3-3-3-3-3-3-3-3-3-3-3-3-3 From: "Kuhn, Sally" <KUHNS@xxxxxx> Smithsonian / USGS Weekly Volcanic Activity Report 21-27 August 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!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10Qowy0Iqg$> New Activity/Unrest: Etna, Sicily (Italy) | Reykjanes, Reykjanes Peninsula | Sheveluch, Central Kamchatka (Russia) | Whakaari/White Island, North Island (New Zealand) Ongoing Activity: Aira, Kyushu (Japan) | Dukono, Halmahera | Ebeko, Paramushir Island (Russia) | Great Sitkin, Andreanof Islands (USA) | Ibu, Halmahera | Kanlaon, Philippines | Karymsky, Eastern Kamchatka (Russia) | Lewotobi, Flores Island | Marapi, Central Sumatra | Merapi, Central Java | Sabancaya, Peru | Semeru, Eastern Java | Stromboli, Aeolian Islands (Italy) | Suwanosejima, Ryukyu Islands (Japan) | Villarrica, Central Chile 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 Etna | Sicily (Italy) | 37.748°N, 14.999°E | Summit elev. 3357 m INGV reported that activity at Etnaâ??s summit craters continued during 19-25 August, though weather conditions often prevented visual observations during daylight hours. Continuous gas emissions were visible from the summit craters, especially at SE Crater (SEC). At 2154 on 23 August a thermal anomaly and a short-lived sequence of ash emissions from the E vent at SEC were visible in thermal 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!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10RvM789iQ$> Reykjanes | Reykjanes Peninsula | 63.817°N, 22.717°W | Summit elev. 140 m IMO reported that a new eruption began in a location between Stóra-Skógfell and Sundhnúkur, within the Reykanes volcanic system, after about a month of increasing seismicity and inflation and about a week of more intense seismicity and larger earthquakes. A 20 August report noted that seismicity had increased during the previous few days and that the estimated volume of magma that had accumulated beneath the surface was greater than it was prior to any previous eruption in the region. Two earthquakes with magnitudes greater than two were recorded during 19-20 August, making a total of six earthquakes with similar magnitudes recorded during the previous week. An earthquake swarm began at 2048 on 22 August and increased pressure was identified in borehole data; these data indicated that a dike had begun to propagate. At 2111 IMO raised the Aviation Color Code to Orange (the second highest level on a four-color scale). A fissure eruption began at 2126 on 22 August and within four minutes a gas plume had risen 1 km high and began drifting S. The Aviation Color Code was raised to Red at 2130, and a news source reported that possibly more than 1,000 people were evacuated from the Blue Lagoon Spa area. The fissure produced lava fountaining along its roughly SW-NE axis and propagated mostly NE, and by 2230 was 3.9 km in length. According to a news source observers noted that the lava fountains were likely taller than those from the previous eruptions in the area. Seismicity was concentrated near the N end of the fissure system. Lava flows spread E and W, towards GrindavÃkurvegur; flows did not head towards GrindavÃk. At 2145 the Aviation Color Code was lowered back to Orange because ash was not detected in the gas-rich plumes rising from the fissure. A M 4 earthquake recorded at 2237 was located about 3 km NE of Stóra-Skógsfell. As magma propagated from the reservoir to the surface a maximum of around 40 cm of land subsidence was recorded. As the fissure opened to the NE, activity along the S end of the fissure declined. The fissure consisted of at least two segments; the main segment that had opened first and a second shorter segment that was offset to the NW from the end of the original segment; the total length of the fissure was about 7 km long according to a news source. Seismicity rapidly decreased at around 0400 on 23 August. By 1000 the vigor of the eruption had decreased and was confined to the northernmost fissure segment. Explosive activity at around 1030 produced dark ash plumes that rose 1 km and local tephra fall based on webcam views. Lava was mostly moving to the NW, N of Stóra-Skógfell. By 1600 the rate of both the seismicity and ground deformation had decreased, and activity along the main fissure was low. Lava flows had caused extended wildfires in the area. Sulfur dioxide plumes from the eruption drifted more than 1,000 km SE towards Scotland. The lava extrusion rate on 24 August was estimated to be around 100 cubic meters per second, lower than the estimated rate of 1,500-2,000 cubic meters per second during the beginning phase of the eruption. During 25-26 August the activity was centered in one area at the N part of the fissure. Lava advanced N in two main channels though the advancement had slowed considerably. The lava extrusion rate had decreased to an estimated tens of cubic meters per second. Modeling suggested that 17-27 million cubic meters of magma had erupted, covering an area totaling 15.1 square kilometers. Geologic Summary. The Reykjanes volcanic system at the SW tip of the Reykjanes Peninsula, where the Mid-Atlantic Ridge rises above sea level, comprises a broad area of postglacial basaltic crater rows and small shield volcanoes. The submarine Reykjaneshryggur volcanic system is contiguous with and is considered part of the Reykjanes volcanic system, which is the westernmost of a series of four closely-spaced en-echelon fissure systems that extend diagonally across the Reykjanes Peninsula. Most of the subaerial part of the system (also known as the Reykjanes/Svartsengi volcanic system) is covered by Holocene lavas. Subaerial eruptions have occurred in historical time during the 13th century at several locations on the NE-SW-trending fissure system, and numerous submarine eruptions dating back to the 12th century have been observed during historical time, some of which have formed ephemeral islands. Basaltic rocks of probable Holocene age have been recovered during dredging operations, and tephra deposits from earlier Holocene eruptions are preserved on the nearby Reykjanes Peninsula. Sources: Icelandic Meteorological Office (IMO) http://en.vedur.is/ <https://urldefense.com/v3/__http://en.vedur.is/__;!!IKRxdwAv5BmarQ!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10Qil7hg4w$> ; Icelandic National Broadcasting Service (RUV) https://www.ruv.is/english/2024-08-22-eruption-on-reykjanes-peninsula-420082 <https://urldefense.com/v3/__https://www.ruv.is/english/2024-08-22-eruption-on-reykjanes-peninsula-420082__;!!IKRxdwAv5BmarQ!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10Ttkk9nMQ$> Sheveluch | Central Kamchatka (Russia) | 56.653°N, 161.36°E | Summit elev. 3283 m KVERT reported that during 19-22 August lava extrusion possibly continued at Sheveluchâ??s â??300 years of RASâ?? dome on the SW flank of Old Sheveluch and at a new vent or dome that formed during the 17-18 August explosive events. A weak thermal anomaly over the domes was identified in satellite images on 19 and 21 August. Resuspended ash from the S flank rose as high as 3 km (10,000 ft) a.s.l. and drifted 200 km SE during 20-21 August based on webcam and satellite images. 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!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10RfoAMeJA$> Whakaari/White Island | North Island (New Zealand) | 37.52°S, 177.18°E | Summit elev. 294 m GeoNet reported that minor eruptive activity at Whakaari/White Island during 21-27 August was characterized by elevated sulfur dioxide gas emissions and minor ash emissions. During a 21 August overflight, scientists observed gas, steam, and ash plumes rising 600-900 m from the new vent that had opened in early August. Ashfall on the island was seen within a 1 km radius of the vent. The temperature at the vent was about 590 degrees Celsius based on infrared images taken during the overflight. Low-level plumes containing minor amounts of ash were identified in satellite images and images from webcams located in Whakatane and Te Kaha during the week. In calm weather conditions the plumes were sometimes visible rising as high as 2 km a.s.l., and at other times drifted tens of kilometers downwind. During 22-23 August the plumes drifted towards the Bay of Plenty. According to a news report at least 10 flights in and out of both Tauranga and Rotorua Airports were cancelled and three were delayed during the morning on 22 August. The flight disruptions were a â??proactive safety measureâ?? and by 1130 airport operations were back to normal. The Volcanic Alert Level remained at 3 (on a scale of 0-5) and the Aviation Color Code remained at Orange (the second highest 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. Sources: GeoNet http://www.geonet.org.nz/ <https://urldefense.com/v3/__http://www.geonet.org.nz/__;!!IKRxdwAv5BmarQ!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10SSW5XA-w$> ; Radio New Zealand https://www.rnz.co.nz/news/national/525838/volcanic-cloud-from-whakaari-white-island-halts-flights <https://urldefense.com/v3/__https://www.rnz.co.nz/news/national/525838/volcanic-cloud-from-whakaari-white-island-halts-flights__;!!IKRxdwAv5BmarQ!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10TP6d38VQ$> Ongoing Activity Aira | Kyushu (Japan) | 31.5772°N, 130.6589°E | Summit elev. 1117 m JMA reported ongoing eruptive activity at Minamidake Crater (Aira Calderaâ??s Sakurajima volcano) during 19-26 August. Nighttime crater incandescence was visible in webcam images. Eruptive events at 0901 and 0926 on 21 August produced ash plumes that rose 1-1.4 km above the crater rim and drifted N. An explosion at 1457 on 21 August generated an ash plume that rose as high as 2.7 km and drifted N and ejected large blocks 800-1,200 m from the crater rim. Sulfur dioxide emissions were somewhat high that day, averaging 1,800 tons per day. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to stay 1 km away from both craters. Geologic Summary. The Aira caldera in the northern half of Kagoshima Bay contains the post-caldera Sakurajima volcano, one of Japan's most active. Eruption of the voluminous Ito pyroclastic flow accompanied formation of the 17 x 23 km caldera about 22,000 years ago. The smaller Wakamiko caldera was formed during the early Holocene in the NE corner of the caldera, along with several post-caldera cones. The construction of Sakurajima began about 13,000 years ago on the southern rim and built an island that was joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kitadake summit cone ended about 4,850 years ago, after which eruptions took place at Minamidake. Frequent eruptions since the 8th century have deposited ash on the city of Kagoshima, located across Kagoshima Bay only 8 km from the summit. The largest recorded eruption took place during 1471-76. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10QNHTsWvQ$> Dukono | Halmahera | 1.6992°N, 127.8783°E | Summit elev. 1273 m PVMBG reported that the eruption at Dukono was ongoing during 21-27 August. Gray-and-white ash plumes that were sometimes dense rose 100-900 m above the summit and drifted E and W on most days; white plumes rose 200-400 m above the summit and drifted W on 15 August, and no emissions were observed on 21 August likely due to weather conditions. 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!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10R-6UwYNA$> Ebeko | Paramushir Island (Russia) | 50.686°N, 156.014°E | Summit elev. 1103 m KVERT reported that moderate explosive activity was ongoing at Ebeko during 15-22 August. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E), explosions throughout the week generated ash plumes that rose as high as 2.5 km (8,200 ft) a.s.l. and drifted E. Thermal anomalies were identified in satellite images on 17 August; on other days either no activity was observed, or weather conditions prevented views. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates are UTC; specific events are in local time where noted. Geologic Summary. The flat-topped summit of the central cone of Ebeko volcano, one of the most active in the Kuril Islands, occupies the northern end of Paramushir Island. Three summit craters located along a SSW-NNE line form Ebeko volcano proper, at the northern end of a complex of five volcanic cones. Blocky lava flows extend west from Ebeko and SE from the neighboring Nezametnyi cone. The eastern part of the southern crater contains strong solfataras and a large boiling spring. The central crater is filled by a lake about 20 m deep whose shores are lined with steaming solfataras; the northern crater lies across a narrow, low barrier from the central crater and contains a small, cold crescentic lake. Historical activity, recorded since the late-18th century, has been restricted to small-to-moderate explosive eruptions from the summit craters. Intense fumarolic activity occurs in the summit craters, on the outer flanks of the cone, and in lateral explosion craters. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10RfoAMeJA$> Great Sitkin | Andreanof Islands (USA) | 52.076°N, 176.13°W | Summit elev. 1740 m AVO reported that slow lava effusion in Great Sitkinâ??s summit crater continued during 21-27 August. Seismicity was low with few small daily earthquakes. Nothing unusual was observed in satellite and webcam images throughout the week. Weakly elevated surface temperatures were detected in satellite data during 26-27 August, consistent with a cooling lava flow. 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!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10RLbRMuRA$> Ibu | Halmahera | 1.488°N, 127.63°E | Summit elev. 1325 m PVMBG reported that activity at Ibu continued during 14-20 August with multiple eruptive events recorded daily. Daily gray or white-and-gray ash plumes that were sometimes dense generally rose as high as 2 km above the summit and drifted N, NW, W, and SW. Some webcam images posted with the reports showed incandescence emanating above the crater rim, possibly reflected in the emissions. At 0118 on 28 August a dense gray-to-black ash plume rose as high as 5 km above the crater rim and drifted SW and W. The Alert Level remained at 3 (the second highest level on a four-level scale) and the public was advised to stay 4 km away from the active crater and 5 km away from the N crater wall opening. Geologic Summary. The truncated summit of Gunung Ibu stratovolcano along the NW coast of Halmahera Island has large nested summit craters. The inner crater, 1 km wide and 400 m deep, has contained several small crater lakes. The 1.2-km-wide outer crater is breached on the N, creating a steep-walled valley. A large cone grew ENE of the summit, and a smaller one to the WSW has fed a lava flow down the W flank. A group of maars is located below the N and W flanks. The first observed and recorded eruption was a small explosion from the summit crater in 1911. Eruptive activity began again in December 1998, producing a lava dome that eventually covered much of the floor of the inner summit crater along with ongoing explosive ash emissions. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10R-6UwYNA$> Kanlaon | Philippines | 10.4096°N, 123.13°E | Summit elev. 2422 m PHIVOLCS issued special notices for Kanlaon noting continuing high levels sulfur dioxide gas emissions. Summit emissions measured with a Flyspec instrument averaged 6,720 tonnes/day (t/d), 6,367 t/d, and 7,172 t/d on 21, 24, and 25 August, respectively. Sulfur odors were reported in several barangays (neighborhoods) in La Carlota City (14 km W) and La Castellana (16 km SW), Negros Occidental, on 21 August and in Murcia (17 km NNW), Negros Occidental, on 24 August. Voluminous steam-rich plumes were observed on 24 August rising as high as 700 m above the crater rim and drifting N. The 25 August measurement was the second highest emission average ever recorded at the volcano. Sulfur dioxide emissions decreased to 3,447 t/d on 26 August. Higher sulfur dioxide gas fluxes had been recorded in 2024 with an average of 1,273 t/d prior to the 3 June eruption; afterward the eruption emissions were elevated, averaging 3,351 t/d. An average of nine volcanic earthquakes per day also persisted after the 3 June eruption. Ground deformation data from continuous GPS and electronic tilt data indicated slow inflation of the volcano since March 2022; the rate of inflation at the E flank increased in 2023 and at the SE flank beginning in July 2024. The Alert Level remained at 1 (on a scale of 0-5) and PHIVOLCS reminded the public to remain outside of the 4-km-radius Permanent Danger Zone. 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!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10RT4ivjhQ$> Karymsky | Eastern Kamchatka (Russia) | 54.049°N, 159.443°E | Summit elev. 1513 m KVERT reported moderate levels of activity at Karymsky during 15-22 August. A thermal anomaly over the volcano was identified in satellite images on 16 August; weather clouds obscured views on the other days during the week. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted. Geologic Summary. Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed during the early Holocene. The caldera cuts the south side of the Pleistocene Dvor volcano and is located outside the north margin of the large mid-Pleistocene Polovinka caldera, which contains the smaller Akademia Nauk and Odnoboky calderas. Most seismicity preceding Karymsky eruptions originated beneath Akademia Nauk caldera, located immediately south. The caldera enclosing Karymsky formed about 7600-7700 radiocarbon years ago; construction of the stratovolcano began about 2000 years later. The latest eruptive period began about 500 years ago, following a 2300-year quiescence. Much of the cone is mantled by lava flows less than 200 years old. Historical eruptions have been vulcanian or vulcanian-strombolian with moderate explosive activity and occasional lava flows from the summit crater. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10RfoAMeJA$> Lewotobi | Flores Island | 8.542°S, 122.775°E | Summit elev. 1703 m PVMBG reported that eruptive activity at Lewotobiâ??s Laki-laki volcano continued during 21-27 August. Daily gray or white-and-gray ash plumes that were sometimes dense rose as high as 1.2 km above the summit and drifted mainly SW, W, and NW. According to a 23 August news article farmers reported failed crops, including cashews, that had been impacted by ashfall. Another news article stated that several local homes were flooded on 25 August by lahars that had a sulfur odor. 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. 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!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10R-6UwYNA$> ; Metro TV News https://www.metrotvnews.com/read/NxGCzBPj-erupsi-gunung-lewotobi-bikin-petani-gagal-panen-jambu-mete <https://urldefense.com/v3/__https://www.metrotvnews.com/read/NxGCzBPj-erupsi-gunung-lewotobi-bikin-petani-gagal-panen-jambu-mete__;!!IKRxdwAv5BmarQ!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10TMxxvSXw$> ; Metro TV News https://www.metrotvnews.com/read/b1oC9nwn-rumah-warga-di-lereng-gunung-lewotobi-tergenang-air-campur-lumpur <https://urldefense.com/v3/__https://www.metrotvnews.com/read/b1oC9nwn-rumah-warga-di-lereng-gunung-lewotobi-tergenang-air-campur-lumpur__;!!IKRxdwAv5BmarQ!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10QS9cx8gQ$> Marapi | Central Sumatra | 0.38°S, 100.474°E | Summit elev. 2885 m PVMBG reported that eruptive activity at Marapi (on Sumatra) was ongoing during 21-17 August. Gray ash plumes rose 100-350 m above the summit and drifted in multiple directions during 21-22 and 25 August. Emissions were not observed on the other days. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay 3 km away from the active crater. Geologic Summary. Gunung Marapi, not to be confused with the better-known Merapi volcano on Java, is Sumatra's most active volcano. This massive complex stratovolcano rises 2,000 m above the Bukittinggi Plain in the Padang Highlands. A broad summit contains multiple partially overlapping summit craters constructed within the small 1.4-km-wide Bancah caldera. The summit craters are located along an ENE-WSW line, with volcanism migrating to the west. More than 50 eruptions, typically consisting of small-to-moderate explosive activity, have been recorded since the end of the 18th century; no lava flows outside the summit craters have been reported in historical time. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10R-6UwYNA$> Merapi | Central Java | 7.54°S, 110.446°E | Summit elev. 2910 m BPPTKG reported that the eruption at Merapi (on Java) continued during 16-22 August. Earthquakes were more intense compared to the previous week. The SW lava dome produced lava avalanches that descended the S and SW flanks; 314 traveled as far as 1.9 km SW down the upper part of the Bebeng drainage, two traveled 1 km S down the Boyong drainage, one traveled 1 km W down the Batang drainage, and one traveled 500 m W down the Apu drainage. Morphological changes to the SW lava dome were due to continuing effusion and collapses of material. The volume of the SW dome was an estimated 2,777,900 cubic meters based on webcam images and a 21 August drone survey. The hottest temperature was around 243 degrees Celsius, similar to the previous measurement. 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!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10SE__z3RA$> Sabancaya | Peru | 15.787°S, 71.857°W | Summit elev. 5960 m Instituto GeofÃsico del Perú (IGP) reported that the eruption at Sabancaya continued during 9-25 August with a daily average of 58 explosions. Gas-and-ash plumes rose as high as 2 km above the summit and drifted less than 10 km NE, SE, and S. Thermal anomalies over the lava dome in the summit crater were identified in satellite data. Slight inflation was detected N of Hualca Hualca (7 km N). Sulfur dioxide emissions were at moderate levels, averaging 585 tons per day. The Alert Level remained at Orange (the third level on a four-color scale) and the public was warned to stay outside of a 12 km radius. Geologic Summary. Sabancaya, located in the saddle NE of Ampato and SE of Hualca Hualca volcanoes, is the youngest of these volcanic centers and the only one to have erupted in historical time. The oldest of the three, Nevado Hualca Hualca, is of probable late-Pliocene to early Pleistocene age. The name Sabancaya (meaning "tongue of fire" in the Quechua language) first appeared in records in 1595 CE, suggesting activity prior to that date. Holocene activity has consisted of Plinian eruptions followed by emission of voluminous andesitic and dacitic lava flows, which form an extensive apron around the volcano on all sides but the south. Records of observed eruptions date back to 1750 CE. Source: Instituto GeofÃsico del Perú (IGP) http://www.igp.gob.pe/ <https://urldefense.com/v3/__http://www.igp.gob.pe/__;!!IKRxdwAv5BmarQ!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10TnqIRX2Q$> Semeru | Eastern Java | 8.108°S, 112.922°E | Summit elev. 3657 m PVMBG reported that eruptive activity continued at Semeru during 21-27 August with multiple daily eruptive events recorded by the seismic network. White-and-gray ash plumes that were sometimes dense rose 100-800 m above the summit and drifted S, SW, and W on most days; weather conditions sometimes prevented visual confirmation of the eruptive events, especially on 21 and 25 August. 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!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10R-6UwYNA$> Stromboli | Aeolian Islands (Italy) | 38.789°N, 15.213°E | Summit elev. 924 m INGV reported that eruptive activity continued at Stromboli during 19-25 August. Webcam images showed Strombolian activity at three vents in Area N within the upper part of the Sciara del Fuoco, and from one vent at S2 in Area C-S (South-Central Crater) on the crater terrace. The vents in Area N had been active for several weeks and two of them continued to produce explosions ejecting ash, lapilli, and bombs. The third and southernmost vent ejected spatter. A larger explosion at 1140 on 25 August produced a dense ash plume and ejected material onto the Sciara del Fuoco drainage. The vent in Area C-S ejected tephra at a decreasing rate. The Dipartimento della Protezione Civile lowered the Alert Level to Orange on 23 July and then to Yellow (the second lowest level on a four-level scale) on 8 August, where it remains. 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!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10RvM789iQ$> ; Dipartimento della Protezione Civile https://www.protezionecivile.gov.it/it/ <https://urldefense.com/v3/__https://www.protezionecivile.gov.it/it/__;!!IKRxdwAv5BmarQ!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10SSnlmoKg$> Suwanosejima | Ryukyu Islands (Japan) | 29.638°N, 129.714°E | Summit elev. 796 m JMA reported that eruptive activity at Suwanosejima's Ontake Crater continued during 19-26 August. Crater incandescence was observed nightly in webcam images. An explosion at 0900 on 22 August generated an ash plume that rose 1.5 km straight up above the crater rim. An eruptive event at 0448 on 25 August generated an ash plume that rose 2.3 km above the carter rim and drifted S. An ash plume from an explosion at 1623 on 26 August rose 1.3 km above the crater rim and drifted SW. The Alert Level remained at 2 (on a 5-level scale) and the public was warned to stay at least 1.5 km away from the crater. Geologic Summary. The 8-km-long island of Suwanosejima in the northern Ryukyu Islands consists of an andesitic stratovolcano with two active summit craters. The summit is truncated by a large breached crater extending to the sea on the E flank that was formed by edifice collapse. One of Japan's most frequently active volcanoes, it was in a state of intermittent Strombolian activity from Otake, the NE summit crater, between 1949 and 1996, after which periods of inactivity lengthened. The largest recorded eruption took place in 1813-14, when thick scoria deposits covered residential areas, and the SW crater produced two lava flows that reached the western coast. At the end of the eruption the summit of Otake collapsed, forming a large debris avalanche and creating an open collapse scarp extending to the eastern coast. The island remained uninhabited for about 70 years after the 1813-1814 eruption. Lava flows reached the eastern coast of the island in 1884. Only about 50 people live on the island. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10QNHTsWvQ$> Villarrica | Central Chile | 39.42°S, 71.93°W | Summit elev. 2847 m Servicio Nacional de GeologÃa y MinerÃa (SERNAGEOMIN) and Nacional de Prevención y Repuesta Ante Desastres (SENAPRED) reduced the exclusion zone around Villarrica to 1 km on 23 August. The announcement noted that there had been a decrease in the number of explosions that ejected material above the crater rim and that monitoring data had showed low levels of activity for the previous few months. The Volcanic Alert Level remained at Yellow (the second lowest level on a four-level scale) and SENAPRED maintained the Alert Level at Yellow (the middle level on a three-color scale) for the communities of Villarrica, Pucón (16 km N), Curarrehue, and Panguipulli. Geologic Summary. The glacier-covered Villarrica stratovolcano, in the northern Lakes District of central Chile, is ~15 km south of the city of Pucon. A 2-km-wide caldera that formed about 3,500 years ago is located at the base of the presently active, dominantly basaltic to basaltic-andesite cone at the NW margin of a 6-km-wide Pleistocene caldera. More than 30 scoria cones and fissure vents are present on the flanks. Plinian eruptions and pyroclastic flows that have extended up to 20 km from the volcano were produced during the Holocene. Lava flows up to 18 km long have issued from summit and flank vents. Eruptions documented since 1558 CE have consisted largely of mild-to-moderate explosive activity with occasional lava effusion. Glaciers cover 40 km2 of the volcano, and lahars have damaged towns on its flanks. Sources: Servicio Nacional de GeologÃa y MinerÃa (SERNAGEOMIN) http://www.sernageomin.cl/ <https://urldefense.com/v3/__http://www.sernageomin.cl/__;!!IKRxdwAv5BmarQ!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10Q10d2aiQ$> ; Sistema y Servicio Nacional de Prevención y Repuesta Ante Desastres (SENAPRED) https://senapred.cl/ <https://urldefense.com/v3/__https://senapred.cl/__;!!IKRxdwAv5BmarQ!e2j-Wg9FNK5D8DANhyNvsh_y9UEH4ZkQuBmoZJOmMg4NtJ4xx5ZR1k1w3Dwmfozm8l0q0i6lAn_FDmHE10QKjEoppQ$> 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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