3-3-3-3-3-3-3-3-3-3-3-3-3 From: "Kuhn, Sally" <KUHNS@xxxxxx> Smithsonian / USGS Weekly Volcanic Activity Report 28 August-3 September 2024 Sally Sennert - Weekly Report Editor (kuhns@xxxxxx) URL: https://volcano.si.edu/reports_weekly.cfm <https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGXvU1iOrA$> New Activity/Unrest: Karymsky, Eastern Kamchatka (Russia) | Kikai, Ryukyu Islands (Japan) | Klyuchevskoy, Central Kamchatka (Russia) | 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 | Lewotobi, Flores Island | Marapi, Central Sumatra | Merapi, Central Java | Nyamulagira, DR Congo | Semeru, Eastern Java | Shishaldin, Fox Islands (USA) | Stromboli, Aeolian Islands (Italy) | Suwanosejima, Ryukyu Islands (Japan) | Yasur, Vanuatu 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 Karymsky | Eastern Kamchatka (Russia) | 54.049°N, 159.443°E | Summit elev. 1513 m KVERT reported moderate levels of activity at Karymsky during 22-29 August. A weak thermal anomaly over the volcano was identified in satellite images during 26 and 28-29 August; weather clouds obscured views on the other days during the week. A series of six significant explosions beginning at 0810 on 30 August generated ash plumes that rose as high as 10 km (32,800 ft) a.s.l. and drifted NW, SE, and ENE. The Aviation Color Code was raised to Red (the highest level on a four-color scale). Pilots observed ash plumes rising 6-7 km (19,700-23,000 ft) a.s.l. and drifting ENE. At 0923 the Aviation Color Code was lowered to Orange. 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!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGWZJkPu9w$> Kikai | Ryukyu Islands (Japan) | 30.793°N, 130.305°E | Summit elev. 704 m JMA reported that an eruptive event at Iodake Crater located at Satsuma Iwo-jima, a subaerial part of Kikaiâ??s NW caldera rim, was recorded at 1128 on 1 September. An ash plume rose 1 km above the crater rim. The report noted that there was no change in the number of earthquakes either before or after the event, and no volcanic tremors were recorded. An eruptive event at 1008 on 3 September generated a volcanic plume that rose 700 m above the crater rim. Crater incandescence continued to be observed at night. The 1 September event was the first eruptive activity since 6 October 2020. The Alert Level remained at 2 (on a 5-level scale), and residents were warned to stay 500 m away from Iodake Crater. Geologic Summary. Multiple eruption centers have exhibited recent activity at Kikai, a mostly submerged, 19-km-wide caldera near the northern end of the Ryukyu Islands south of Kyushu. It was the source of one of the world's largest Holocene eruptions about 6,300 years ago when rhyolitic pyroclastic flows traveled across the sea for a total distance of 100 km to southern Kyushu, and ashfall reached the northern Japanese island of Hokkaido. The eruption devastated southern and central Kyushu, which remained uninhabited for several centuries. Post-caldera eruptions formed Iodake (or Iwo-dake) lava dome and Inamuradake scoria cone, as well as submarine lava domes. Recorded eruptions have occurred at or near Satsuma-Iojima (also known as Tokara-Iojima), a small 3 x 6 km island forming part of the NW caldera rim. Showa-Iojima lava dome (also known as Iojima-Shinto), a small island 2 km E of Satsuma-Iojima, was formed during submarine eruptions in 1934 and 1935. Mild-to-moderate explosive eruptions have occurred during the past few decades from Iodake, a rhyolitic lava dome at the eastern end of Satsuma-Iojima. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGVcWufSoQ$> Klyuchevskoy | Central Kamchatka (Russia) | 56.056°N, 160.642°E | Summit elev. 4754 m A sudden increase in seismicity at Klyuchevskoy during 1-3 September prompted KVERT to raise the Aviation Color Code to Yellow (the second lowest level on a four-color scale) at 0822 on 4 September. Dates and times are in UTC; specific events are in local time where noted. Geologic Summary. Klyuchevskoy is the highest and most active volcano on the Kamchatka Peninsula. Since its origin about 6,000 years ago, this symmetrical, basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. It rises above a saddle NE of Kamen volcano and lies SE of the broad Ushkovsky massif. More than 100 flank eruptions have occurred during approximately the past 3,000 years, with most lateral craters and cones occurring along radial fissures between the unconfined NE-to-SE flanks of the conical volcano between 500 and 3,600 m elevation. Eruptions recorded since the late 17th century have resulted in frequent changes to the morphology of the 700-m-wide summit crater. These eruptions over the past 400 years have originated primarily from the summit crater, but have also included numerous major explosive and effusive eruptions from flank craters. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGWZJkPu9w$> Reykjanes | Reykjanes Peninsula | 63.817°N, 22.717°W | Summit elev. 140 m IMO reported that the eruption between Stóra-Skógfell and Sundhnúkur, within the Reykanes volcanic system, continued at the N end of the fissure during 27 August-3 September. By 29 August vigorous lava fountaining was concentrated at two main vents, though over the rest of the week the intensity of the eruption decreased. Lava slowly flowed mainly NW and to a lesser extent to the E. Subsidence was detected during the first part of the week; no deformation recorded during the second half of the week, suggesting that the rate of magma accumulation area under Svartsengi was similar to the rate of surface lava effusion. Plumes of sulfur dioxide gas from the eruption and smoke from vegetation fires started by lava caused significant pollution in areas downwind. According to Almannavarnadeild rÃkislögreglustjóra, notable levels of sulfur dioxide gas concentrations (1,000 micrograms per cubic meter) were measured in Vogar on Vatnsleysustrand along the N coast on 30 August. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). 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!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGWWclUn4A$> ; Almannavarnadeild rÃkislögreglustjóra (National Commissioner of the Icelandic Police and Department of Civil Protection and Emergency Management) https://www.almannavarnir.is/ <https://urldefense.com/v3/__https://www.almannavarnir.is/__;!!IKRxdwAv5BmarQ!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGUQRHSKFQ$> Sheveluch | Central Kamchatka (Russia) | 56.653°N, 161.36°E | Summit elev. 3283 m KVERT reported that during 22 August-1 September lava extrusion likely 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. Thermal anomalies over the domes were identified in satellite images during 23, 26-27, and 29 August. Resuspended ash drifted 570 km SE during 28-29 August based on satellite images. Strong explosions at 1115 on 1 September generated ash plumes that rose as high as 8 km (26,200 ft) a.s.l. and drifted NE. By 2130 the ash cloud was about 340 km long and the leading E edge of the plume was about 770 km from the volcano. Explosive activity continued during 1-2 September. On 2 September ash plumes rose 3.5-4.5 km (11,500-14,800 ft) a.s.l. 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!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGWZJkPu9w$> Whakaari/White Island | North Island (New Zealand) | 37.52°S, 177.18°E | Summit elev. 294 m The Wellington VAAC reported ongoing low-level, continuous emissions from Whakaari/White Island during 28 August-3 September based on satellite data, pilot observations, webcam views, and weather models. The plumes rose 0.9-1.5 km (3,000-5,000 ft) a.s.l. and drifted E and SE, though during the first part of the week they were often obscured by weather clouds. On 2 September ash plumes were visible above the weather clouds and ash was present in the plumes at multiple altitudes. Geologic Summary. The uninhabited Whakaari/White Island is the 2 x 2.4 km emergent summit of a 16 x 18 km submarine volcano in the Bay of Plenty about 50 km offshore of North Island. The island consists of two overlapping andesitic-to-dacitic stratovolcanoes. The SE side of the crater is open at sea level, with the recent activity centered about 1 km from the shore close to the rear crater wall. Volckner Rocks, sea stacks that are remnants of a lava dome, lie 5 km NW. Descriptions of volcanism since 1826 have included intermittent moderate phreatic, phreatomagmatic, and Strombolian eruptions; activity there also forms a prominent part of Maori legends. The formation of many new vents during the 19th and 20th centuries caused rapid changes in crater floor topography. Collapse of the crater wall in 1914 produced a debris avalanche that buried buildings and workers at a sulfur-mining project. Explosive activity in December 2019 took place while tourists were present, resulting in many fatalities. The official government name Whakaari/White Island is a combination of the full Maori name of Te Puia o Whakaari ("The Dramatic Volcano") and White Island (referencing the constant steam plume) given by Captain James Cook in 1769. Source: Wellington Volcanic Ash Advisory Center (VAAC) http://vaac.metservice.com/ <https://urldefense.com/v3/__http://vaac.metservice.com/__;!!IKRxdwAv5BmarQ!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGX1dpxorw$> 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 26 August-2 September. Nighttime crater incandescence was visible in webcam images on most days during dark hours, though weather clouds prevented views during 28-30 August. During a field visit on 27 August sulfur dioxide emissions averaged 1,500 tons per day, slightly higher than the average value. At 1358 on 1 September an ash plume rose as high as 1.2 km above the crater rim and drifted N. Emissions were continuous until 1510 that same day, generating ash plumes that rose 1 km above the crater rim and drifted N. 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!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGVcWufSoQ$> Dukono | Halmahera | 1.6992°N, 127.8783°E | Summit elev. 1273 m PVMBG reported that the eruption at Dukono was ongoing during 28 August-3 September. Gray-and-white ash plumes that were sometimes dense rose 100-900 m above the summit and drifted E, NE, and W on most days; white plumes rose as high as 1 km above the summit and drifted E and NW on 29 August and 2 September. The Alert Level remained at Level 2 (on a scale of 1-4), and the public was warned to remain outside of the 3-km exclusion zone. Geologic Summary. Reports from this remote volcano in northernmost Halmahera are rare, but Dukono has been one of Indonesia's most active volcanoes. More-or-less continuous explosive eruptions, sometimes accompanied by lava flows, have occurred since 1933. During a major eruption in 1550 CE, a lava flow filled in the strait between Halmahera and the N-flank Gunung Mamuya cone. This complex volcano presents a broad, low profile with multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of the summit crater complex, contains a 700 x 570 m crater that has also been active during historical time. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGXGUTdIyQ$> 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 22-29 August. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E), explosions during 22 and 26-28 August generated ash plumes that rose as high as 2 km (6,600 ft) a.s.l. and drifted SE, NE, and NW. Satellite data indicated that either no activity was observed, or weather conditions prevented views. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates are UTC; specific events are in local time where noted. Geologic Summary. The flat-topped summit of the central cone of Ebeko volcano, one of the most active in the Kuril Islands, occupies the northern end of Paramushir Island. Three summit craters located along a SSW-NNE line form Ebeko volcano proper, at the northern end of a complex of five volcanic cones. Blocky lava flows extend west from Ebeko and SE from the neighboring Nezametnyi cone. The eastern part of the southern crater contains strong solfataras and a large boiling spring. The central crater is filled by a lake about 20 m deep whose shores are lined with steaming solfataras; the northern crater lies across a narrow, low barrier from the central crater and contains a small, cold crescentic lake. Historical activity, recorded since the late-18th century, has been restricted to small-to-moderate explosive eruptions from the summit craters. Intense fumarolic activity occurs in the summit craters, on the outer flanks of the cone, and in lateral explosion craters. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGWZJkPu9w$> Great Sitkin | Andreanof Islands (USA) | 52.076°N, 176.13°W | Summit elev. 1740 m AVO reported that slow lava effusion continued to feed a thick lava flow in Great Sitkinâ??s summit crater during 27 August-3 September. Seismicity was low with few small daily earthquakes. A satellite image on 29 August indicated that the flow advanced NE. Weakly elevated surface temperatures were detected in satellite data on 31 August. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale). Geologic Summary. The Great Sitkin volcano forms much of the northern side of Great Sitkin Island. A younger volcano capped by a small, 0.8 x 1.2 km ice-filled summit caldera was constructed within a large late-Pleistocene or early Holocene scarp formed by massive edifice failure that truncated an older edifice and produced a submarine debris avalanche. Deposits from this and an even older debris avalanche from a source to the south cover a broad area of the ocean floor north of the volcano. The summit lies along the eastern rim of the younger collapse scarp. Deposits from an earlier caldera-forming eruption of unknown age cover the flanks of the island to a depth up to 6 m. The small younger caldera was partially filled by lava domes emplaced in 1945 and 1974, and five small older flank lava domes, two of which lie on the coastline, were constructed along northwest- and NNW-trending lines. Hot springs, mud pots, and fumaroles occur near the head of Big Fox Creek, south of the volcano. Eruptions have been recorded since the late-19th century. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://avo.alaska.edu/ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGXzt6w1Hg$> Ibu | Halmahera | 1.488°N, 127.63°E | Summit elev. 1325 m PVMBG reported that activity at Ibu continued during 28 August-3 September with multiple eruptive events recorded daily. Daily gray or white-and-gray ash plumes that were sometimes dense generally rose as high as 1.5 km above the summit and drifted in multiple directions. Some webcam images posted with the reports showed incandescence visible above the crater rim. 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!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGXGUTdIyQ$> Kanlaon | Philippines | 10.4096°N, 123.13°E | Summit elev. 2422 m PHIVOLCS reported that unrest at Kanlaon continued during 27 August-3 September. There were 3-12 daily volcanic earthquakes recorded by the seismic network. Steam-and-gas emissions rose 100-500 m above the summit and drifted ENE, E, SW, and W on most days. Sulfur dioxide emissions declined during the week, averaging 4,585 (27 August), 4,418 (28 August), 3,189 (29 August), and 2,669 (31 August) tonnes per day. The Alert Level remained at 2 (on a scale of 0-5) and PHIVOLCS reminded the public to remain outside of the 4-km-radius Permanent Danger Zone. Geologic Summary. Kanlaon volcano (also spelled Canlaon) forms the highest point on the Philippine island of Negros. The massive andesitic stratovolcano is covered with fissure-controlled pyroclastic cones and craters, many of which are filled by lakes. The largest debris avalanche known in the Philippines traveled 33 km SW from Kanlaon. The summit contains a 2-km-wide, elongated northern caldera with a crater lake and a smaller but higher active vent, Lugud crater, to the south. Eruptions recorded since 1866 have typically consisted of phreatic explosions of small-to-moderate size that produce minor local ashfall. Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS) http://www.phivolcs.dost.gov.ph/ <https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGVvT9vG0w$> 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 28 August-3 September. Daily gray or white-and-gray ash plumes that were sometimes dense rose as high as 1 km above the summit and drifted mainly SW, W, and NW; plumes drifted N and NE on 31 August. The Alert Level remained at 3 (the second highest level on a scale of 1-4) and the public was warned to stay outside of the exclusion zone, defined as a 3 km radius around both Laki-laki and Perempuan craters, 4 km to the NNW and SSE of Laki-laki. Geologic Summary. The Lewotobi edifice in eastern Flores Island is composed of the two adjacent Lewotobi Laki-laki and Lewotobi Perempuan stratovolcanoes (the "husband and wife"). Their summits are less than 2 km apart along a NW-SE line. The conical Laki-laki to the NW has been frequently active during the 19th and 20th centuries, while the taller and broader Perempuan has had observed eruptions in 1921 and 1935. Small lava domes have grown during the 20th century in both of the summit craters, which are open to the north. A prominent cone, Iliwokar, occurs on the E flank of Perampuan. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGXGUTdIyQ$> Marapi | Central Sumatra | 0.38°S, 100.474°E | Summit elev. 2885 m PVMBG reported that eruptive activity at Marapi (on Sumatra) was ongoing during 28 August-3 September. On 30 August and 3 September white emissions rose 200-300 m above the summit and drifted N, E, and SE. At 0823 on 31 August a dense white-and-gray ash plume rose 400 m above the summit and drifted N. Emissions were not reported on the other days of the week. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to stay 3 km away from the active crater. Geologic Summary. Gunung Marapi, not to be confused with the better-known Merapi volcano on Java, is Sumatra's most active volcano. This massive complex stratovolcano rises 2,000 m above the Bukittinggi Plain in the Padang Highlands. A broad summit contains multiple partially overlapping summit craters constructed within the small 1.4-km-wide Bancah caldera. The summit craters are located along an ENE-WSW line, with volcanism migrating to the west. More than 50 eruptions, typically consisting of small-to-moderate explosive activity, have been recorded since the end of the 18th century; no lava flows outside the summit craters have been reported in historical time. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGXGUTdIyQ$> Merapi | Central Java | 7.54°S, 110.446°E | Summit elev. 2910 m BPPTKG reported that the eruption at Merapi (on Java) continued during 23-29 August. Earthquakes were less intense compared to the previous week. The SW lava dome produced lava avalanches that descended the S and SW flanks; 327 traveled as far as 2 km SW down the upper part of the Sat/Putih drainage and two traveled as far as 1.3 km S down the Boyong drainage. Eight pyroclastic flows descended the Bebeng drainage as far as 1.5 km. Morphological changes to the SW lava dome were due to continuing effusion and collapses of material. The hottest temperature was around 243 degrees Celsius on 25 August, 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!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGXr7Mr8fg$> Nyamulagira | DR Congo | 1.408°S, 29.2°E | Summit elev. 3058 m In a 3 September satellite image of Nyamuragira part of the end of the lava flow on the WNW flank was visible through weather clouds in a small area about 5.8 km from the center of the caldera. The lava was incandescent, suggesting continued activity. Part of the flow on the NNW flank was visible through the clouds in an area about 3.6 km from the center of the caldera, but it appeared black and was likely cooling. Geologic Summary. Africa's most active volcano, Nyamulagira (also known as Nyamuragira), is a massive high-potassium basaltic shield about 25 km N of Lake Kivu and 13 km NNW of the steep-sided Nyiragongo volcano. The summit is truncated by a small 2 x 2.3 km caldera that has walls up to about 100 m high. Documented eruptions have occurred within the summit caldera, as well as from the numerous flank fissures and cinder cones. A lava lake in the summit crater, active since at least 1921, drained in 1938, at the time of a major flank eruption. Recent lava flows extend down the flanks more than 30 km from the summit as far as Lake Kivu; extensive lava flows from this volcano have covered 1,500 km2 of the western branch of the East African Rift. Source: Copernicus https://www.copernicus.eu/en <https://urldefense.com/v3/__https://www.copernicus.eu/en__;!!IKRxdwAv5BmarQ!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGVpIn_YYQ$> Semeru | Eastern Java | 8.108°S, 112.922°E | Summit elev. 3657 m PVMBG reported that eruptive activity continued at Semeru during 28 August-3 September with multiple daily eruptive events recorded by the seismic network. White-and-gray or gray ash plumes that were sometimes dense rose 200-1,000 m above the summit and drifted in multiple directions on most days; weather conditions sometimes prevented visual confirmation of the eruptive events, especially on 1 and 3 September. Crater incandescence was sometimes visible in webcam images. 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!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGXGUTdIyQ$> Shishaldin | Fox Islands (USA) | 54.756°N, 163.97°W | Summit elev. 2857 m AVO reported that volcanic unrest at Shishaldin declined over the past several months. Slightly elevated seismicity, small infrasound signals, and weak gas emissions persisted, but there were no signs of explosivity nor the presence of lava in the summit crater. AVO noted that the activity was at background levels, and at 0900 on 30 August the Volcano Alert Level was lowered to Normal (the lowest level on a four-level scale) and the Aviation Color Code was lowered to Green (the lowest color on a four-color scale). Geologic Summary. The symmetrical glacier-covered Shishaldin in the Aleutian Islands is the westernmost of three large stratovolcanoes in the eastern half of Unimak Island. The Aleuts named the volcano Sisquk, meaning "mountain which points the way when I am lost." Constructed atop an older glacially dissected edifice, it is largely basaltic in composition. Remnants of an older edifice are exposed on the W and NE sides at 1,500-1,800 m elevation. There are over two dozen pyroclastic cones on its NW flank, which is covered by massive aa lava flows. Frequent explosive activity, primarily consisting of Strombolian ash eruptions from the small summit crater, but sometimes producing lava flows, has been recorded since the 18th century. A steam plume often rises from the summit crater. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://avo.alaska.edu/ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGXzt6w1Hg$> Stromboli | Aeolian Islands (Italy) | 38.789°N, 15.213°E | Summit elev. 924 m INGV reported that eruptive activity continued at Stromboli during 26 August-1 September. 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 continued to produce explosions at a rate of 8-14 events per hour, ejecting lapilli and bombs 80-150 m above the vents. The third and southernmost vent ejected spatter more continuously and intensely compared to the previous week. Medium-intensity explosions at the vent in Area C-S ejected tephra over 250 m above the vent at a rate of 1-4 events per hour. Following a period of intense spattering from a vent in Area N, a lava flow was visible at 0244 on 30 August quickly descending the Sciara del Fuoco; the lava supply had decreased by 0700. Intense spattering at the N vent in Area N was observed at 1232 and was followed by a second lava flow. The effusion rate was the highest in the early afternoon and by 2300 the supply was minimal. A third lava flow began at 0430 on 31 August and descended the Sciara del Fuoco, overlapping the previous flows. By 1000 the flow was not well fed and cooling. The lava flows were confined to the drainage along the Sciara del Fuoco, and only small amounts of lava reached the coastline. The Alert Level remained at Yellow (the second lowest level on a four-level scale). Geologic Summary. Spectacular incandescent nighttime explosions at Stromboli have long attracted visitors to the "Lighthouse of the Mediterranean" in the NE Aeolian Islands. This volcano has lent its name to the frequent mild explosive activity that has characterized its eruptions throughout much of historical time. The small island is the emergent summit of a volcano that grew in two main eruptive cycles, the last of which formed the western portion of the island. The Neostromboli eruptive period took place between about 13,000 and 5,000 years ago. The active summit vents are located at the head of the Sciara del Fuoco, a prominent scarp that formed about 5,000 years ago due to a series of slope failures which extends to below sea level. The modern volcano has been constructed within this scarp, which funnels pyroclastic ejecta and lava flows to the NW. Essentially continuous mild Strombolian explosions, sometimes accompanied by lava flows, have been recorded for more than a millennium. Sources: Sezione di Catania - Osservatorio Etneo (INGV) http://www.ct.ingv.it/ <https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGXpfaWGcQ$> ; Dipartimento della Protezione Civile https://www.protezionecivile.gov.it/it/ <https://urldefense.com/v3/__https://www.protezionecivile.gov.it/it/__;!!IKRxdwAv5BmarQ!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGW1nInHNw$> 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 26 August-2 September. Crater incandescence was observed nightly in webcam images. An explosion at 0056 on 1 September generated an ash plume that rose 1 km above the crater rim and drifted SE. Eruptive events at 0813 and 0917 on 1 September and at 0338 and 0416 on 2 September generated ash plumes that rose 1-1.1 km above the crater rim and drifted SE and N. Rumbling was heard at the Suwanosejima Branch Office in Toshima village (3.5 km SSW) on an unspecified date. 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!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGVcWufSoQ$> Yasur | Vanuatu | 19.532°S, 169.447°E | Summit elev. 361 m On 29 August the Vanuatu Meteorology and Geohazards Department (VMGD) reported that activity at Yasur continued at a level of â??major unrest,â?? as defined by the Alert Level 2 status (on a scale of 0-5). Recent visual observations, webcam mages, and photos taken in the field indicated that explosions continued, producing emissions of gas, steam, and/or ash. Gas emissions and thermal anomalies were identified in satellite images. The report warned that some of the explosions may eject material that falls in and around the crater. The public was reminded to not enter the restricted area within 600 m around the boundaries of the Permanent Exclusion Zone, defined by Danger Zone A on the hazard map. Geologic Summary. Yasur has exhibited essentially continuous Strombolian and Vulcanian activity at least since Captain Cook observed ash eruptions in 1774. This style of activity may have continued for the past 800 years. Located at the SE tip of Tanna Island in Vanuatu, this pyroclastic cone has a nearly circular, 400-m-wide summit crater. The active cone is largely contained within the small Yenkahe caldera, and is the youngest of a group of Holocene volcanic centers constructed over the down-dropped NE flank of the Pleistocene Tukosmeru volcano. The Yenkahe horst is located within the Siwi ring fracture, a 4-km-wide open feature associated with eruption of the andesitic Siwi pyroclastic sequence. Active tectonism along the Yenkahe horst accompanying eruptions has raised Port Resolution harbor more than 20 m during the past century. Source: Vanuatu Meteorology and Geohazards Department (VMGD) http://www.geohazards.gov.vu/ <https://urldefense.com/v3/__http://www.geohazards.gov.vu/__;!!IKRxdwAv5BmarQ!bRRlUIUl8AOCtQMJeUsGGySv-GBZXFwSev7o10iECIo4E8nUh7676R0FJ5olp2eA_hOJPirWFKwuI4NduGUhzRiACg$> 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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