4-4-4-4-4-4-4-4-4-4-4-4-4 From: "Kuhn, Sally" <KUHNS@xxxxxx> Smithsonian / USGS Weekly Volcanic Activity Report 18-24 May 2022 Sally Kuhn Sennert - Weekly Report Editor (kuhns@xxxxxx) URL: https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKU93awlw$ <https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFiuneew0$> New Activity/Unrest: Bezymianny, Central Kamchatka (Russia) | Cleveland, Chuginadak Island (USA) | Krakatau, Sunda Strait | Reykjanes, Reykjanes Peninsula Ongoing Activity: Aira, Kyushu (Japan) | Dukono, Halmahera | Etna, Sicily (Italy) | Fuego, South-Central Guatemala | Great Sitkin, Andreanof Islands (USA) | Ibu, Halmahera | Karymsky, Eastern Kamchatka (Russia) | Katmai, Alaska | Kilauea, Hawaiian Islands (USA) | Lewotolok, Lembata Island | Manam, Northeast of New Guinea | Merapi, Central Java | Nevados de Chillan, Central Chile | Pavlof, Alaska Peninsula, Alaska | Rincon de la Vieja, Costa Rica | Ruapehu, North Island (New Zealand) | Semeru, Eastern Java | Semisopochnoi, Aleutian Islands (USA) | Sheveluch, Central Kamchatka (Russia) | Suwanosejima, Ryukyu Islands (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 Bezymianny | Central Kamchatka (Russia) | 55.972°N, 160.595°E | Summit elev. 2882 m On 24 May KVERT reported that the effusive eruption at Bezymianny continued, characterized by strong fumarolic emissions, lava-dome incandescence, and hot avalanches. Notable hot avalanches descended the E flank. Gas-and-steam plumes with some ash content drifted 30 km NW on 24 May and 25 km NE on 25 May, at altitudes of 3-4.5 km (9,800-14,800 ft) a.s.l. The Aviation Color Code was raised to 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. Prior to its noted 1955-56 eruption, Bezymianny had been considered extinct. The modern volcano, much smaller in size than its massive neighbors Kamen and Kliuchevskoi, was formed about 4700 years ago over a late-Pleistocene lava-dome complex and an ancestral edifice built about 11,000-7000 years ago. Three periods of intensified activity have occurred during the past 3000 years. The latest period, which was preceded by a 1000-year quiescence, began with the dramatic 1955-56 eruption. This eruption, similar to that of St. Helens in 1980, produced a large horseshoe-shaped 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) https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKapqUoMl$ <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFOBNbD9E$> Cleveland | Chuginadak Island (USA) | 52.825°N, 169.944°W | Summit elev. 1730 m AVO reported that during 17-24 May almost daily elevated surface temperatures over Cleveland were identified in satellite images. Daily sulfur dioxide emissions were visible, and steam plumes rose from the crater during 22-24 May. A series of small, local earthquakes were detected on 18 May. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory. Geologic Summary. The beautifully symmetrical Mount Cleveland stratovolcano is situated at the western end of the uninhabited Chuginadak Island. It lies SE across Carlisle Pass strait from Carlisle volcano and NE across Chuginadak Pass strait from Herbert volcano. Joined to the rest of Chuginadak Island by a low isthmus, Cleveland is the highest of the Islands of the Four Mountains group and is one of the most active of the Aleutian Islands. The native name, Chuginadak, refers to the Aleut goddess of fire, who was thought to reside on the volcano. Numerous large lava flows descend the steep-sided flanks. It is possible that some 18th-to-19th century eruptions attributed to Carlisle should be ascribed to Cleveland (Miller et al., 1998). In 1944 it produced the only known fatality from an Aleutian eruption. Recent eruptions have been characterized by short-lived explosive ash emissions, at times accompanied by lava fountaining and lava flows down the flanks. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKRDCJmPL$ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFeGfIzX0$> Krakatau | Sunda Strait | 6.102°S, 105.423°E | Summit elev. 155 m The Darwin VAAC reported that on 18 May a diffuse ash plume from Anak Krakatau rose to 2.4 km (8,000 ft) a.s.l. and drifted WNW based on satellite images and weather models. On 19 May a dense steam plume with diffuse ash rose to 2.4 km and drifted N. Geologic Summary. The renowned volcano Krakatau (frequently misstated as Krakatoa) lies in the Sunda Strait between Java and Sumatra. Collapse of the ancestral Krakatau edifice, perhaps in 416 or 535 CE, formed a 7-km-wide caldera. Remnants of this ancestral volcano are preserved in Verlaten and Lang Islands; subsequently Rakata, Danan, and Perbuwatan volcanoes were formed, coalescing to create the pre-1883 Krakatau Island. Caldera collapse during the catastrophic 1883 eruption destroyed Danan and Perbuwatan, and left only a remnant of Rakata. This eruption, the 2nd largest in Indonesia during historical time, caused more than 36,000 fatalities, most as a result of devastating tsunamis that swept the adjacent coastlines of Sumatra and Java. Pyroclastic surges traveled 40 km across the Sunda Strait and reached the Sumatra coast. After a quiescence of less than a half century, the post-collapse cone of Anak Krakatau (Child of Krakatau) was constructed within the 1883 caldera at a point between the former cones of Danan and Perbuwatan. Anak Krakatau has been the site of frequent eruptions since 1927. Source: Darwin Volcanic Ash Advisory Centre (VAAC) https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKYEe2Vwf$ <https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFqrrntZU$> Reykjanes | Reykjanes Peninsula | 63.817°N, 22.717°W | Summit elev. 140 m IMO reported an ongoing seismic swarm and uplift on the Reykjanes Peninsula, indicative of a magma intrusion. Satellite data analysis indicated that 4-4.5 cm of uplift occurred during 27 April-21 May centered just NW of Mt. Thorbjorn. Magma was accumulating at depths of 4-5 km, and the intrusion was possibly 7-8 km long. During 22-23 May about 400 earthquakes were recorded; a M 3 earthquake was recorded at 1113 on 22 May and a M 3.5 earthquake was recorded at 0715 on 23 May, both were located about 3 km E of Mt. Thorbjorn. The Aviation Color Code for Reykjanes remained at Yellow. Geologic Summary. The Reykjanes volcanic system at the SW tip of the Reykjanes Peninsula, where the Mid-Atlantic Ridge rises above sea level, comprises a broad area of postglacial basaltic crater rows and small shield volcanoes. The submarine Reykjaneshryggur volcanic system is contiguous with and is considered part of the Reykjanes volcanic system, which is the westernmost of a series of four closely-spaced en-echelon fissure systems that extend diagonally across the Reykjanes Peninsula. Most of the subaerial part of the system (also known as the Reykjanes/Svartsengi volcanic system) is covered by Holocene lavas. Subaerial eruptions have occurred in historical time during the 13th century at several locations on the NE-SW-trending fissure system, and numerous submarine eruptions dating back to the 12th century have been observed during historical time, some of which have formed ephemeral islands. Basaltic rocks of probable Holocene age have been recovered during dredging operations, and tephra deposits from earlier Holocene eruptions are preserved on the nearby Reykjanes Peninsula. Sources: Icelandic Meteorological Office (IMO) https://urldefense.com/v3/__http://en.vedur.is/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKS7tw_fA$ <https://urldefense.com/v3/__http://en.vedur.is/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wF8RmVz7E$> ; Icelandic National Broadcasting Service (RUV) https://urldefense.com/v3/__https://www.ruv.is/frett/2022/05/19/magma-accumulating-underground?term=earthquake__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKabE4Ke1$ <https://urldefense.com/v3/__https://www.ruv.is/frett/2022/05/19/magma-accumulating-underground?term=earthquake__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFN_NaoGs$> Ongoing Activity Aira | Kyushu (Japan) | 31.593°N, 130.657°E | Summit elev. 1117 m JMA reported that a very small eruptive event was recorded at Minamidake Crater (at Aira Calderaâ??s Sakurajima volcano) during 16-23 May. Crater incandescence was visible at night. At 0900 on 17 May an eruptive event produced a plume that rose 1.5 km above the crater rim. That same day the sulfur dioxide rate was slightly high at 1,700 tons per day. The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from the crater. Geologic Summary. The Aira caldera in the northern half of Kagoshima Bay contains the post-caldera Sakurajima volcano, one of Japan's most active. Eruption of the voluminous Ito pyroclastic flow accompanied formation of the 17 x 23 km caldera about 22,000 years ago. The smaller Wakamiko caldera was formed during the early Holocene in the NE corner of the Aira caldera, along with several post-caldera cones. The construction of Sakurajima began about 13,000 years ago on the southern rim of Aira caldera and built an island that was finally joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kitadake summit cone ended about 4850 years ago, after which eruptions took place at Minamidake. Frequent historical eruptions, recorded since the 8th century, have deposited ash on Kagoshima, one of Kyushu's largest cities, located across Kagoshima Bay only 8 km from the summit. The largest historical eruption took place during 1471-76. Source: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKXKK3DpI$ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wF-u7uzcM$> Dukono | Halmahera | 1.693°N, 127.894°E | Summit elev. 1229 m Based on satellite and wind model data, the Darwin VAAC reported that during 17-20 May ash plumes from Dukono rose to 2.1-2.4 km (7,000-8,000 ft) a.s.l. and drifted W and NW. The plumes on 17 May drifted 185 km W. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone. Geologic Summary. Reports from this remote volcano in northernmost Halmahera are rare, but Dukono has been one of Indonesia's most active volcanoes. More-or-less continuous explosive eruptions, sometimes accompanied by lava flows, occurred from 1933 until at least the mid-1990s, when routine observations were curtailed. During a major eruption in 1550, a lava flow filled in the strait between Halmahera and the north-flank cone of Gunung Mamuya. This complex volcano presents a broad, low profile with multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of the summit crater complex, contains a 700 x 570 m crater that has also been active during historical time. Sources: Darwin Volcanic Ash Advisory Centre (VAAC) https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKYEe2Vwf$ <https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFqrrntZU$> ; Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKdE2f3eY$ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFLTI-t4Y$> Etna | Sicily (Italy) | 37.748°N, 14.999°E | Summit elev. 3320 m INGV reported that at around 1900 on 12 May a new vent opened along the N flank of Etnaâ??s Southeast Crater (SEC) at an elevation of 3,250 m, and produced ash emissions that rose to 3.5 km (11,500 ft) a.s.l. and drifted SW. Small pyroclastic flows descended the flank. Lava effused from the vent and traveled N and NE into the snowy Valle del Leone, where lava blocks that rolled onto the snow caused steam plumes. The lava flow slowly advanced during 13-22 May, reaching 2,300-2,400 m elevation by 17 May. Discontinuous Strombolian activity of variable intensities occurred at SEC; ash emissions were visible during more intense phases, though the plumes dissipated rapidly. A new lava flow emerged from the vent on the N flank at around 2300 on 17 May and traveled N and NE alongside the previous lava flow. During fieldwork conducted on 18 May, scientists observed that lava had reached an elevation of 2,700 m in the Valle del Leone. A new vent opened on the N flank of SEC by 1730 on 20 May, at 3,250 m elevation, just NW of the previous vent. The vent produced a small lava flow that curved N and NE, joining the previous flow. By 21 May lava flows were not advancing below the summit area, at elevations of 2,700-2,800. Strombolian activity of varying intensity continued at SEC; periodic ash emissions generated ashfall in areas as far as Catania. At 2305 on 21 May a pyroclastic flow from the 20 May vent traveled 700 m NNE. Ash emissions intensified during 0300-0400 on 22 May. By that evening, lava flows from the 12 May vent had ceased and the 20 May vent produced short lava flows. Geologic Summary. Mount Etna, towering above Catania, Sicily's second largest city, has one of the world's longest documented records of historical 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 horseshoe-shaped 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) https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKeOL-NWs$ <https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFFuC5biE$> Fuego | South-Central Guatemala | 14.473°N, 90.88°W | Summit elev. 3763 m INSIVUMEH reported that on 23 May lahars descended Fuego in the Las Lajas drainage (SE), the Ceniza drainage (SSW), and the Honda drainage (E); all three lahars carried fine material along with tree trunks, branches, and blocks as large as 1.5 m in diameter. Geologic Summary. Volcán Fuego, one of Central America's most active volcanoes, is also one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between Fuego and Acatenango to the north. Construction of Meseta dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta may have produced the massive Escuintla debris-avalanche deposit, which extends about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at the mostly andesitic Acatenango. Eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. Frequent vigorous historical eruptions have been recorded since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH) https://urldefense.com/v3/__http://www.insivumeh.gob.gt/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKWUwErym$ <https://urldefense.com/v3/__http://www.insivumeh.gob.gt/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFWC1wiOg$> Great Sitkin | Andreanof Islands (USA) | 52.076°N, 176.13°W | Summit elev. 1740 m AVO reported that the eruption at Great Sitkin continued during 17-24 May. Almost daily elevated surface temperatures were identified in satellite data, consistent with lava effusion. Steam emissions were visible during 23-24 May. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively. Geologic Summary. The Great Sitkin volcano forms much of the northern side of Great Sitkin Island. A younger parasitic volcano capped by a small, 0.8 x 1.2 km ice-filled summit caldera was constructed within a large late-Pleistocene or early Holocene scarp formed by massive edifice failure that truncated an ancestral volcano and produced a submarine debris avalanche. Deposits from this and an older debris avalanche from a source to the south cover a broad area of the ocean floor north of the volcano. The summit lies along the eastern rim of the younger collapse scarp. Deposits from an earlier caldera-forming eruption of unknown age cover the flanks of the island to a depth up to 6 m. The small younger caldera was partially filled by lava domes emplaced in 1945 and 1974, and five small older flank lava domes, two of which lie on the coastline, were constructed along northwest- and NNW-trending lines. Hot springs, mud pots, and fumaroles occur near the head of Big Fox Creek, south of the volcano. Historical eruptions have been recorded since the late-19th century. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKRDCJmPL$ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFeGfIzX0$> Ibu | Halmahera | 1.488°N, 127.63°E | Summit elev. 1325 m PVMBG reported that the eruption at Ibu continued during 17-24 May. Daily gray-and-white ash plumes of variable densities generally rose 200-1,500 m above the summit and drifted in multiple directions. The Alert Level remained at a 2 (on a scale of 1-4), and the public was warned to stay at least 2 km away from the active crater and 3.5 km away on the N side. Geologic Summary. The truncated summit of Gunung Ibu stratovolcano along the NW coast of Halmahera Island has large nested summit craters. The inner crater, 1 km wide and 400 m deep, has contained several small crater lakes. The 1.2-km-wide outer crater is breached on the N, creating a steep-walled valley. A large cone grew ENE of the summit, and a smaller one to the WSW has fed a lava flow down the W flank. A group of maars is located below the N and W flanks. The first observed and recorded eruption was a small explosion from the summit crater in 1911. Eruptive activity began again in December 1998, producing a lava dome that eventually covered much of the floor of the inner summit crater along with ongoing explosive ash emissions. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKdE2f3eY$ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFLTI-t4Y$> Karymsky | Eastern Kamchatka (Russia) | 54.049°N, 159.443°E | Summit elev. 1513 m KVERT reported that during 13-20 May daily explosions at Karymsky generated ash plumes that rose 3-9.5 km (9,800-31,200 ft) a.s.l. and drifted more than 450 km in various directions. A thermal anomaly over the volcano was visible in satellite images during 13-14 and 17-19 May. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted. Geologic Summary. Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed during the early Holocene. The caldera cuts the south side of the Pleistocene Dvor volcano and is located outside the north margin of the large mid-Pleistocene Polovinka caldera, which contains the smaller Akademia Nauk and Odnoboky calderas. Most seismicity preceding Karymsky eruptions originated beneath Akademia Nauk caldera, located immediately south. The caldera enclosing Karymsky formed about 7600-7700 radiocarbon years ago; construction of the stratovolcano began about 2000 years later. The latest eruptive period began about 500 years ago, following a 2300-year quiescence. Much of the cone is mantled by lava flows less than 200 years old. Historical eruptions have been vulcanian or vulcanian-strombolian with moderate explosive activity and occasional lava flows from the summit crater. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKapqUoMl$ <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFOBNbD9E$> Katmai | Alaska | 58.28°N, 154.963°W | Summit elev. 2047 m AVO reported that on 20 May strong winds in the vicinity of Katmai and the Valley of Ten Thousand Smokes blew unconsolidated ash WNW at an altitude up to 1.8 km (6,000 ft) a.s.l. The ash was originally deposited during the Novarupta eruption in 1912. The Volcano Alert Level remained at Normal and the Aviation Color Code remained at Green. Geologic Summary. Prior to 1912, Mount Katmai was a compound stratovolcano with four NE-SW-trending summits, most of which were truncated by caldera collapse in that year. Two or more large explosive eruptions took place from Mount Katmai during the late Pleistocene. Most of the two overlapping pre-1912 Katmai volcanoes are Pleistocene in age, but Holocene lava flows from a flank vent descend the SE flank of the SW stratovolcano into the Katmai River canyon. Katmai was initially considered to be the source of the Valley of Ten Thousand Smokes ash flow in 1912. However, the 3 x 4 km wide caldera of 1912 is now known to have formed as a result of the voluminous eruption at nearby Novarupta volcano. The steep walled young caldera has a jagged rim that rises 500-1000 m above the caldera floor and contains a 250-m-deep, still-rising lake. Lake waters have covered a small post-collapse lava dome (Horseshoe Island) that was seen on the caldera floor at the time of the initial ascent to the caldera rim in 1916. Post-1912 glaciers have formed on a bench within Katmai caldera. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKRDCJmPL$ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFeGfIzX0$> Kilauea | Hawaiian Islands (USA) | 19.421°N, 155.287°W | Summit elev. 1222 m HVO reported that lava continued to effuse from a vent in the lower W wall of Kilaueaâ??s Halema`uma`u Crater during 17-24 May, entering the active lava lake and flowing onto the crater floor. The surface of the lava lake was active all week, though the height of the lake was high and relatively stable. Breakouts of lava occurred along the E, N, NW, and W margins of the lake. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively. Geologic Summary. Kilauea overlaps the E flank of the massive Mauna Loa shield volcano in the island of Hawaii. Eruptions are prominent in Polynesian legends; written documentation since 1820 records frequent summit and flank lava flow eruptions interspersed with periods of long-term lava lake activity at Halemaumau crater in the summit caldera until 1924. The 3 x 5 km caldera was formed in several stages about 1,500 years ago and during the 18th century; eruptions have also originated from the lengthy East and Southwest rift zones, which extend to the ocean in both directions. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1,100 years old; 70% of the surface is younger than 600 years. The long-term eruption from the East rift zone between 1983 and 2018 produced lava flows covering more than 100 km2, destroyed hundreds of houses, and added new coastline. Source: US Geological Survey Hawaiian Volcano Observatory (HVO) https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKfk6njXs$ <https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wF_v618b8$> Lewotolok | Lembata Island | 8.274°S, 123.508°E | Summit elev. 1431 m PVMBG reported that the eruption at Lewotolok continued during 17-24 May. Daily white steam plumes were visible rising 50-800 m above the summit and drifted multiple directions. White-and-gray emissions were visible on 19 and 21 May rose as high as 500 m above the summit and drifted SE, W, and NW. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 3 km away from the summit crater and 4 km away from the crater on the SE flank. Geologic Summary. The Lewotolok (or Lewotolo) stratovolcano occupies the eastern end of an elongated peninsula extending north into the Flores Sea, connected to Lembata (formerly Lomblen) Island by a narrow isthmus. It is symmetrical when viewed from the north and east. A small cone with a 130-m-wide crater constructed at the SE side of a larger crater forms the volcano's high point. Many lava flows have reached the coastline. Eruptions recorded since 1660 have consisted of explosive activity from the summit crater. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKdE2f3eY$ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFLTI-t4Y$> Manam | Northeast of New Guinea | 4.08°S, 145.037°E | Summit elev. 1807 m The Darwin VAAC reported that during 17-19 May ash plumes from Manam rose to 2.4 km (8,000 ft) a.s.l. and drifted NW and W based on satellite images and weather models. Geologic Summary. The 10-km-wide island of Manam, lying 13 km off the northern coast of mainland Papua New Guinea, is one of the country's most active volcanoes. Four large radial valleys extend from the unvegetated summit of the conical basaltic-andesitic stratovolcano to its lower flanks. These valleys channel lava flows and pyroclastic avalanches that have sometimes reached the coast. Five small satellitic centers are located near the island's shoreline on the northern, southern, and western sides. Two summit craters are present; both are active, although most observed eruptions have originated from the southern crater, concentrating eruptive products during much of the past century into the SE valley. Frequent eruptions, typically of mild-to-moderate scale, have been recorded since 1616. Occasional larger eruptions have produced pyroclastic flows and lava flows that reached flat-lying coastal areas and entered the sea, sometimes impacting populated areas. Source: Darwin Volcanic Ash Advisory Centre (VAAC) https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKYEe2Vwf$ <https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFqrrntZU$> Merapi | Central Java | 7.54°S, 110.446°E | Summit elev. 2910 m BPPTKG reported that the eruption at Merapi continued during 13-19 May. The heights and morphologies of the SW lava dome and the central lava dome were unchanged from the previous week, and seismicity remained at high levels. As many as 82 lava avalanches traveled a maximum of 2 km, mostly down the Bebeng drainage on the SW flank. One pyroclastic flow traveled 2.5 km down the Bebeng drainage. Seismicity remained high. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-7 km away from the summit based on location. Geologic Summary. Merapi, one of Indonesia's most active volcanoes, lies in one of the world's most densely populated areas and dominates the landscape immediately north of the major city of Yogyakarta. It is the youngest and southernmost of a volcanic chain extending NNW to Ungaran volcano. Growth of Old Merapi during the Pleistocene ended with major edifice collapse perhaps about 2,000 years ago, leaving a large arcuate scarp cutting the eroded older Batulawang volcano. Subsequent growth of the steep-sided Young Merapi edifice, its upper part unvegetated due to frequent activity, began SW of the earlier collapse scarp. Pyroclastic flows and lahars accompanying growth and collapse of the steep-sided active summit lava dome have devastated cultivated lands on the western-to-southern flanks and caused many fatalities. Source: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG) https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKVsx9YJU$ <https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFgWv3ZJQ$> Nevados de Chillan | Central Chile | 36.868°S, 71.378°W | Summit elev. 3180 m SERNAGEOMIN reported low levels of activity at Nevados de Chillán during 1-15 May. The area of the lava dome on the floor of Nicanor Crater was 1,626 square meters, similar to measurements from March (1,665 square meters); deformation measurements indicated that extrusion had ceased. Crater incandescence was sometimes visible; thermal anomalies were identified in satellite images on 3, 5, 8, 10, 13, and 15 May. There were 217 explosions in the active crater recorded by the seismic network. The explosions mainly produced steam, though the plumes occasionally contained tephra. Material from explosive activity accumulated in the NE part of the crater. An energetic explosion on 16 May produced an ash plume that rose 900 m and pyroclastic flows that descended the SE, NE, and W flanks as far as 400 m. Seismicity remained at moderate levels. Sulfur dioxide emissions averaged 466 ± 54 tons per day, peaking at 802 tons per day on 7 May. An explosion was recorded on 21 May. The Alert Level remained at Yellow, the second lowest level on a four-color scale. ONEMI stated that Alert Level Yellow (the middle level on a three-color scale) remained in place for the communities of Pinto and Coihueco, noting that the public should stay at least 2 km away from the crater. Geologic Summary. The compound volcano of Nevados de Chillán is one of the most active of the Central Andes. Three late-Pleistocene to Holocene stratovolcanoes were constructed along a NNW-SSE line within three nested Pleistocene calderas, which produced ignimbrite sheets extending more than 100 km into the Central Depression of Chile. The dominantly andesitic Cerro Blanco (Volcán Nevado) stratovolcano is located at the NW end of the massif. Volcán Viejo (Volcán Chillán), which was the main active vent during the 17th-19th centuries, occupies the SE end. The Volcán Nuevo lava-dome complex formed during 1906-1945 on the NW flank of Viejo. The Volcán Arrau dome complex was then constructed on the SE side of Volcán Nuevo between 1973 and 1986, and eventually exceeded its height. Smaller domes or cones are present in the 5-km valley between the two major edifices. Sources: Servicio Nacional de GeologÃa y MinerÃa (SERNAGEOMIN) https://urldefense.com/v3/__http://www.sernageomin.cl/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKf4nV2hw$ <https://urldefense.com/v3/__http://www.sernageomin.cl/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFsHWNkPg$> ; Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI) https://urldefense.com/v3/__http://www.onemi.cl/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKVj8XW7i$ <https://urldefense.com/v3/__http://www.onemi.cl/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wF2nhWbtE$> Pavlof | Alaska Peninsula, Alaska | 55.417°N, 161.894°W | Summit elev. 2493 m AVO reported that the eruption at a vent on Pavlofâ??s upper E flank was ongoing during 17-24 May, and seismic tremor persisted. Daily elevated surface temperatures were identified in satellite images consistent with the effusion of short lava flows on the upper flank. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. Geologic Summary. The most active volcano of the Aleutian arc, Pavlof is a 2519-m-high Holocene stratovolcano that was constructed along a line of vents extending NE from the Emmons Lake caldera. Pavlof and its twin volcano to the NE, 2142-m-high Pavlof Sister, form a dramatic pair of symmetrical, glacier-covered stratovolcanoes that tower above Pavlof and Volcano bays. A third cone, Little Pavlof, is a smaller volcano on the SW flank of Pavlof volcano, near the rim of Emmons Lake caldera. Unlike Pavlof Sister, Pavlof has been frequently active in historical time, typically producing Strombolian to Vulcanian explosive eruptions from the summit vents and occasional lava flows. The active vents lie near the summit on the north and east sides. The largest historical eruption took place in 1911, at the end of a 5-year-long eruptive episode, when a fissure opened on the N flank, ejecting large blocks and issuing lava flows. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKRDCJmPL$ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFeGfIzX0$> Rincon de la Vieja | Costa Rica | 10.83°N, 85.324°W | Summit elev. 1916 m OVSICORI-UNA reported that a few small phreatic explosions at Rincón de la Vieja were recorded during the previous week. A phreatic explosion at 1343 on 18 May produced a steam-and-gas plume that rose 200 m above the crater rim. At 1710 on 19 May an eruptive event produced a gas-and-steam plume that rose 100 m above the summit. More small eruptive events at 0251 and 0443 on 21 May were recorded by seismic and infrasound instruments. Geologic Summary. Rincón de la Vieja, the largest volcano in NW Costa Rica, is a remote volcanic complex in the Guanacaste Range. The volcano consists of an elongated, arcuate NW-SE-trending ridge constructed within the 15-km-wide early Pleistocene GuachipelÃn caldera, whose rim is exposed on the south side. Sometimes known as the "Colossus of Guanacaste," it has an estimated volume of 130 km3 and contains at least nine major eruptive centers. Activity has migrated to the SE, where the youngest-looking craters are located. The twin cone of Santa MarÃa volcano, the highest peak of the complex, is located at the eastern end of a smaller, 5-km-wide caldera and has a 500-m-wide crater. A Plinian eruption producing the 0.25 km3 RÃo Blanca tephra about 3,500 years ago was the last major magmatic eruption. All subsequent eruptions, including numerous historical eruptions possibly dating back to the 16th century, have been from the prominent active crater containing a 500-m-wide acid lake located ENE of Von Seebach crater. Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA) https://urldefense.com/v3/__http://www.ovsicori.una.ac.cr/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKZPQZtRW$ <https://urldefense.com/v3/__http://www.ovsicori.una.ac.cr/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wF-sAwPq4$> Ruapehu | North Island (New Zealand) | 39.28°S, 175.57°E | Summit elev. 2797 m On 24 May GeoNet reported that elevated unrest at Ruapehu continued, though at reduced levels. During the previous week the levels of volcanic tremor further declined, were variable, but remained above normal. The lake water temperature decreased from a peak of 41 degrees Celsius on 8 May to 30 degrees Celsius, showing a cooling trend. A gas measurement flight on 13 May confirmed continuing high levels of gas emissions, though at values lower than measured two weeks prior; sulfur dioxide and carbon dioxide flux rates were at 179 and 1,658 tonnes per day, respectively; data from new instruments confirmed that these levels remained elevated. The Volcanic Alert Level remained at 2 (on a scale from 0-5) and the Aviation Color Code remained at Yellow. Geologic Summary. Ruapehu, one of New Zealand's most active volcanoes, is a complex stratovolcano constructed during at least four cone-building episodes dating back to about 200,000 years ago. The dominantly andesitic 110 km3 volcanic massif is elongated in a NNE-SSW direction and surrounded by another 100 km3 ring plain of volcaniclastic debris, including the NW-flank Murimoto debris-avalanche deposit. A series of subplinian eruptions took place between about 22,600 and 10,000 years ago, but pyroclastic flows have been infrequent. The broad summait area and flank contain at least six vents active during the Holocene. Frequent mild-to-moderate explosive eruptions have been recorded from the Te Wai a-Moe (Crater Lake) vent, and tephra characteristics suggest that the crater lake may have formed as recently as 3,000 years ago. Lahars resulting from phreatic eruptions at the summit crater lake are a hazard to a ski area on the upper flanks and lower river valleys. Source: GeoNet https://urldefense.com/v3/__http://www.geonet.org.nz/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKZW8UTok$ <https://urldefense.com/v3/__http://www.geonet.org.nz/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFIb0FrHQ$> Semeru | Eastern Java | 8.108°S, 112.922°E | Summit elev. 3657 m PVMBG reported that the eruption at Semeru continued during 17-24 May. White plumes were occasionally visible rising 100-700 m above the summit. Several eruptive events (recorded at 0525 on 19 May, at 0552 on 20 May, at 0525 on 21 May, at 0632 on 22 May, and at 0624 on 23 May) produced ash plumes that rose 200-500 m above the summit and drifted S and SW. The Alert Level remained at 3 (on a scale of 1-4). The public was warned to stay at least 5 km away from the summit, and 500 m away from Kobokan drainages within 17 km of the summit, and along with other drainages originating on Semeru, including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards. Geologic Summary. Semeru, the highest volcano on Java, and one of its most active, lies at the southern end of a volcanic massif extending north to the Tengger caldera. The steep-sided volcano, also referred to as Mahameru (Great Mountain), rises above coastal plains to the south. Gunung Semeru was constructed south of the overlapping Ajek-ajek and Jambangan calderas. A line of lake-filled maars was constructed along a N-S trend cutting through the summit, and cinder cones and lava domes occupy the eastern and NE flanks. Summit topography is complicated by the shifting of craters from NW to SE. Frequent 19th and 20th century eruptions were dominated by small-to-moderate explosions from the summit crater, with occasional lava flows and larger explosive eruptions accompanied by pyroclastic flows that have reached the lower flanks of the volcano. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKdE2f3eY$ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFLTI-t4Y$> Semisopochnoi | Aleutian Islands (USA) | 51.93°N, 179.58°E | Summit elev. 1221 m AVO reported that low-level eruptive activity at Semisopochnoi's North Cerberus cone continued during 17-24 May. Seismicity continued to be elevated with intermittent tremor and several daily explosions recorded by infrasound and seismic instruments. Low-level ash emissions were visible in clear satellite images and webcam views; clouds sometimes obscured views towards the end of the week. A sulfur dioxide plume drifted 240 km N during 17-18 May, and sulfur dioxide emissions were detected during 23-24 May. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch. Geologic Summary. Semisopochnoi, the largest subaerial volcano of the western Aleutians, is 20 km wide at sea level and contains an 8-km-wide caldera. It formed as a result of collapse of a low-angle, dominantly basaltic volcano following the eruption of a large volume of dacitic pumice. The high point of the island is Anvil Peak, a double-peaked late-Pleistocene cone that forms much of the island's northern part. The three-peaked Mount Cerberus was constructed within the caldera during the Holocene. Each of the peaks contains a summit crater; lava flows on the N flank of Cerberus appear younger than those on the south side. Other post-caldera volcanoes include the symmetrical Sugarloaf Peak SSE of the caldera and Lakeshore Cone, a small cinder cone at the edge of Fenner Lake in the NE part of the caldera. Most documented eruptions have originated from Cerberus, although Coats (1950) considered that both Sugarloaf and Lakeshore Cone could have been recently active. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKRDCJmPL$ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFeGfIzX0$> Sheveluch | Central Kamchatka (Russia) | 56.653°N, 161.36°E | Summit elev. 3283 m KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 13-20 May, and lava-dome extrusion continued. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted. Geologic Summary. The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1300 km3 volcano is one of Kamchatka's largest and most active volcanic structures. The summit of roughly 65,000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera breached to the south. Many lava domes dot its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large horseshoe-shaped caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. At least 60 large eruptions have occurred during the Holocene, making it the most vigorous andesitic volcano of the Kuril-Kamchatka arc. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka. Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKapqUoMl$ <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wFOBNbD9E$> Suwanosejima | Ryukyu Islands (Japan) | 29.638°N, 129.714°E | Summit elev. 796 m JMA reported that eruptive activity continued to be recorded at Suwanosejima's Ontake Crater during 16-23 May. Eruption plumes rose as high as 1.9 km above the crater rim and material was ejected 400 m above the vent. Ash fell in Toshima village (3.5 km SSW) and in other areas within 5 km. Three explosions were recorded during 20-23 May and crater incandescence from the crater was visible at night. The Alert Level remained at 3 and the public was warned to stay 2 km away from the crater. Geologic Summary. The 8-km-long, spindle-shaped island of Suwanosejima in the northern Ryukyu Islands consists of an andesitic stratovolcano with two historically active summit craters. The summit is truncated by a large breached crater extending to the sea on the east flank that was formed by edifice collapse. Suwanosejima, one of Japan's most frequently active volcanoes, was in a state of intermittent strombolian activity from Otake, the NE summit crater, that began in 1949 and lasted until 1996, after which periods of inactivity lengthened. The largest historical eruption took place in 1813-14, when thick scoria deposits blanketed residential areas, and the SW crater produced two lava flows that reached the western coast. At the end of the eruption the summit of Otake collapsed forming a large debris avalanche and creating the horseshoe-shaped Sakuchi caldera, which extends to the eastern coast. The island remained uninhabited for about 70 years after the 1813-1814 eruption. Lava flows reached the eastern coast of the island in 1884. Only about 50 people live on the island. Source: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!ZnY3WGoRq0f4LCbWQ6W-uAPpfrhqMki5MlWDW8R87axH74wjWobxwjS68dmZtvsJ8LLg88FIKXKK3DpI$ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!fjM6X-wYWBW--Bp1DldYNI4qxYnI_PU7ar8cm29flv07dRfVx933m40ZldfCy4RRB3wF-u7uzcM$> 4-4-4-4-4-4-4-4-4-4-4-4-4 ============================================================== 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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