3-3-3-3-3-3-3-3-3-3-3-3-3 From: "Kuhn, Sally" <KUHNS@xxxxxx> Smithsonian / USGS Weekly Volcanic Activity Report 18-24 September 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!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntXm7ReMfA$> New Activity/Unrest: Bagana, Papua New Guinea | Kanlaon, Philippines | Kilauea, United States | Sumisujima, Japan | Whakaari/White Island, New Zealand Ongoing Activity: Aira, Japan | Ebeko, Russia | Erta Ale, Ethiopia | Etna, Italy | Fuego, Guatemala | Great Sitkin, United States | Ibu, Indonesia | Karymsky, Russia | Kelimutu, Indonesia | Lewotobi, Indonesia | Merapi, Indonesia | Rincon de la Vieja, Costa Rica | Sangay, Ecuador | 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 Bagana | Papua New Guinea | 6.137°S, 155.196°E | Summit elev. 1855 m The Darwin VAAC reported that continuous ash plumes from Bagana were identified in satellite images rising to 3.7 km (12,000 ft) a.s.l. and drifting W and SW during 17-20 September. Weather clouds sometimes obscured views. Geologic Summary. Bagana volcano, in a remote portion of central Bougainville Island, is frequently active. This massive symmetrical cone was largely constructed by an accumulation of viscous andesitic lava flows. The entire edifice could have been constructed in about 300 years at its present rate of lava production. Eruptive activity is characterized by non-explosive effusion of viscous lava that maintains a small lava dome in the summit crater, although occasional explosive activity produces pyroclastic flows. Lava flows with tongue-shaped lobes up to 50 m thick and prominent levees descend the flanks on all sides. 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!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntVA3QeBcg$> 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 17-24 September, characterized by increased seismicity and sulfur dioxide emissions. The seismic network recorded five volcanic earthquakes during 17-18 September and 15-55 daily volcanic earthquakes during the rest of the week. Weather clouds obscured views of the summit during 17-19 September. Voluminous gas-and-steam emissions rose 300-800 m above the summit and drifted in multiple directions during 20-23 September. Sulfur dioxide emissions were recorded daily and continued to be high, averaging 5,362-10,449 tonnes/day. According to a Disaster Response Operations Monitoring and Information Center (DROMIC) report there were a total of 3,905 people in evacuation centers as of 22 September. 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. Sources: Philippine Institute of Volcanology and Seismology (PHIVOLCS) http://www.phivolcs.dost.gov.ph/ <https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntXhl9a42A$> ; Disaster Response Operations Monitoring and Information Center (DROMIC) https://dromic.dswd.gov.ph/ <https://urldefense.com/v3/__https://dromic.dswd.gov.ph/__;!!IKRxdwAv5BmarQ!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntXbCl1dMw$> Kilauea | United States | 19.421°N, 155.287°W | Summit elev. 1222 m Hawaiian Volcano Observatory (HVO) reported that the eruption at Kilauea which began on 15 September from fissures to the W of Napau Crater and on the crater floor continued during 17-19 September, and then paused on 20 September. The eruption area is located in a remote section of the middle East Rift Zone. The opening of new fissures on the Napau Crater floor during 0400-0500 on 17 September was detected using infrasound signals, a thermal anomaly identified in a GOES satellite image, and webcam views. During an overflight later that morning, scientists observed lava fountaining 10 m high along the fissures and lava flows advancing on the crater floor. The activity was vigorous but had started to wane by the afternoon. During an overflight on the morning of 18 September, volcanologists observed only minor activity on the crater floor. Only one vent was active and produced low lava fountains in a tiny pond, and there was some residual movement of lava along a margin of the flow field. A small new flow at the W end of the fissure system was inactive. Steam-and-gas continued to be emitted from the fissures to the W of the crater that had opened on 15 September. New fissures opened W of the crater at around 1515 on 18 September. Flows from lava fountains along the fissure rapidly advanced E and cascaded down the NW wall of Napau Crater onto the crater floor. Sulfur dioxide emissions averaged 10,000 tonnes per day, associated with the opening of the new vents. The lava falls continued overnight during 18-19 September and by around 1000 on 19 September about one-third of the crater floor, or approximately 250,000 square meters, was covered by lava. The amount of coverage suggested that the lava effusion rate was 5-15 cubic meters per second during the most active phase. Activity greatly diminished overnight; the lava channels and falls began to crust over by 2000 and during 2100-2200 they had completely crusted over. Strong incandescence from the vent began to decrease around 0230 on 20 September. Field crews observed minor spattering and small fountains at one end of the vent at around 0830, but by 1000 no activity was seen, and the eruption had paused. In total lava flows covered about 63 hectares (630,000 square meters) of Napau Crater and areas to the W. At 0812 on 23 September the Volcano Alert Level was lowered to Advisory (the second level on a four-level scale) and the Aviation Color Code was lowered to Yellow (the second color on a four-color scale). HVO noted that observations and instrumental data since the pause in the eruption indicated that the potential for renewed eruptive activity had declined. Seismicity in the area was extremely low and no tremor was being recorded. Deformation data showed that magma movement to the middle East Rift Zone has slowed dramatically or stopped altogether. Volcanic gas emissions decreased to near background levels. 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!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntXDw0y0Hg$> Sumisujima | Japan | 31.44°N, 140.051°E | Summit elev. 136 m According to the Japan Meteorological Agency (JMA) discolored water around Sumisujima was observed on 18 September during an overflight conducted by the Japan Coast Guard. An area of pale-blue to white discolored water extended about 1.8 km NW of the N coast of the island. A very small amount of grayish-white material was floating in the same area as the discolored water and along the W coast. At 1100 on 19 September JMA issued an â??eruption warningâ?? noting that an eruption could affect the surround waters of the island. Geologic Summary. Sumisujima (also known as Smith Rocks) is a steep-sided basaltic pinnacle that forms part of the outer southern flank of a 8-9 km wide submarine caldera that truncates a 20-km-wide seamount. The caldera was formed between about 60,000 and 30,000 years ago. The Shirane dacitic central cone, 3 km wide and 800 m high, rises to within 8 m of the ocean surface in the eastern side of the caldera, whose 600-700 m walls and outer flanks expose basaltic, andesitic, and rhyolitic rocks. Two large submarine cones, Sumisu Knolls No. 1 and 2, lie west of the caldera. Submarine eruptions have been reported from a number of locations near Sumisujima, the last of which occurred in 1916. Water discoloration has frequently been observed since the 1970's. In October 1992 a 6-km-long zone of discolored water was seen extending from the shallow Shirane rock mass near the eastern rim of the caldera, which rises to within 7 m of the ocean surface and is the youngest feature of the volcanic complex. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntVsPeSExQ$> Whakaari/White Island | New Zealand | 37.52°S, 177.18°E | Summit elev. 294 m The Wellington VAAC reported that low-level steam-and-gas emissions from Whakaari/White Island were visible in webcam and satellite images during 18-19 September. The plumes rose 900 m (3,000 ft) a.s.l. and drifted NE; there was no evidence that the plumes contained ash. Views were sometimes obscured by weather clouds. 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: Wellington Volcanic Ash Advisory Center (VAAC) http://vaac.metservice.com/ <https://urldefense.com/v3/__http://vaac.metservice.com/__;!!IKRxdwAv5BmarQ!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntX1S3gNNA$> Ongoing Activity Aira | Japan | 31.5772°N, 130.6589°E | Summit elev. 1117 m Japan Meteorological Agency (JMA) reported ongoing eruptive activity at Minamidake Crater (Aira Calderaâ??s Sakurajima volcano) during 16-23 September. Crater incandescence was visible in webcam images during dark hours, and there were occasional very small eruptive events. An explosion at 1332 on 16 September generated an ash plume that rose 1.5 km above the crater rim and drifted NW. During a field visit on 18 September sulfur dioxide emissions were high, averaging 2,200 tons per day. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to stay 1 km away from both craters. Geologic Summary. The Aira caldera in the northern half of Kagoshima Bay contains the post-caldera Sakurajima volcano, one of Japan's most active. Eruption of the voluminous Ito pyroclastic flow accompanied formation of the 17 x 23 km caldera about 22,000 years ago. The smaller Wakamiko caldera was formed during the early Holocene in the NE corner of the caldera, along with several post-caldera cones. The construction of Sakurajima began about 13,000 years ago on the southern rim and built an island that was joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kitadake summit cone ended about 4,850 years ago, after which eruptions took place at Minamidake. Frequent eruptions since the 8th century have deposited ash on the city of Kagoshima, located across Kagoshima Bay only 8 km from the summit. The largest recorded eruption took place during 1471-76. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntVsPeSExQ$> Ebeko | Russia | 50.686°N, 156.014°E | Summit elev. 1103 m Kamchatkan Volcanic Eruption Response Team (KVERT) reported that moderate explosive activity was ongoing at Ebeko during 12-19 September. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E), explosions during 12, 14-17, and 19 September generated ash plumes that rose as high as 2.5 km (8,200 ft) a.s.l. and drifted SW, N, and NE. Satellite data indicated that either no activity was observed, or weather conditions prevented views. 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!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntVbNEo7vA$> Erta Ale | Ethiopia | 13.601°N, 40.666°E | Summit elev. 585 m A 14 September satellite image of Erta Ale showed an oval-shaped thermal anomaly just N of the N pit crater, possibly indicative of an active lava flow. The anomaly was absent in a 19 September image. Small thermal anomalies were visible over both the N and S pit craters in 14, 19, and 24 September images. Geologic Summary. The Erta Ale basaltic shield volcano in Ethiopia has a 50-km-wide edifice that rises more than 600 m from below sea level in the Danakil depression. The volcano includes a 0.7 x 1.6 km summit crater hosting steep-sided pit craters. Another larger 1.8 x 3.1 km wide depression elongated parallel to the trend of the Erta Ale range is located SE of the summit and is bounded by curvilinear fault scarps on the SE side. Basaltic lava flows from these fissures have poured into the caldera and locally overflowed its rim. The summit caldera usually also holds at least one long-term lava lake that has been active since at least 1967, and possibly since 1906. Recent fissure eruptions have occurred on the N flank. Source: Copernicus https://www.copernicus.eu/en <https://urldefense.com/v3/__https://www.copernicus.eu/en__;!!IKRxdwAv5BmarQ!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntVZZoxsRw$> Etna | Italy | 37.748°N, 14.999°E | Summit elev. 3357 m Sezione di Catania - Osservatorio Etneo (INGV) reported that mainly gas emissions rose from Etnaâ??s summit craters during 16-23 September. The activity was strongest at Bocca Nuova Crater where the gas emissions were dense and continuous, and occasionally contained ash. A series of explosions at NE Crater began at 2310 on 23 September and were visible in webcam images. Geologic Summary. Mount Etna, towering above Catania on the island of Sicily, has one of the world's longest documented records of volcanism, dating back to 1500 BCE. Historical lava flows of basaltic composition cover much of the surface of this massive volcano, whose edifice is the highest and most voluminous in Italy. The Mongibello stratovolcano, truncated by several small calderas, was constructed during the late Pleistocene and Holocene over an older shield volcano. The most prominent morphological feature of Etna is the Valle del Bove, a 5 x 10 km caldera open to the east. Two styles of eruptive activity typically occur, sometimes simultaneously. Persistent explosive eruptions, sometimes with minor lava emissions, take place from one or more summit craters. Flank vents, typically with higher effusion rates, are less frequently active and originate from fissures that open progressively downward from near the summit (usually accompanied by Strombolian eruptions at the upper end). Cinder cones are commonly constructed over the vents of lower-flank lava flows. Lava flows extend to the foot of the volcano on all sides and have reached the sea over a broad area on the SE flank. Source: Sezione di Catania - Osservatorio Etneo (INGV) http://www.ct.ingv.it/ <https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntVmrqNROA$> 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 17-24 September. Daily explosions were recorded by the seismic network, averaging 3-11 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 were reported on most days and shock waves were sometimes detected in local areas. The explosions ejected incandescent material generally up to 200 m above the summit on most days though material was ejected 300-400 m above the summit during 21-22 September. 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), El Porvenir (10 km S), Santa Sofia (12 km SW), Morelia (10 km SW), Los Yucales (12 km SW), and Yepocápa (8 km NW) during 17-18 September and in La Rochela (8 km SSW), Finca Ceilán (9 km S), El Zapote (10 km SSE), and El Rodeo during 21-22 September. 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!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntWRbsxQjw$> 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 17-24 September. The lava flow had filled most of the summit crater. The local seismic network continued to detect small earthquakes and other signals associated with the ongoing eruption. Elevated surface temperatures over the active flow were identified in satellite data during17-19 September. Weather clouds obscured views of the summit during the second part of the week. 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!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntWRWe54-Q$> Ibu | Indonesia | 1.488°N, 127.63°E | Summit elev. 1325 m Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that activity at Ibu continued during 18-24 September with multiple eruptive events recorded daily. Daily gray or white-and-gray ash plumes that were sometimes dense rose as high as 1.5 km above the summit and drifted in multiple directions. Webcam images posted with the reports showed incandescence visible above the crater rim. The Alert Level remained at 3 (the second highest level on a four-level scale) and the public was advised to stay 4 km away from the active crater and 5 km away from the N crater wall opening. Geologic Summary. The truncated summit of Gunung Ibu stratovolcano along the NW coast of Halmahera Island has large nested summit craters. The inner crater, 1 km wide and 400 m deep, has contained several small crater lakes. The 1.2-km-wide outer crater is breached on the N, creating a steep-walled valley. A large cone grew ENE of the summit, and a smaller one to the WSW has fed a lava flow down the W flank. A group of maars is located below the N and W flanks. The first observed and recorded eruption was a small explosion from the summit crater in 1911. Eruptive activity began again in December 1998, producing a lava dome that eventually covered much of the floor of the inner summit crater along with ongoing explosive ash emissions. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntX0ez8Sxg$> 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 12-19 September. A minor thermal anomaly over the volcano was identified in satellite images during 14-17 September; weather clouds obscured views on the other days. 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!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntVbNEo7vA$> Kelimutu | Indonesia | 8.77°S, 121.82°E | Summit elev. 1639 m Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that monitoring data and comparisons of recent field observations at Kelimutu indicated decreasing activity. Bubbling along the NE coast of the lake in Crater I (Tiwu Ata Polo) was observed on both 15 and 21 September. The temperature of the lake water was 22 and 24 degrees Celsius on 15 and 21 September, respectively. The lake water changed from dark green to bluish green. Conditions at Crater II (Tiwu Koofai Nuwamuri) were stable during 15-21 September, characterized by light blue crater water with small sulfur deposits floating in the middle of the lake and along the edges, diffuse white emissions rising 5 m above the lakeâ??s surface, and a water temperature of 30 degrees Celsius. The color of the lake water at Crater III (Tiwu Ata Bupu) remained dark green on 15 and 21 September, the lake water was calm, and the temperature was 21 and 22 degrees Celsius, respectively. Seismicity was lower in September compared to August. The Alert Level was lowered to 1 (on a scale of 1-4) at 1600 on 23 September and the public was advised to limit activities near the craters, not approach the lake water, and to not spend the night in the craters. Geologic Summary. Kelimutu is a small, but well-known, Indonesian compound volcano in central Flores Island with three summit crater lakes of varying colors. The western lake, Tiwi Ata Mbupu (Lake of Old People) is commonly blue. Tiwu Nua Muri Kooh Tai (Lake of Young Men and Maidens) and Tiwu Ata Polo (Bewitched, or Enchanted Lake), which share a common crater wall, are commonly colored green and red, respectively, although lake colors periodically vary. Active upwelling, probably fed by subaqueous fumaroles, occurs at the two eastern lakes. The scenic lakes are a popular tourist destination and have been the source of minor phreatic eruptions in historical time. The summit is elongated 2 km in a WNW-ESE direction; the older cones of Kelido (3 km N) and Kelibara (2 km S). 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!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntX0ez8Sxg$> 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 18-24 September 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. 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!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntX0ez8Sxg$> Merapi | Indonesia | 7.54°S, 110.446°E | Summit elev. 2910 m Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG) reported that the eruption at Merapi (on Java) continued during 13-19 September. Seismicity was slightly less intense compared to the previous week. The SW lava dome produced 426 lava avalanches that traveled as far as 1.9 km down the Bebeng drainage on the SW flank. Nine pyroclastic flows descended the Bebeng as far as 1.3 km. Morphological changes to the SW lava dome were due to continuing effusion and collapses of material. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-7 km away from the summit, based on location. Geologic Summary. Merapi, one of Indonesia's most active volcanoes, lies in one of the world's most densely populated areas and dominates the landscape immediately north of the major city of Yogyakarta. It is the youngest and southernmost of a volcanic chain extending NNW to Ungaran volcano. Growth of Old Merapi during the Pleistocene ended with major edifice collapse perhaps about 2,000 years ago, leaving a large arcuate scarp cutting the eroded older Batulawang volcano. Subsequent growth of the steep-sided Young Merapi edifice, its upper part unvegetated due to frequent activity, began SW of the earlier collapse scarp. Pyroclastic flows and lahars accompanying growth and collapse of the steep-sided active summit lava dome have devastated cultivated lands on the western-to-southern flanks and caused many fatalities. Source: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG) http://www.merapi.bgl.esdm.go.id/ <https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntWr4F9J5Q$> 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 a fumarolic plume from Rincón de la Vieja drifted NW on 18 September; weather clouds partly obscured views of the summit. A phreatic event was recorded at 2258 on 18 September and a very small phreatic event was recorded at 0328 on 20 September. 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!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntX_XUh9Sg$> Sangay | Ecuador | 2.005°S, 78.341°W | Summit elev. 5286 m Instituto GeofÃsico-Escuela Politécnica Nacional (IG-EPN) reported that high levels of eruptive activity continued at Sangay during 17-24 September and the seismic network recorded 244-473 daily explosions. Gas-and-ash plumes visible in webcam and/or satellite images on most days rose 0.6-1.2 km above the summit and drifted mainly W, WSW, and SW. Weather conditions often obscured views. Several daily episodes of crater incandescence were observed during dark hours and incandescent material descended the SE drainage as far as 1.8 km. Incandescent material was ejected 500 m above the summit during 22-23 September. SecretarÃa de Gestión de Riesgos (SGR) maintained the Alert Level at Yellow (the second highest level on a four-color scale). Geologic Summary. The isolated Sangay volcano, located east of the Andean crest, is the southernmost of Ecuador's volcanoes and its most active. The steep-sided, glacier-covered, dominantly andesitic volcano grew within the open calderas of two previous edifices which were destroyed by collapse to the east, producing large debris avalanches that reached the Amazonian lowlands. The modern edifice dates back to at least 14,000 years ago. It towers above the tropical jungle on the east side; on the other sides flat plains of ash have been eroded by heavy rains into steep-walled canyons up to 600 m deep. The earliest report of an eruption was in 1628. Almost continuous eruptions were reported from 1728 until 1916, and again from 1934 to the present. The almost constant activity has caused frequent changes to the morphology of the summit crater complex. Sources: Instituto GeofÃsico-Escuela Politécnica Nacional (IG-EPN) http://www.igepn.edu.ec/ <https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntXdybukMw$> ; SecretarÃa de Gestión de Riesgos (SGR) http://www.gestionderiesgos.gob.ec/ <https://urldefense.com/v3/__http://www.gestionderiesgos.gob.ec/__;!!IKRxdwAv5BmarQ!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntV3gKstJw$> 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 lava-dome complex during 17-24 September with lava extrusion, block collapses, and avalanches at the Caliente dome complex. Effusion of blocky lava produced block avalanches on the domeâ??s flanks and occasional short pyroclastic flows that descended the W, SW, and S flanks; the deposits created promontories of unstable material near the top of the 2022 lava flow located in the Zanjón Seco and San Isidro drainages. Incandescence was visible during dark hours from avalanches of material at the dome as well as explosions. Daily explosions (a few per hour) generated gas-and-ash plumes that rose as high as 800 m above the summit and sometimes drifted mainly W and SW. Ashfall was reported in San Marcos (8 km SW), Loma Linda Palajunoj (7 km SW), and surrounding areas during 17-18 September. 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!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntWRbsxQjw$> 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 18-24 September with multiple daily eruptive events recorded by the seismic network. White-and-gray ash plumes that were sometimes dense rose 150-500 m above the summit and drifted in multiple directions on most days; eruptive events were recorded on 23 September, 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!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntX0ez8Sxg$> Sheveluch | Russia | 56.653°N, 161.36°E | Summit elev. 3283 m Kamchatkan Volcanic Eruption Response Team (KVERT) reported that during 12-19 September lava extrusion likely continued at Sheveluchâ??s â??300 years of RASâ?? dome on the SW flank of Old Sheveluch and at the dome at Young Sheveluch. Thermal anomalies over the domes were identified in satellite images on 13 and 15 September; weather clouds obscured the volcano on the other days. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted. Geologic Summary. The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1,300 km3 andesitic volcano is one of Kamchatka's largest and most active volcanic structures, with at least 60 large eruptions during the Holocene. The summit of roughly 65,000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera breached to the south. Many lava domes occur on its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large open caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka. Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntVbNEo7vA$> 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 16-23 September. At 1403 on 17 September an eruptive event generated an ash plume that rose 1.3 km above the crater rim and drifted W. An explosion was recorded at 0233 on 20 September, though no details were reported about possible emissions. 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!d4-vYorSYy4CSmLXBJh_jrgNCf9zF74Pkk88z2UhEg200vr_0EwPyo2af7JHmux_-xCrcndkuTPGM6kuntVsPeSExQ$> 3-3-3-3-3-3-3-3-3-3-3-3-3 ============================================================== 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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