptions have been recorded since the 8th century. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeXTf1oHqw$> Krasheninnikov | Russia | 54.596°N, 160.27°E | Summit elev. 1816 m The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that the eruption at Krasheninnikov continued during 2-9 September. A daily thermal anomaly over the volcano was identified in satellite images. Dates and times are provided in Coordinated Universal Time (UTC); specific events are indicated in local time where specified. Geologic Summary. The late-Pleistocene to Holocene Krasheninnikov volcano is comprised of two overlapping stratovolcanoes within a 9 x 10 km Pleistocene caldera. Young lava flows from summit and flank vents descend both into the caldera and down its outer flanks, and older flows that covered much of the SE caldera rim extended downslope at least 7 km. Tephra deposits from the caldera-forming eruption directly overlie a 39,000 years before present (BP) tephra thought to be associated with the formation of Uzon caldera (Florenskii, 1988). The intra-caldera stratovolcanoes are situated along a NE-SW-trending fissure that has also produced zones of Holocene cinder cones extending 15-20 km beyond the caldera. Construction of the southern edifice began about 11,000 years BP and lasted for about 4,500 years; it has a summit crater about 800-900 m wide. The northern edifice was constructed during a cycle of similar length that began about 6,500 years ago; it has a summit crater about 1.5 km wide, within which is low cone with an 800-m-wide crater containing another small cone. An eruptive cycle during about 600-400 years BP (1350-1550 CE) produced the Pauk lava cone in the crater of the northern cone and the Yuzhny lava flow on SW flank outside the caldera, followed by the Molodoy flow from the upper SW flank (Ponomareva, 1987; Ponomareva and Tsyurupa, 1985; Ponomareva and Braitseva, 1990). Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://kvert.febras.net/ <https://urldefense.com/v3/__http://kvert.febras.net/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeXydHi-Fw$> Kuchinoerabujima | Japan | 30.443°N, 130.217°E | Summit elev. 657 m The Japan Meteorological Agency (JMA) reported that the number of shallow volcanic earthquakes at Kuchinoerabujima began to decline in July; they had been frequent since the beginning of April, with most epicenters located near Furudake Crater, and a few near Shindake Crater (just N of Furudake). No large-amplitude earthquakes were recorded. There were no notable changes to hydrothermal fields observed during 19-21 August. Sulfur dioxide gas emissions were at low levels, fluctuating between 20 and 70 tons per day, and no changes to white gas-and-steam emissions were observed. The Alert Level was lowered to 2 (on a scale of 1-5) at 1100 on 5 September and the public was warned to exercise caution within 1 km of both Shindake and Furudake craters and within 2 km W of Shindake Crater. Geologic Summary. A group of young stratovolcanoes forms the eastern end of the irregularly shaped island of Kuchinoerabujima in the northern Ryukyu Islands, 15 km W of Yakushima. The Furudake, Shindake, and Noikeyama cones were erupted from south to north, respectively, forming a composite cone with multiple craters. All historical eruptions have occurred from Shindake, although a lava flow from the S flank of Furudake that reached the coast has a very fresh morphology. Frequent explosive eruptions have taken place from Shindake since 1840; the largest of these was in December 1933. Several villages on the 4 x 12 km island are located within a few kilometers of the active crater and have suffered damage from eruptions. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeXTf1oHqw$> Lewotobi | Indonesia | 8.542°S, 122.775°E | Summit elev. 1703 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported increased seismic activity and deformation at Lewotobi Laki-laki during 30 August-6 September. The seismic network recorded a significant increase in the number of harmonic tremor earthquakes and deep volcanic earthquakes during 30 August-4 September and a shallow volcanic earthquake was detected on 5 September. Tiltmeter data indicated slow inflation over that same time, while GNSS (Global Navigation Satellite System) data indicated deflation; the deformation data suggested that the activity was occurring at shallow levels. On 6 September a period of continuous tremor was detected, indicating rising magma near the surface. At 1000 the Alert level was raised to 4 (the highest level on a scale of 1-4) and the exclusion zone was increased to 6 km from the center of Laki-laki and 7 km in a semicircle clockwise from the SW to the NE. At 1806 that same day a gray ash plume rose 1 km above the crater rim and drifted NW, W, and SW. White plumes rose as high as 1 km above the crater rim and drifted in multiple directions on 8 September and were not visible on 9 September. Geologic Summary. The Lewotobi edifice in eastern Flores Island is composed of the two adjacent Lewotobi Laki-laki and Lewotobi Perempuan stratovolcanoes (the "husband and wife"). Their summits are less than 2 km apart along a NW-SE line. The conical Laki-laki to the NW has been frequently active during the 19th and 20th centuries, while the taller and broader Perempuan has had observed eruptions in 1921 and 1935. Small lava domes have grown during the 20th century in both of the summit craters, which are open to the north. A prominent cone, Iliwokar, occurs on the E flank of Perampuan. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeUtATn4vw$> Lewotolok | Indonesia | 8.274°S, 123.508°E | Summit elev. 1431 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that an eruption at Lewotolok was ongoing during 3-9 September. White-to-gray ash plumes rose 100-600 m above the summit of the cone and drifted W and NW on most days; white plumes rose 50 m above the summit and drifted W and NW on 7 September. Several nighttime webcam images showed Strombolian ejections of incandescent material above the cone and onto the flanks. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 3 km away from the summit. Geologic Summary. The Lewotolok (or Lewotolo) stratovolcano occupies the eastern end of an elongated peninsula extending north into the Flores Sea, connected to Lembata (formerly Lomblen) Island by a narrow isthmus. It is symmetrical when viewed from the north and east. A small cone with a 130-m-wide crater constructed at the SE side of a larger crater forms the volcano's high point. Many lava flows have reached the coastline. Eruptions recorded since 1660 have consisted of explosive activity from the summit crater. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeUtATn4vw$> Marapi | Indonesia | 0.38°S, 100.474°E | Summit elev. 2885 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Marapi (on Sumatra) continued during 3-9 September. An eruptive event was recorded on 4 September, but weather conditions prevented visual confirmation. A dense gray ash plume rose 1.2 m above the crater rim ana drifted NE on 7 September and a dense gray-to-white ash plumes rose 1 km above the crater rim and drifted E on 8 September. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 3 km away from the active crater. Geologic Summary. Gunung Marapi, not to be confused with the better-known Merapi volcano on Java, is Sumatra's most active volcano. This massive complex stratovolcano rises 2,000 m above the Bukittinggi Plain in the Padang Highlands. A broad summit contains multiple partially overlapping summit craters constructed within the small 1.4-km-wide Bancah caldera. The summit craters are located along an ENE-WSW line, with volcanism migrating to the west. More than 50 eruptions, typically consisting of small-to-moderate explosive activity, have been recorded since the end of the 18th century; no lava flows outside the summit craters have been reported in historical time. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeUtATn4vw$> Mayon | Philippines | 13.257°N, 123.685°E | Summit elev. 2462 m The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported increased seismic activity at Mayon. During 0000-1730 on 6 September the seismic network recorded 26 volcanic earthquakes with local magnitudes of 0.4-2.7 which were located 5-10 km beneath the NE flank. Variable inflation had been detected at the NE sector since October 2024 and at the S and SW sectors since March 2025, based on continuous GPS, electronic tilt, and Electronic Distance Measurement (EDM) ground deformation data. Sulfur dioxide emissions remained near background levels, averaging 430 tonnes/day (t/d) in 2025, with the latest measurement of 609 t/d on 3 September. The Alert Level remained at 1 (on a 0-5 scale); the public was warned to stay out of the 6-km-radius Permanent Danger Zone (PDZ) and pilots were advised to avoid flying close to the summit. Geologic Summary. Symmetrical Mayon, which rises above the Albay Gulf NW of Legazpi City, is the most active volcano of the Philippines. The steep upper slopes are capped by a small summit crater. Recorded eruptions since 1616 CE range from Strombolian to basaltic Plinian, with cyclical activity beginning with basaltic eruptions, followed by longer periods of andesitic lava flows. Eruptions occur predominately from the central conduit and have also produced lava flows that travel far down the flanks. Pyroclastic density currents and mudflows have commonly swept down many of the approximately 40 ravines that radiate from the summit and have often damaged populated lowland areas. A violent eruption in 1814 killed more than 1,200 people and devastated several towns. Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS) http://www.phivolcs.dost.gov.ph/ <https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeV5bo4RNQ$> Merapi | Indonesia | 7.54°S, 110.446°E | Summit elev. 2910 m The Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG) reported that the eruption at Merapi (on Java) continued during 29 August-4 September. Earthquakes were less intense compared to the previous week. The SW lava dome produced nine lava avalanches that traveled as far as 1.9 km SW down the Bebeng drainage, 19 that traveled as far as 1.8 km SW down the Krasak drainage, and 39 that traveled as far as 2 km W down the Sat/Putih drainage. Small morphological changes to the SW lava dome resulted from lava effusion and minor collapses. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-7 km away from the summit, based on location. Geologic Summary. Merapi, one of Indonesia's most active volcanoes, lies in one of the world's most densely populated areas and dominates the landscape immediately north of the major city of Yogyakarta. It is the youngest and southernmost of a volcanic chain extending NNW to Ungaran volcano. Growth of Old Merapi during the Pleistocene ended with major edifice collapse perhaps about 2,000 years ago, leaving a large arcuate scarp cutting the eroded older Batulawang volcano. Subsequent growth of the steep-sided Young Merapi edifice, its upper part unvegetated due to frequent activity, began SW of the earlier collapse scarp. Pyroclastic flows and lahars accompanying growth and collapse of the steep-sided active summit lava dome have devastated cultivated lands on the western-to-southern flanks and caused many fatalities. Source: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG) http://www.merapi.bgl.esdm.go.id/ <https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeWh20Th_g$> Poas | Costa Rica | 10.2°N, 84.233°W | Summit elev. 2697 m The Observatorio Vulcanológico y Sismológico de Costa Rica-Universidad Nacional (OVSICORI-UNA) reported continuing gas-and-steam emissions with occasional minor amounts of ash at Poás during 2-9 September. Weather conditions often obscured visual observations of the crater area. Gas emissions at Boca A continued to be hot, approaching 800 degrees Celsius. Variable incandescence at Boca A vent continued to be visible at night. The lake over Boca C continued to rise and was approaching the rim of Boca A. Small eruptive events were recorded at 1325 and 1332 on 3 September based on a slight increase in in the intensity of corresponding acoustic tremor; the events were not detected by the seismic network and not visually confirmed due to weather conditions. The events on 3 September also corresponded with increased sulfur dioxide emissions of around 1,500 tonnes per day (t/d) at 1325 and about 500 t/d at 1332. A low-energy eruptive event began at 1710 on 7 September and lasted about seven minutes based on infrasound data. The vent produced an ash emission, though weather conditions mostly obscured views, and there was intense rainfall in the afternoon of 7 September. An ash emission was visible in the late afternoon and sustained ash emissions occurred during 1900-2200. Sulfur dioxide emissions decreased from 600 tons per day (t/d) to 100 t/d during 6-9 September based on data from Differential Optical Absorption Spectroscopy (DOAS) and Multi-component Gas Analyzer System (Multi-GAS) stations. A seismic event at 0336 on 9 September was either associated with the rupture of the wall separating Boca A and Boca C, causing water to flood Boca A, or from the interaction of water and high temperatures. Eruptive events were not immediately generated from the water flooding into Boca A but occurred several hours later; at 1048 an energetic explosion ejected ash and ballistics 300 m above the crater rim and generated an ash, steam, and gas plume that rose 500 m above the crater rim and drifted W. The Volcanic Alert Level remained at 2 (the second lowest level on a four-level scale) and the Aviation Color Code remained at Yellow (the second lowest color on a four-color scale). Geologic Summary. The broad vegetated edifice of Poás, one of the most active volcanoes of Costa Rica, contains three craters along a N-S line. The frequently visited multi-hued summit crater lakes of the basaltic-to-dacitic volcano are easily accessible by vehicle from the nearby capital city of San José. A N-S-trending fissure cutting the complex stratovolcano extends to the lower N flank, where it has produced the Congo stratovolcano and several lake-filled maars. The southernmost of the two summit crater lakes, Botos, last erupted about 7,500 years ago. The more prominent geothermally heated northern lake, Laguna Caliente, is one of the world's most acidic natural lakes, with a pH of near zero. It has been the site of frequent phreatic and phreatomagmatic eruptions since an eruption was reported in 1828. Eruptions often include geyser-like ejections of crater-lake water. Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA) http://www.ovsicori.una.ac.cr/ <https://urldefense.com/v3/__http://www.ovsicori.una.ac.cr/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeWGj6bp8A$> Popocatepetl | Mexico | 19.023°N, 98.622°W | Summit elev. 5393 m The Centro Nacional de Prevención de Desastres (CENAPRED) reported that eruptive activity continued at Popocatépetl during 12-19 August. The seismic network recorded 9-39 long-period events per day, accompanied by steam-and-gas emissions with occasional minor ash content. In addition, the seismic network recorded daily periods of low-amplitude tremor, characterized by harmonic and high-frequency signals, lasting from seven hours and 44 minutes to just over 14 hours. According to the Washington VAAC an ash plume visible in a webcam image at 2018 on 6 September rose to 6.4 km (21,000 ft) a.s.l., or as high as 1 km above the summit, and drifted S. Ash plumes identified in webcam and satellite images during 8-9 September rose 5.8-6.4 km (19,000-21,000 ft) a.s.l. and drifted W, WSW, and SW. The Alert Level remained at Yellow, Phase Two (the middle level on a three-color scale) and the public was warned to stay 12 km away from the crater. Geologic Summary. Volcán Popocatépetl, whose name is the Aztec word for smoking mountain, rises 70 km SE of Mexico City to form North America's 2nd-highest volcano. The glacier-clad stratovolcano contains a steep-walled, 400 x 600 m wide crater. The generally symmetrical volcano is modified by the sharp-peaked Ventorrillo on the NW, a remnant of an earlier volcano. At least three previous major cones were destroyed by gravitational failure during the Pleistocene, producing massive debris-avalanche deposits covering broad areas to the south. The modern volcano was constructed south of the late-Pleistocene to Holocene El Fraile cone. Three major Plinian eruptions, the most recent of which took place about 800 CE, have occurred since the mid-Holocene, accompanied by pyroclastic flows and voluminous lahars that swept basins below the volcano. Frequent historical eruptions, first recorded in Aztec codices, have occurred since Pre-Columbian time. Sources: Centro Nacional de Prevencion de Desastres (CENAPRED) https://www.gob.mx/cenapred <https://urldefense.com/v3/__https://www.gob.mx/cenapred__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeX98Su0kQ$> ; Washington Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/messages.html <https://urldefense.com/v3/__http://www.ssd.noaa.gov/VAAC/messages.html__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeUXQZCfzg$> Santa Maria | Guatemala | 14.757°N, 91.552°W | Summit elev. 3745 m The Instituto Nacional de SismologÃa, VulcanologÃa, MeteorologÃa e HidrologÃa (INSIVUMEH) reported high levels of ongoing eruptive activity at Santa Mariaâ??s Santiaguito dome complex during 2-9 September, with continuing lava extrusion at Caliente dome. Daily explosions, 1-3 per hour when reported, generated gas-and-ash plumes that rose as high as 1 km above the dome and drifted as far as 20 km W, WSW, and SW. Effusion of blocky lava produced incandescent block avalanches that descended mainly the W and SW flanks; the collapsed material occasionally produced short pyroclastic flows that reached the base of the cone. Incandescence was visible at Caliente dome mostly during dark hours. During the early afternoon of 3 September heavy rainfall generated a minor lahar in the Cabello de Ã?ngel drainage (SSW) that carried blocks up to 3 m in diameter mixed with fine sediment, tree trunks, and branches. Another lahar descended the Tambor drainage (SSW) that carried blocks up to 1 m in diameter mixed with fine sediment, tree trunks, and branches. Both lahars were hot and had a sulfur odor. Ashfall was reported in local areas on several days downwind including San Marcos Palajunoj (8 km SW) and Loma Linda (7 km W). Geologic Summary. Symmetrical, forest-covered Santa MarÃa volcano is part of a chain of large stratovolcanoes that rise above the Pacific coastal plain of Guatemala. The sharp-topped, conical profile is cut on the SW flank by a 1.5-km-wide crater. The oval-shaped crater extends from just below the summit to the lower flank, and was formed during a catastrophic eruption in 1902. The renowned Plinian eruption of 1902 that devastated much of SW Guatemala followed a long repose period after construction of the large basaltic andesite stratovolcano. The massive dacitic Santiaguito lava-dome complex has been growing at the base of the 1902 crater since 1922. Compound dome growth at Santiaguito has occurred episodically from four vents, with activity progressing E towards the most recent, Caliente. Dome growth has been accompanied by almost continuous minor explosions, with periodic lava extrusion, larger explosions, pyroclastic flows, and lahars. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH) http://www.insivumeh.gob.gt/ <https://urldefense.com/v3/__http://www.insivumeh.gob.gt/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeW2hrswDw$> Semeru | Indonesia | 8.108°S, 112.922°E | Summit elev. 3657 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that activity continued at Semeru during 3-9 September, with multiple daily eruptive events recorded by the seismic network. White-and-gray or gray ash plumes rose 400-700 m above the summit and drifted in multiple direction on most days; emissions were not visible on 9 September. The Alert Level remained at 2 (the second lowest level on a scale of 1-4). The public was warned to stay at least 3 km away from the summit in all directions, 8 km from the summit to the SE, 500 m from the banks of the Kobokan drainage as far as 13 km from the summit, and to avoid other drainages including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards. Geologic Summary. Semeru, the highest volcano on Java, and one of its most active, lies at the southern end of a volcanic massif extending north to the Tengger caldera. The steep-sided volcano, also referred to as Mahameru (Great Mountain), rises above coastal plains to the south. Gunung Semeru was constructed south of the overlapping Ajek-ajek and Jambangan calderas. A line of lake-filled maars was constructed along a N-S trend cutting through the summit, and cinder cones and lava domes occupy the eastern and NE flanks. Summit topography is complicated by the shifting of craters from NW to SE. Frequent 19th and 20th century eruptions were dominated by small-to-moderate explosions from the summit crater, with occasional lava flows and larger explosive eruptions accompanied by pyroclastic flows that have reached the lower flanks of the volcano. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeUtATn4vw$> Sheveluch | Russia | 56.653°N, 161.36°E | Summit elev. 3283 m The Kamchatkan Volcanic Eruption Response Team (KVERT) reported continuing eruptive activity at Sheveluchâ??s â??300 years of RASâ?? dome on the SW flank of Old Sheveluch and at the Young Sheveluch dome during 28 August-4 September. Thermal anomalies over the domes were identified in satellite images on 29 August and during 1-3 September; weather clouds obscured views on the other days. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC; specific events are in local time where noted. Geologic Summary. The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1,300 km3 andesitic volcano is one of Kamchatka's largest and most active volcanic structures, with at least 60 large eruptions during the Holocene. The summit of roughly 65,000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera breached to the south. Many lava domes occur on its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large open caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka. Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://kvert.febras.net/ <https://urldefense.com/v3/__http://kvert.febras.net/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeXydHi-Fw$> Suwanosejima | Japan | 29.638°N, 129.714°E | Summit elev. 796 m The Japan Meteorological Agency (JMA) reported that eruptive activity at Suwanosejima's Ontake Crater continued during 1-8 September. Incandescence was observed nightly in webcam images. An explosion at 1047 on 1 September produced an ash plume that rose 1.8 km above the crater rim and drifted N. An eruptive event at 0516 on 2 September sent an ash plume 1.3 km above the crater rim that drifted NW, followed by a similar event the next day at 0833 on 3 September when a plume rose 1.2 km above the crater and drifted SW. Minor ashfall was reported in Toshima Village (3.5 km SSW) during the week. The Alert Level remained at 2 (the second level on a five-level scale) and the public was warned to be cautious within 1.5 km of the crater. Geologic Summary. The 8-km-long island of Suwanosejima in the northern Ryukyu Islands consists of an andesitic stratovolcano with two active summit craters. The summit is truncated by a large breached crater extending to the sea on the E flank that was formed by edifice collapse. One of Japan's most frequently active volcanoes, it was in a state of intermittent Strombolian activity from Otake, the NE summit crater, between 1949 and 1996, after which periods of inactivity lengthened. The largest recorded eruption took place in 1813-14, when thick scoria deposits covered residential areas, and the SW crater produced two lava flows that reached the western coast. At the end of the eruption the summit of Otake collapsed, forming a large debris avalanche and creating an open collapse scarp extending to the eastern coast. The island remained uninhabited for about 70 years after the 1813-1814 eruption. Lava flows reached the eastern coast of the island in 1884. Only about 50 people live on the island. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!dzvH27XkBjP359cTdPtVkF_a3H4ACDuQ0PlKeN0aKSXEfiEiyJjks-wzy7Tu8PatS7pVWPmvkZsGz7IcKeXTf1oHqw$> 4-4-4-4-4-4-4-4-4-4-4-4-4 ------------------------------ End of Volcano Digest - 11 Sep 2025 to 12 Sep 2025 (#2025-85) *************************************************************
