8-8-8-8-8-8-8-8-8-8-8-8-8 From: "Kuhn, Sally" <KUHNS@xxxxxx> Smithsonian / USGS Weekly Volcanic Activity Report 2-8 October 2024 Sally Sennert - Weekly Report Editor (kuhns@xxxxxx) URL: https://volcano.si.edu/reports_weekly.cfm <https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hMUw4TaEg$> New Activity/Unrest: Iwatesan, Japan | Taal, Philippines Ongoing Activity: Adams, United States | Aira, Japan | Bezymianny, Russia | Dukono, Indonesia | Ebeko, Russia | Fuego, Guatemala | Great Sitkin, United States | Ibu, Indonesia | Kanlaon, Philippines | Karymsky, Russia | Lewotobi, Indonesia | Manam, Papua New Guinea | Merapi, Indonesia | Rincon de la Vieja, Costa Rica | Ruapehu, New Zealand | Santa Maria, Guatemala | Semeru, Indonesia | Sheveluch, Russia | Stromboli, Italy | 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 Iwatesan | Japan | 39.853°N, 141.001°E | Summit elev. 2038 m Japan Meteorological Agency (JMA) reported increased unrest at Iwatesan. Data from instrumentation detecting deformation indicated inflation centered in deeper parts of the volcano beginning in February. The frequency of volcanic earthquakes had been somewhat high since April 2020, although the number of small volcanic earthquakes located near Kurokurayama began increasing in May and further increased in late July. Results in INSAR imagery collected on 26 September revealed very shallow inflation near Ojigokudani (erosional caldera to the W). At 1500 on 2 October the Alert level was raised to 2 (the second lowest level on a 1-5 scale) prompting access restrictions around the crater; the public was warned that an eruption could affect an area within a 2 km radius of the crater. Geologic Summary. Viewed from the east, Iwatesan volcano has a symmetrical profile that invites comparison with Fuji, but on the west an older cone is visible containing an oval-shaped, 1.8 x 3 km caldera. After the growth of Nishi-Iwate volcano beginning about 700,000 years ago, activity migrated eastward to form Higashi-Iwate volcano. Iwate has collapsed seven times during the past 230,000 years, most recently between 739 and 1615 CE. The dominantly basaltic summit cone of Higashi-Iwate volcano, Yakushidake, is truncated by a 500-m-wide crater. It rises well above and buries the eastern rim of the caldera, which is breached by a narrow gorge on the NW. A central cone containing a 500-m-wide crater partially filled by a lake is located in the center of the oval-shaped caldera. A young lava flow from Yakushidake descended into the caldera, and a fresh-looking lava flow from the 1732 eruption traveled down the NE flank. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hPl81kHwQ$> Taal | Philippines | 14.0106°N, 120.9975°E | Summit elev. 311 m Philippine Institute of Volcanology and Seismology (PHIVOLCS) issued advisories for Taal reporting that a total of 30 phreatic events were recorded almost daily during 22 September-5 October. Five phreatic events during the morning of 5 October were recorded by the seismic network. A minor phreatomagmatic eruption began at 1132 and lasted four minutes based on visual observations and seismic and infrasound data. The eruption ejected a short, black plume followed by a steam-rich plume that rose 2 km above the crater rim and drifted SW. Trace ashfall was reported in Agoncillo, Batangas, W of Taal Lake. Sulfur dioxide emissions averaged 2,068 tonnes per day (t/d) during 5-6 October and 1,267 t/d on 7 October, remaining at elevated levels. One small phreatic event was recorded during 6-7 October, and two phreatic events lasting 1-4 minutes long were recorded during 7-8 October. Hot fluids upwelling in the lake were observed during 5-8 October along with emissions that rose 900 m above the crater rim and drifted SW. The Alert Level remained at 1 (on a scale of 0-5), and PHIVOLCS reminded the public that the entire Taal Volcano Island was a Permanent Danger Zone (PDZ) and recommended that the Main Crater and areas along the Daang Kastila fissure should remain prohibited. Geologic Summary. Taal is one of the most active volcanoes in the Philippines and has produced some powerful eruptions. The 15 x 20 km Talisay (Taal) caldera is largely filled by Lake Taal, whose 267 km2 surface lies only 3 m above sea level. The maximum depth of the lake is 160 m, with several submerged eruptive centers. The 5-km-wide Volcano Island in north-central Lake Taal is the location of all observed eruptions. The island is composed of coalescing small stratovolcanoes, tuff rings, and scoria cones. Powerful pyroclastic flows and surges have caused many fatalities. 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!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hNFxOyh0Q$> Ongoing Activity Adams | United States | 46.206°N, 121.49°W | Summit elev. 3742 m The Cascades Volcano Observatory (CVO) issued an information statement about seismicity at Adams. In the month of September six locatable earthquakes with magnitudes of 0.9-2 were recorded by one seismic station located 11 km SW of the summit and others located much farther away. Typically, at Adams, one earthquake is recorded every 2-3 years. CVO noted that there was no indication that the earthquake activity was a cause for concern; the Volcano Alert Level remained at Normal (the lowest level on a four-level scale) and the Aviation Color Code remained at Green (the lowest color on a four-color scale). CVO together with the Pacific Northwest Seismic Network (PNSN) plan to install temporary seismic stations in the Adams area, which will allow detection of smaller earthquakes and better estimates of size, location, and depth, information necessary to assess the significance of the activity. Geologic Summary. The andesitic-dacitic Mount Adams stratovolcano is second in volume only to Mount Shasta in the Cascade Range. The volcanic complex is elongated along a NNW-SSE line, and includes more than 60 flank vents over 200 km2. Volcanism began about 940 ka, with three main cone-building stages occurring at about 500, 450, and 30 ka. It was active throughout the Holocene, producing two dozen minor explosive eruptions from summit and flank vents. Six Holocene lava flows are located on the flanks between 2,100 and 2,600 m elevation. The most voluminous Holocene lava flows, some of which traveled 10 km or more, were emplaced between about 7,000 and 4,000 years ago. The latest eruption about 1,000 years ago produced a minor tephra layer and possibly a small lava flow down the E flank. Source: US Geological Survey Cascades Volcano Observatory (CVO) https://volcanoes.usgs.gov/observatories/cvo/ <https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/cvo/__;!!IKRxdwAv5BmarQ!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hPmwlGDMg$> Aira | Japan | 31.5772°N, 130.6589°E | Summit elev. 1117 m Japan Meteorological Agency (JMA) reported ongoing eruptive activity at Minamidake Crater (Aira Calderaâ??s Sakurajima volcano) during 30 September-7 October. Crater incandescence was visible in webcam images. On 30 September sulfur dioxide emissions were very high, averaging 3,400 tons per day. Very small eruptive events were occasionally recorded during 30 September-4 October. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to stay 1 km away from both 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!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hPl81kHwQ$> Bezymianny | Russia | 55.972°N, 160.595°E | Summit elev. 2882 m The Kamchatka Volcanic Eruption Response Team (KVERT) reported that a thermal anomaly over Bezymianny was identified in satellite images during 27-28 and 30 September. The volcano was obscured by weather clouds on the other days of the week. On 3 October a plume of resuspended ash lifted from the S flank by strong winds was visible in satellite images drifting 450 km ESE. The resuspended ash prompted KVERT to briefly raise the Aviation Color Code from Yellow to Orange (the second highest level on a four-color scale) at 2136; the Aviation Color Code was lowered back to Yellow at 0241 on 4 October. The plume was 1,400 km SE of the volcano on 4 October. Geologic Summary. The modern Bezymianny, much smaller than its massive neighbors Kamen and Kliuchevskoi on the Kamchatka Peninsula, was formed about 4,700 years ago over a late-Pleistocene lava-dome complex and an edifice built about 11,000-7,000 years ago. Three periods of intensified activity have occurred during the past 3,000 years. The latest period, which was preceded by a 1,000-year quiescence, began with the dramatic 1955-56 eruption. This eruption, similar to that of St. Helens in 1980, produced a large open crater that was formed by collapse of the summit and an associated lateral blast. Subsequent episodic but ongoing lava-dome growth, accompanied by intermittent explosive activity and pyroclastic flows, has largely filled the 1956 crater. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hPhvmzYNQ$> Dukono | Indonesia | 1.6992°N, 127.8783°E | Summit elev. 1273 m Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that the eruption at Dukono was ongoing during 2-8 October. Daily dense gray-and-white ash plumes rose 100-800 m above the summit and drifted W and SW. The Alert Level remained at Level 2 (on a scale of 1-4), and the public was warned to remain outside of the 3-km exclusion zone. Geologic Summary. Reports from this remote volcano in northernmost Halmahera are rare, but Dukono has been one of Indonesia's most active volcanoes. More-or-less 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 N-flank Gunung Mamuya cone. This complex volcano presents a broad, low profile with multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of the summit crater complex, contains a 700 x 570 m crater that has also been active during 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!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hOYeF75BA$> Ebeko | Russia | 50.686°N, 156.014°E | Summit elev. 1103 m The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that moderate activity was ongoing at Ebeko during 26 September-4 October. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E), the volcano was quiet or obscured by weather clouds. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates are UTC; specific events are in local time where noted. Geologic Summary. The flat-topped summit of the central cone of Ebeko volcano, one of the most active in the Kuril Islands, occupies the northern end of Paramushir Island. Three summit craters located along a SSW-NNE line form Ebeko volcano proper, at the northern end of a complex of five volcanic cones. Blocky lava flows extend west from Ebeko and SE from the neighboring Nezametnyi cone. The eastern part of the southern crater contains strong solfataras and a large boiling spring. The central crater is filled by a lake about 20 m deep whose shores are lined with steaming solfataras; the northern crater lies across a narrow, low barrier from the central crater and contains a small, cold crescentic lake. Historical activity, recorded since the late-18th century, has been restricted to small-to-moderate explosive eruptions from the summit craters. Intense fumarolic activity occurs in the summit craters, on the outer flanks of the cone, and in lateral explosion craters. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hPhvmzYNQ$> Fuego | Guatemala | 14.473°N, 90.88°W | Summit elev. 3763 m Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH) reported that eruptive activity continued at Fuego during 1-8 October. Daily explosions were recorded by the seismic network, averaging 3-12 per hour when reported. The explosions generated gas-and-ash plumes that rose as high as 1.1 km above the crater rim and drifted as far as 30 km in multiple directions. Weak rumbling sounds and shock waves from explosions were occasionally reported. On most days the explosions ejected incandescent material up to 350 m above the summit and onto the upper flanks. The explosions often produced avalanches of material that descended the flanks, sometimes reaching vegetated areas. Ashfall was reported in areas downwind including Panimaché I and II (8 km SW), Yepocápa (8 km NW), Sangre de Cristo (10 km SW), and Finca Palo Verde during 4-5 October and La Rochela (8 km SSW), Finca Ceilán (9 km S), La Reunión (7 km SE), El Rodeo (10 km SSE), El Zapote (10 km SSE), El Porvenir (8 km ENE), and Alotenángo (8 km ENE) during 6-7 October. Ashfall was forecast for areas downwind on the other days. Geologic Summary. Volcán Fuego, one of Central America's most active volcanoes, is also one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between Fuego and Acatenango to the north. Construction of Meseta dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta may have produced the massive Escuintla debris-avalanche deposit, which extends about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at the mostly andesitic Acatenango. Eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. Frequent vigorous historical eruptions have been recorded since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows. 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!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hPCjVaBaw$> Great Sitkin | United States | 52.076°N, 176.13°W | Summit elev. 1740 m Alaska Volcano Observatory (AVO) reported that slow lava effusion continued to feed a thick lava flow in Great Sitkinâ??s summit crater during 2-8 October. The lava flow had filled most of the summit crater. The local seismic network continued to detect small earthquakes associated with the ongoing eruption. Weather clouds often obscured webcam and satellite views of the summit. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale). Geologic Summary. The Great Sitkin volcano forms much of the northern side of Great Sitkin Island. A younger volcano capped by a small, 0.8 x 1.2 km ice-filled summit caldera was constructed within a large late-Pleistocene or early Holocene scarp formed by massive edifice failure that truncated an older edifice and produced a submarine debris avalanche. Deposits from this and an even older debris avalanche from a source to the south cover a broad area of the ocean floor north of the volcano. The summit lies along the eastern rim of the younger collapse scarp. Deposits from an earlier caldera-forming eruption of unknown age cover the flanks of the island to a depth up to 6 m. The small younger caldera was partially filled by lava domes emplaced in 1945 and 1974, and five small older flank lava domes, two of which lie on the coastline, were constructed along northwest- and NNW-trending lines. Hot springs, mud pots, and fumaroles occur near the head of Big Fox Creek, south of the volcano. Eruptions have been recorded since the late-19th century. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://avo.alaska.edu/ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hO2n4TpbQ$> Ibu | Indonesia | 1.488°N, 127.63°E | Summit elev. 1325 m Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that activity at Ibu continued during 2-8 October. Gray or white-and-gray ash plumes that were sometimes dense rose 0.5-1 km above the summit and drifted NE, NW, W, and SW during 2-5 October. Webcam images posted with the reports during 3-4 October showed incandescence visible above the crater rim. One eruptive event was recorded on 7 October, although emissions were not observed. The Alert Level remained at 3 (the second highest level on a four-level scale) and the public was advised to stay 4 km away from the active crater and 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!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hOYeF75BA$> Kanlaon | Philippines | 10.4096°N, 123.13°E | Summit elev. 2422 m Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported continuing unrest at Kanlaon during 2-8 October, characterized by increased seismicity and sulfur dioxide emissions. The seismic network recorded 5-15 daily volcanic earthquakes. Daily gas-and-steam emissions that were often voluminous rose 100-650 m above the summit and drifted NE, W, SW, and S. Sulfur dioxide emissions were recorded daily and continued to be high, averaging 2,606-9,042 tonnes/day. The Alert Level remained at 2 (on a scale of 0-5) and PHIVOLCS reminded the public to remain outside of the 4-km-radius Permanent Danger Zone and warned pilots not to fly close to the volcano. Geologic Summary. Kanlaon volcano (also spelled Canlaon) forms the highest point on the Philippine island of Negros. The massive andesitic stratovolcano is covered with fissure-controlled pyroclastic cones and craters, many of which are filled by lakes. The largest debris avalanche known in the Philippines traveled 33 km SW from Kanlaon. The summit contains a 2-km-wide, elongated northern caldera with a crater lake and a smaller but higher active vent, Lugud crater, to the south. Eruptions recorded since 1866 have typically consisted of phreatic explosions of small-to-moderate size that produce minor local ashfall. Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS) http://www.phivolcs.dost.gov.ph/ <https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hNFxOyh0Q$> Karymsky | Russia | 54.049°N, 159.443°E | Summit elev. 1513 m Kamchatkan Volcanic Eruption Response Team (KVERT) reported moderate levels of activity at Karymsky during 26 September-4 October. A minor thermal anomaly over the volcano was identified in satellite images on 27 and 30 September; weather clouds obscured views on the other days. A plume of resuspended ash drifted 300 km SE on 30 September and 3 October. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted. 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://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hPhvmzYNQ$> Lewotobi | Indonesia | 8.542°S, 122.775°E | Summit elev. 1703 m Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Lewotobiâ??s Laki-laki volcano continued during 2-8 October from a vent on the upper NW flank. Daily gray or white-and-gray ash plumes that were sometimes dense rose as high as 1.2 km above the summit and drifted SW, W, and NW. Incandescence at the vent was visible in a webcam image on 3 October. The Alert Level remained at 3 (the second highest level on a scale of 1-4) and the public was warned to stay outside of the exclusion zone, defined as a 3 km radius around both Laki-laki and Perempuan craters, 4 km to the NNW and SSE of Laki-laki. Geologic Summary. The Lewotobi edifice in eastern Flores Island is composed of the two adjacent Lewotobi Laki-laki and Lewotobi Perempuan stratovolcanoes (the "husband and wife"). Their summits are less than 2 km apart along a NW-SE line. The conical Laki-laki to the NW has been frequently active during the 19th and 20th centuries, while the taller and broader Perempuan has had observed eruptions in 1921 and 1935. Small lava domes have grown during the 20th century in both of the summit craters, which are open to the north. A prominent cone, Iliwokar, occurs on the E flank of Perampuan. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hOYeF75BA$> Manam | Papua New Guinea | 4.08°S, 145.037°E | Summit elev. 1807 m The Darwin VAAC reported that ash plumes from Manam were identified in satellite and webcam images, and reported by the Rabaul Volcano Observatory, rising to 2.7 km (9,000 ft) a.s.l., or about 1 km above the summit, and drifting NW at 1000 on 3 October. The ash emissions were continuous during 3-5 October, though weather clouds sometimes obscured views. The ash had dissipated by 2140 on 5 October. At 1250 on 7 October a continuous ash plume was identified in satellite images rising to 2.4 km (8,000 ft) a.s.l. and drifting NW. Geologic Summary. The 10-km-wide island of Manam, lying 13 km off the northern coast of mainland Papua New Guinea, is one of the country's most active volcanoes. Four large radial valleys extend from the unvegetated summit of the conical basaltic-andesitic stratovolcano to its lower flanks. These valleys channel lava flows and pyroclastic avalanches that have sometimes reached the coast. Five small satellitic centers are located near the island's shoreline on the northern, southern, and western sides. Two summit craters are present; both are active, although most observed eruptions have originated from the southern crater, concentrating eruptive products during much of the past century into the SE valley. Frequent eruptions, typically of mild-to-moderate scale, have been recorded since 1616. Occasional larger eruptions have produced pyroclastic flows and lava flows that reached flat-lying coastal areas and entered the sea, sometimes impacting populated areas. Source: Darwin Volcanic Ash Advisory Centre (VAAC) http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml <https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hMhDsX4Xw$> Merapi | Indonesia | 7.54°S, 110.446°E | Summit elev. 2910 m Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG) reported that the eruption at Merapi (on Java) continued during 27 September-3 October. Seismicity was more intense compared to the previous week. The SW lava dome produced 256 lava avalanches that traveled as far as 1.8 km down the Bebeng drainage on the SW flank. Morphological changes to the SW lava dome resulting from continuing effusion and collapses of material. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-7 km away from the summit, based on location. Geologic Summary. Merapi, one of Indonesia's most active volcanoes, lies in one of the world's most densely populated areas and dominates the landscape immediately north of the major city of Yogyakarta. It is the youngest and southernmost of a volcanic chain extending NNW to Ungaran volcano. Growth of Old Merapi during the Pleistocene ended with major edifice collapse perhaps about 2,000 years ago, leaving a large arcuate scarp cutting the eroded older Batulawang volcano. Subsequent growth of the steep-sided Young Merapi edifice, its upper part unvegetated due to frequent activity, began SW of the earlier collapse scarp. Pyroclastic flows and lahars accompanying growth and collapse of the steep-sided active summit lava dome have devastated cultivated lands on the western-to-southern flanks and caused many fatalities. Source: Balai Penyelidikan dan Pengembangan Teknologi Kegunungapian (BPPTK) http://www.merapi.bgl.esdm.go.id/index.php <https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/index.php__;!!IKRxdwAv5BmarQ!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hOCVmi0Hw$> Rincon de la Vieja | Costa Rica | 10.83°N, 85.324°W | Summit elev. 1916 m Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA) reported that small phreatic eruptions at Rincón de la Vieja were recorded at 0822 on 2 October, at 1240 and 2248 on 3 October, at 0748 on 4 October, and at 1732 on 6 October. None of the events produced emissions with ash. Geologic Summary. Rincón de la Vieja, the largest volcano in NW Costa Rica, is a remote volcanic complex in the Guanacaste Range. The volcano consists of an elongated, arcuate NW-SE-trending ridge constructed within the 15-km-wide early Pleistocene GuachipelÃn caldera, whose rim is exposed on the south side. Sometimes known as the "Colossus of Guanacaste," it has an estimated volume of 130 km3 and contains at least nine major eruptive centers. Activity has migrated to the SE, where the youngest-looking craters are located. The twin cone of Santa MarÃa volcano, the highest peak of the complex, is located at the eastern end of a smaller, 5-km-wide caldera and has a 500-m-wide crater. A Plinian eruption producing the 0.25 km3 RÃo Blanca tephra about 3,500 years ago was the last major magmatic eruption. All subsequent eruptions, including numerous historical eruptions possibly dating back to the 16th century, have been from the prominent active crater containing a 500-m-wide acid lake located ENE of Von Seebach crater. 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!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hOgSM8AtA$> Ruapehu | New Zealand | 39.28°S, 175.57°E | Summit elev. 2797 m GeoNet reported that minor unrest continued at Ruapehu and the crater lake remained cool. The temperature of the crater lake water decreased from 31 to 11 degrees Celsius during March-August and remained cool through 8 October, decreasing further to 8 degrees, the lowest temperature recorded since 1970. Sulfur dioxide emissions were at low-to-moderate levels. The reduced temperature and sulfur dioxide emissions suggested partial sealing of the vent; areas of upwelling on the lakeâ??s surface and sulfur slicks were visible on 30 September. Volcanic tremor levels remained low during 2024. The Volcanic Alert Level remained at 1 (on a scale from 0-5) and the Aviation Color Code remained at Green (the lowest level on a four-color scale). Geologic Summary. Ruapehu, one of New Zealand's most active volcanoes, is a complex stratovolcano constructed during at least four cone-building episodes dating back to about 200,000 years ago. The dominantly andesitic 110 km3 volcanic massif is elongated in a NNE-SSW direction and surrounded by another 100 km3 ring plain of volcaniclastic debris, including the NW-flank Murimoto debris-avalanche deposit. A series of subplinian eruptions took place between about 22,600 and 10,000 years ago, but pyroclastic flows have been infrequent. The broad summait area and flank contain at least six vents active during the Holocene. Frequent mild-to-moderate explosive eruptions have been recorded from the Te Wai a-Moe (Crater Lake) vent, and tephra characteristics suggest that the crater lake may have formed as recently as 3,000 years ago. Lahars resulting from phreatic eruptions at the summit crater lake are a hazard to a ski area on the upper flanks and lower river valleys. Source: GeoNet http://www.geonet.org.nz/ <https://urldefense.com/v3/__http://www.geonet.org.nz/__;!!IKRxdwAv5BmarQ!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hODTE1t3w$> Santa Maria | Guatemala | 14.757°N, 91.552°W | Summit elev. 3745 m Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH) reported ongoing eruptive activity at Santa Mariaâ??s Santiaguito cone during 1-8 October with continuing lava extrusion at Caliente dome. Daily explosions (a few per hour) generated gas-and-ash plumes that rose as high as 900 m above the summit and drifted mainly SW, W, N, and NE. Effusion of blocky lava and collapses of material produced block avalanches and occasional short pyroclastic flows that descended the flanks. Incandescence was sometimes visible during dark hours from avalanches of material at the dome as well as explosions. Ashfall was reported in Santa MarÃa de Jesús (5 km SE), Calaguaché (9 km S), Belén (10 km S), and other areas downwind during 6-7 October. 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!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hPCjVaBaw$> Semeru | Indonesia | 8.108°S, 112.922°E | Summit elev. 3657 m Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity continued at Semeru during 25 September-1 October with multiple daily eruptive events recorded by the seismic network. Almost daily white-and-gray ash plumes that were sometimes dense rose 0.1-1 km m above the summit and drifted W, SW, and S; eruptive events were recorded during 7-8 October, but no emissions were observed. The Alert Level remained at 2 (the second lowest level on a scale of 1-4). The public was warned to stay at least 5 km away from the summit in all directions, 13 km from the summit to the SE, 500 m from the banks of the Kobokan drainage as far as 17 km from the summit, and to avoid other drainages including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards. Geologic Summary. Semeru, the highest volcano on Java, and one of its most active, lies at the southern end of a volcanic massif extending north to the Tengger caldera. The steep-sided volcano, also referred to as Mahameru (Great Mountain), rises above coastal plains to the south. Gunung Semeru was constructed south of the overlapping Ajek-ajek and Jambangan calderas. A line of lake-filled maars was constructed along a N-S trend cutting through the summit, and cinder cones and lava domes occupy the eastern and NE flanks. Summit topography is complicated by the shifting of craters from NW to SE. Frequent 19th and 20th century eruptions were dominated by small-to-moderate explosions from the summit crater, with occasional lava flows and larger explosive eruptions accompanied by pyroclastic flows that have reached the lower flanks of the volcano. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hOYeF75BA$> Sheveluch | Russia | 56.653°N, 161.36°E | Summit elev. 3283 m Kamchatkan Volcanic Eruption Response Team (KVERT) reported that during 26 September-4 October lava extrusion may have continued at Sheveluchâ??s â??300 years of RASâ?? dome on the SW flank of Old Sheveluch and at the dome at Young Sheveluch. Thermal anomalies over the domes were identified in satellite images during 27-30 September and 2 October. Plumes of resuspended ash drifted 1,100 km SE on 30 September and 3 October. Weather conditions prevented views on the other days of the week. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; 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://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hPhvmzYNQ$> Stromboli | Italy | 38.789°N, 15.213°E | Summit elev. 924 m Sezione di Catania - Osservatorio Etneo (INGV) reported that eruptive activity continued at Stromboli during 30 September-6 October with notable events on 1 and 6 October. Webcam images showed Strombolian activity at two vents in Area N within the upper part of the Sciara del Fuoco and from at least two vents in Area C-S (South-Central Crater) on the crater terrace. The vents in Area N continued to produce explosions at a rate of 5-8 events per hour, ejecting lapilli and bombs less than 80 m above the vents. Spattering continued and was sometimes intense, particularly on 30 September and 1 and 6 October. Explosions at the vent in Area C-S mainly occurred at a rate of 1-3 events per hour and ejected tephra over 250 m above the vent. Intense spattering in Area N on 1 October was followed by the formation of a lava flow at around 1500 that descended the Sciara del Fuoco and accumulated at the coastline. The lava flow was cooling and no longer active by 2100. Explosions at both crater areas occurred during a three-minute period on 6 October. At 0217 an energetic explosion at Area N lasted 50 seconds and ejected lapilli, bombs, and lava fragments that fell in a rose pattern, predominantly along the Sciara del Fuoco. The explosion was followed by at least three more notable explosions at Area C-S and additional smaller ones; the explosions ejected material that mostly rolled down the Sciara del Fuoco and did not reach the coastline. Over the next two hours spattering at Area N fed a lava flow that advanced down the Sciara del Fuoco. The Alert Level remained at Yellow (the second lowest level on a four-level scale). Geologic Summary. Spectacular incandescent nighttime explosions at Stromboli have long attracted visitors to the "Lighthouse of the Mediterranean" in the NE Aeolian Islands. This volcano has lent its name to the frequent mild explosive activity that has characterized its eruptions throughout much of historical time. The small island is the emergent summit of a volcano that grew in two main eruptive cycles, the last of which formed the western portion of the island. The Neostromboli eruptive period took place between about 13,000 and 5,000 years ago. The active summit vents are located at the head of the Sciara del Fuoco, a prominent scarp that formed about 5,000 years ago due to a series of slope failures which extends to below sea level. The modern volcano has been constructed within this scarp, which funnels pyroclastic ejecta and lava flows to the NW. Essentially continuous mild Strombolian explosions, sometimes accompanied by lava flows, have been recorded for more than a millennium. Sources: Sezione di Catania - Osservatorio Etneo (INGV) http://www.ct.ingv.it/ <https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hNGId9ZFg$> ; Dipartimento della Protezione Civile https://www.protezionecivile.gov.it/it/ <https://urldefense.com/v3/__https://www.protezionecivile.gov.it/it/__;!!IKRxdwAv5BmarQ!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hNGA4rTCA$> Suwanosejima | Japan | 29.638°N, 129.714°E | Summit elev. 796 m Japan Meteorological Agency (JMA) reported that eruptive activity at Suwanosejima's Ontake Crater continued during 30 September-7 October. Crater incandescence was observed nightly in webcam images. Three eruptive events on 30 September produced ash-and-gas plumes that rose 1-1.3 km above the crater rim and drifted W. At 0031 on 1 October continuous ash-and-gas plumes rose 0.6-1.1 km above the crater rim and drifted W, N, and NE; ash was no longer detected by 1710. An eruptive event on 4 October generated an ash-and-gas plume that rose 1.5 km above the crater rim. Continuous ash-and-gas emissions that began at 1256 on 4 October likely ceased around 0620 on 5 October, although weather conditions obscured views; ash-and-gas plumes rose as high as 2 km above the crater rim and drifted NE, N, and NW. On 7 October ash-and-gas plumes rose 1.1-1.5 km above the crater rim and drifted E. The Alert Level remained at 2 (on a 5-level scale) and the public was warned to stay at least 1.5 km away from 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!ZMyKBpJ8hswRB8rJa2lPStHCAnKVc8ZiDX8AlJUIdfE_BVfRAXlj3rnVbcju8gExfv-CJgMyt-VK6xOR-hPl81kHwQ$> 8-8-8-8-8-8-8-8-8-8-8-8-8 ============================================================== Volcano Listserv is a collaborative venture among Arizona State University (ASU), Portland State University (PSU), the Global Volcanism Program (GVP) of the Smithsonian Institution's National Museum of Natural History, and the International Association for Volcanology and Chemistry of the Earth's Interior (IAVCEI). 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