7-7-7-7-7-7-7-7-7-7-7-7-7-7 From: "Kuhn, Sally" <KUHNS@xxxxxx> Smithsonian / USGS Weekly Volcanic Activity Report 7-13 August 2024 Sally Sennert - Weekly Report Editor (kuhns@xxxxxx) URL: https://volcano.si.edu/reports_weekly.cfm <https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV9vL2vaOQ$> New Activity/Unrest: Bezymianny, Central Kamchatka (Russia) | Whakaari/White Island, North Island (New Zealand) Ongoing Activity: Aira, Kyushu (Japan) | Dempo, Southeastern Sumatra | Dukono, Halmahera | Ebeko, Paramushir Island (Russia) | Great Sitkin, Andreanof Islands (USA) | Ibu, Halmahera | Ijen, Eastern Java | Kanlaon, Philippines | Karangetang, Sangihe Islands | Karymsky, Eastern Kamchatka (Russia) | Lewotobi, Flores Island | Merapi, Central Java | Rincon de la Vieja, Costa Rica | Sabancaya, Peru | Semeru, Eastern Java | Sheveluch, Central Kamchatka (Russia) | Suwanosejima, Ryukyu Islands (Japan) | Taal, Luzon (Philippines) 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 KVERT reported that a daily thermal anomaly over Bezymianny was identified in satellite images during 1-8 August. Plumes of resuspended ash drifted 90 km SE during 3-4 August. Dates are based on UTC times; specific events are in local time where noted. Geologic Summary. The modern Bezymianny, much smaller than its massive neighbors Kamen and Kliuchevskoi on the Kamchatka Peninsula, was formed about 4,700 years ago over a late-Pleistocene lava-dome complex and an edifice built about 11,000-7,000 years ago. Three periods of intensified activity have occurred during the past 3,000 years. The latest period, which was preceded by a 1,000-year quiescence, began with the dramatic 1955-56 eruption. This eruption, similar to that of St. Helens in 1980, produced a large open crater that was formed by collapse of the summit and an associated lateral blast. Subsequent episodic but ongoing lava-dome growth, accompanied by intermittent explosive activity and pyroclastic flows, has largely filled the 1956 crater. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV9RYGTZ-A$> Whakaari/White Island | North Island (New Zealand) | 37.52°S, 177.18°E | Summit elev. 294 m GeoNet reported that a vigorous volcanic plume at Whakaari/White Island was identified in satellite and webcam images on 9 August with the most active period occurring during 1300-1500. The plume drifted E and contained a minor amount of ash, prompting GeoNet to raise the Volcanic Alert Level to 3 (on a scale of 0-5) and the Aviation Color Code to Orange (the second highest level on a four-color scale). Activity diminished later that day. Emissions with low ash content began around 0000 on 11 August that drifted W and were continuous at least through 1015. The ash plume rose to 1-2 km a.s.l. and a steam plume rose to around 2 km a.s.l. Sulfur dioxide emissions were identified in satellite data for the first time during the current active period, which began in May. The satellite instrument is less sensitive than instruments used during gas observations flights, suggesting that sulfur dioxide emissions had increased. Low-level plumes containing minor amounts of ash continued to be identified in satellite images and images from webcams located in Whakatane and Te Kaha during 12-14 August. Weather occasionally prevented visual observations. GeoNet noted that sulfur dioxide emissions coupled with minor eruptive activity suggested that magma had ascended to shallow levels. 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: GeoNet http://www.geonet.org.nz/ <https://urldefense.com/v3/__http://www.geonet.org.nz/__;!!IKRxdwAv5BmarQ!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV9Lvoaf7w$> 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) characterized as explosions and eruptive events during 5-12 August. Nighttime crater incandescence was visible in webcam images. An explosion at 0037 on 6 August produced an ash plume that rose 3 km above the crater rim and drifted SW and ejected large blocks 1.3-1.7 km from the crater rim. A large amount of ash fell in Kagoshima City (about 10 km W) within an hour after the explosion. An explosion at 2137 generated an ash plume that rose 800 m above the crater rim before merging into weather clouds and ejected large blocks 800-1,100 m from the crater rim. An ash plume from an explosion at 1444 on 7 August rose 2.3 km above the crater rim and drifted S. Eruptive events at 0329 on 6 August, 1207 on 7 August, 2308 on 8 August, 1913 and 2239 on 9 August, and 0541 on 12 August produced ash plumes that rose 1.1-1.7 km above the crater rim and rose above the crater or drifted S and SE. 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!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV9ZxpTdkw$> Dempo | Southeastern Sumatra | 4.016°S, 103.121°E | Summit elev. 3142 m According to a news article the public was reminded to stay 1 km away from Dempoâ??s main crater and as far as 2 km on the N flank because of potential eruptions and toxic gases. The crater lake was turquoise green on 5 August and gray on 8 August. The Alert Level remained at 2 (on a scale of 1-4). Geologic Summary. Dempo is a stratovolcano that rises above the Pasumah Plain of SE Sumatra. The andesitic complex has two main peaks, Gunung Dempo and Gunung Marapi, constructed near the SE rim of a 3-km-wide amphitheater open to the north. The high point of the older Gunung Dempo crater rim is slightly lower, and lies at the SE end of the summit complex. The taller Marapi cone was constructed within the older crater. Remnants of seven craters are found at or near the summit, with volcanism migrating WNW over time. The active 750 x 1,100 m active crater cuts the NW side of the Marapi cone and contains a 400-m-wide lake at the far NW end. Eruptions recorded since 1817 have been small-to-moderate explosions that produced local ashfall. Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV-Oa2QuLw$> ; Antara News https://www.antaranews.com/berita/4246547/bpbd-imbau-pendaki-tak-dekati-kawah-gunung-dempo-radius-satu-kilometer <https://urldefense.com/v3/__https://www.antaranews.com/berita/4246547/bpbd-imbau-pendaki-tak-dekati-kawah-gunung-dempo-radius-satu-kilometer__;!!IKRxdwAv5BmarQ!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV9Z1AGVNg$> Dukono | Halmahera | 1.6992°N, 127.8783°E | Summit elev. 1273 m PVMBG reported that the eruption at Dukono was ongoing during 7-13 August. Daily gray-and-white ash plumes rose 100-1,000 m above the summit and drifted SW, W, and NW. 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!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV-Oa2QuLw$> Ebeko | Paramushir Island (Russia) | 50.686°N, 156.014°E | Summit elev. 1103 m KVERT reported that moderate explosive activity was ongoing at Ebeko during 1-8 August. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E), explosions during 4-6 and 8 August generated ash plumes that rose as high as 3.5 km (11,500 ft) a.s.l. and drifted E. Thermal anomalies were identified in satellite images on 5 August; on other days either no activity was observed, or weather conditions prevented views. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates are UTC; specific events are in local time where noted. Geologic Summary. The flat-topped summit of the central cone of Ebeko volcano, one of the most active in the Kuril Islands, occupies the northern end of Paramushir Island. Three summit craters located along a SSW-NNE line form Ebeko volcano proper, at the northern end of a complex of five volcanic cones. Blocky lava flows extend west from Ebeko and SE from the neighboring Nezametnyi cone. The eastern part of the southern crater contains strong solfataras and a large boiling spring. The central crater is filled by a lake about 20 m deep whose shores are lined with steaming solfataras; the northern crater lies across a narrow, low barrier from the central crater and contains a small, cold crescentic lake. Historical activity, recorded since the late-18th century, has been restricted to small-to-moderate explosive eruptions from the summit craters. Intense fumarolic activity occurs in the summit craters, on the outer flanks of the cone, and in lateral explosion craters. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV9RYGTZ-A$> Great Sitkin | Andreanof Islands (USA) | 52.076°N, 176.13°W | Summit elev. 1740 m AVO reported that slow lava effusion in Great Sitkinâ??s summit crater continued during 6-13 August, particularly near the summit and to the ENE; continuing growth was confirmed by 6-7 August satellite images. Seismicity was low with few small daily earthquakes. Elevated surface temperatures were at moderate levels during 10-11 August and at weak levels during 11-13 August. Minor steaming and a diffuse gas plume were visible in webcam and satellites images during 11-13 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!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV8WqcYNmg$> Ibu | Halmahera | 1.488°N, 127.63°E | Summit elev. 1325 m PVMBG reported that activity at Ibu continued during 7-13 August and multiple eruptive events were recorded daily. Gray or white-and-gray ash plumes that were sometimes dense rose as high as 1 km above the summit and drifted in multiple directions on most days; weather conditions occasionally obscured views, especially on 8 August. Daily webcam images posted with the reports showed incandescence emanating above the crater rim, possibly reflected in the emissions. The Alert Level remained at 3 (the second highest level on a four-level scale) and the public was advised to stay 4 km away from the active crater and 5 km away from the N crater wall opening. Geologic Summary. The truncated summit of Gunung Ibu stratovolcano along the NW coast of Halmahera Island has large nested summit craters. The inner crater, 1 km wide and 400 m deep, has contained several small crater lakes. The 1.2-km-wide outer crater is breached on the N, creating a steep-walled valley. A large cone grew ENE of the summit, and a smaller one to the WSW has fed a lava flow down the W flank. A group of maars is located below the N and W flanks. The first observed and recorded eruption was a small explosion from the summit crater in 1911. Eruptive activity began again in December 1998, producing a lava dome that eventually covered much of the floor of the inner summit crater along with ongoing explosive ash emissions. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV-Oa2QuLw$> Ijen | Eastern Java | 8.058°S, 114.242°E | Summit elev. 2769 m PVMBG reported that after a period of elevated seismicity at Ijen during 12-22 July, the number and magnitude of seismic events began to decrease. Realtime Seismic Amplitude Measurement (RSAM) data showed that the intensity of the seismicity began to decline on 13 July and, although there were fluctuations, seismicity had almost returned to normal levels. Visual observations during 1-12 August indicated that the color of the lake was the usual turquoise green, gas bubbles were not visible, there were fewer sulfur spherules, and white steam was not rising from the surface of the lake. The temperature of the crater lake water was 42.2-43.4 degrees Celsius. Dense white solfatara plumes rose from vents. A sulfur odor was present, but it was not strong. The lake water was 15.3 m below the dam. At 1300 on 13 August the Alert level was lowered to 1 (on a scale of 1-4) and residents, visitors, and miners were advised to not approach the crater rim, go down inside the crater, or stay overnight within 500 m of the crater rim. Geologic Summary. The Ijen volcano complex at the eastern end of Java consists of a group of small stratovolcanoes constructed within the 20-km-wide Ijen (Kendeng) caldera. The north caldera wall forms a prominent arcuate ridge, but elsewhere the rim was buried by post-caldera volcanoes, including Gunung Merapi, which forms the high point of the complex. Immediately west of the Gunung Merapi stratovolcano is the historically active Kawah Ijen crater, which contains a nearly 1-km-wide, turquoise-colored, acid lake. Kawah Ijen is the site of a labor-intensive mining operation in which baskets of sulfur are hand-carried from the crater floor. Many other post-caldera cones and craters are located within the caldera or along its rim. The largest concentration of cones forms an E-W zone across the southern side of the caldera. Coffee plantations cover much of the caldera floor; nearby waterfalls and hot springs are tourist destinations. 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!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV-Oa2QuLw$> Kanlaon | Philippines | 10.4096°N, 123.13°E | Summit elev. 2422 m PHIVOLCS issued a special notice for Kanlaon at 2330 on 10 August noting increased sulfur dioxide emissions. Earlier in the day a Flyspec instrument measured an average of 4,839 tonnes per day (t/d) of sulfur dioxide emissions at the summit crater, the third highest value recorded in 2024. Gas emissions rose 400-600 m above the carter rim and drifted SE and NE during 10-13 August. Another special notice was issued at 1830 on 13 August noting that the Flyspec instrument measured an average of 7,307 t/d, the highest sulfur dioxide emissions ever recorded at the volcano. Higher sulfur dioxide gas fluxes had been recorded in 2024 with an average of 1,273 t/d prior to the 3 June eruption; afterward the eruption emissions were elevated, averaging 3,102 t/d. An average of nine volcanic earthquakes per day also persisted after the 3 June eruption. Ground deformation data from continuous GPS and electronic tilt data indicated inflation of the volcano since March 2022 and specifically at the E flank starting in 2023. The Alert Level remained at 1 (on a scale of 0-5) and PHIVOLCS reminded the public to remain outside of the 4-km-radius Permanent Danger Zone. Geologic Summary. Kanlaon volcano (also spelled Canlaon) forms the highest point on the Philippine island of Negros. The massive andesitic stratovolcano is covered with fissure-controlled pyroclastic cones and craters, many of which are filled by lakes. The largest debris avalanche known in the Philippines traveled 33 km SW from Kanlaon. The summit contains a 2-km-wide, elongated northern caldera with a crater lake and a smaller but higher active vent, Lugud crater, to the south. Eruptions recorded since 1866 have typically consisted of phreatic explosions of small-to-moderate size that produce minor local ashfall. Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS) http://www.phivolcs.dost.gov.ph/ <https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV8jndHF-A$> Karangetang | Sangihe Islands | 2.781°N, 125.407°E | Summit elev. 1797 m PVMBG reported that heavy rain that began at noon on 7 August generated lahars at around 1230 and 1239 that descended Karangetangâ??s Nanitu, Timbelang, and Batuawang drainages on the W, SW, and S flanks, respectively. The lahar deposit in the Batuawang drainage varied between 5 cm and 1.5 m thickness and blocked a 150-m-long section of the Ondong-Ulu Siau Road. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 1.5 km away from both Main Crater and North Crater and 2.5 km away on the S and SE flanks. Geologic Summary. Karangetang (Api Siau) volcano lies at the northern end of the island of Siau, about 125 km NNE of the NE-most point of Sulawesi. The stratovolcano contains five summit craters along a N-S line. It is one of Indonesia's most active volcanoes, with more than 40 eruptions recorded since 1675 and many additional small eruptions that were not documented (Neumann van Padang, 1951). Twentieth-century eruptions have included frequent explosive activity sometimes accompanied by pyroclastic flows and lahars. Lava dome growth has occurred in the summit craters; collapse of lava flow fronts have produced pyroclastic flows. Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV-Oa2QuLw$> ; Antara News https://www.antaranews.com/berita/4245287/badan-geologi-waspada-banjir-lahar-dingin-gunung-karangetang <https://urldefense.com/v3/__https://www.antaranews.com/berita/4245287/badan-geologi-waspada-banjir-lahar-dingin-gunung-karangetang__;!!IKRxdwAv5BmarQ!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV91lqygdA$> Karymsky | Eastern Kamchatka (Russia) | 54.049°N, 159.443°E | Summit elev. 1513 m KVERT reported moderate levels of activity at Karymsky during 1-8 August. A thermal anomaly over the volcano was identified in satellite images during 3-5 and 7 August; weather clouds obscured views on the other days during the week. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted. Geologic Summary. Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed during the early Holocene. The caldera cuts the south side of the Pleistocene Dvor volcano and is located outside the north margin of the large mid-Pleistocene Polovinka caldera, which contains the smaller Akademia Nauk and Odnoboky calderas. Most seismicity preceding Karymsky eruptions originated beneath Akademia Nauk caldera, located immediately south. The caldera enclosing Karymsky formed about 7600-7700 radiocarbon years ago; construction of the stratovolcano began about 2000 years later. The latest eruptive period began about 500 years ago, following a 2300-year quiescence. Much of the cone is mantled by lava flows less than 200 years old. Historical eruptions have been vulcanian or vulcanian-strombolian with moderate explosive activity and occasional lava flows from the summit crater. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV9RYGTZ-A$> Lewotobi | Flores Island | 8.542°S, 122.775°E | Summit elev. 1703 m PVMBG reported that eruptive activity at Lewotobiâ??s Laki-laki volcano continued during 7-13 August. Daily gray or white-and-gray ash plumes that were sometimes dense rose as high as 1 km above the summit and drifted mainly SW, W, and NW. Eruptive events were sometimes recorded on other days but weather conditions prevented visual observations. Incandescence near the summit crater was visible in webcam images during 9-10 August. The Alert Level remained at 3 (the second highest level on a scale of 1-4) and the public was warned to stay outside of the exclusion zone, defined as a 3-km radius around both Laki-laki and Perempuan craters, 4 km to the NNW and SSE of Laki-laki. Geologic Summary. The Lewotobi edifice in eastern Flores Island is composed of the two adjacent Lewotobi Laki-laki and Lewotobi Perempuan stratovolcanoes (the "husband and wife"). Their summits are less than 2 km apart along a NW-SE line. The conical Laki-laki to the NW has been frequently active during the 19th and 20th centuries, while the taller and broader Perempuan has had observed eruptions in 1921 and 1935. Small lava domes have grown during the 20th century in both of the summit craters, which are open to the north. A prominent cone, Iliwokar, occurs on the E flank of Perampuan. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV-Oa2QuLw$> Merapi | Central Java | 7.54°S, 110.446°E | Summit elev. 2910 m BPPTKG reported that the eruption at Merapi (on Java) continued during 2-8 August. Earthquakes were less intense compared to the previous week. The SW lava dome produced 223 lava avalanches that traveled as far as 1.9 km down the upper part of the Bebeng drainage. Morphological changes to the SW lava dome were due to continuing effusion and collapses of material, and slight changes were detected at the dome in the main crater. The volume of the SW dome was an estimated 2,628,300 cubic meters and the dome in the main crater was stable at an estimated 2,360,700 cubic meters based on webcam images and a 2 August drone survey. The hottest temperature at the SW dome was around 249 degrees Celsius, higher than 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!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV9Fx1jL3Q$> Rincon de la Vieja | Costa Rica | 10.83°N, 85.324°W | Summit elev. 1916 m OVSICORI-UNA reported that steam-and-gas emissions at Rincón de la Vieja were continuous for a period of time starting the morning of 9 August before they intensified around 0800. At 1240 a small phreatic event produced a gas-and-steam plume that rose 700 m above the crater rim and drifted E. During 11-12 August seismicity was characterized by intermittent, low-intensity tremor and sporadic, long-period tornillo-type events. A small phreatic event was recorded at 0211 on 12 August. Geologic Summary. Rincón de la Vieja, the largest volcano in NW Costa Rica, is a remote volcanic complex in the Guanacaste Range. The volcano consists of an elongated, arcuate NW-SE-trending ridge constructed within the 15-km-wide early Pleistocene GuachipelÃn caldera, whose rim is exposed on the south side. Sometimes known as the "Colossus of Guanacaste," it has an estimated volume of 130 km3 and contains at least nine major eruptive centers. Activity has migrated to the SE, where the youngest-looking craters are located. The twin cone of Santa MarÃa volcano, the highest peak of the complex, is located at the eastern end of a smaller, 5-km-wide caldera and has a 500-m-wide crater. A Plinian eruption producing the 0.25 km3 RÃo Blanca tephra about 3,500 years ago was the last major magmatic eruption. All subsequent eruptions, including numerous historical eruptions possibly dating back to the 16th century, have been from the prominent active crater containing a 500-m-wide acid lake located ENE of Von Seebach crater. Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA) http://www.ovsicori.una.ac.cr/ <https://urldefense.com/v3/__http://www.ovsicori.una.ac.cr/__;!!IKRxdwAv5BmarQ!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV9ePKAcOw$> Sabancaya | Peru | 15.787°S, 71.857°W | Summit elev. 5960 m Instituto GeofÃsico del Perú (IGP) reported that the eruption at Sabancaya continued during 5-11 August with a daily average of 48 explosions. Gas-and-ash plumes rose as high as 1.5 km above the summit and drifted less than 10 km S and SE. Thermal anomalies over the lava dome in the summit crater were identified in satellite data. Slight inflation was detected N of Hualca Hualca (7 km N). Sulfur dioxide emissions were at low levels, averaging 158 tons per day. The Alert Level remained at Orange (the third level on a four-color scale) and the public was warned to stay outside of a 12 km radius. Geologic Summary. Sabancaya, located in the saddle NE of Ampato and SE of Hualca Hualca volcanoes, is the youngest of these volcanic centers and the only one to have erupted in historical time. The oldest of the three, Nevado Hualca Hualca, is of probable late-Pliocene to early Pleistocene age. The name Sabancaya (meaning "tongue of fire" in the Quechua language) first appeared in records in 1595 CE, suggesting activity prior to that date. Holocene activity has consisted of Plinian eruptions followed by emission of voluminous andesitic and dacitic lava flows, which form an extensive apron around the volcano on all sides but the south. Records of observed eruptions date back to 1750 CE. Source: Instituto GeofÃsico del Perú (IGP) http://www.igp.gob.pe/ <https://urldefense.com/v3/__http://www.igp.gob.pe/__;!!IKRxdwAv5BmarQ!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV8YiHvYLQ$> Semeru | Eastern Java | 8.108°S, 112.922°E | Summit elev. 3657 m PVMBG reported that eruptive activity continued at Semeru during 7-13 August with multiple daily eruptive events recorded by the seismic network. White-and-gray ash plumes that were sometimes dense rose 400-800 m above the summit and drifted in multiple directions on most days; weather conditions sometimes prevented visual conformation of the eruptive events, especially on 8 and 13 August. The Alert Level remained at 2 (the second lowest level on a scale of 1-4). The public was warned to stay at least 5 km away from the summit in all directions, 13 km from the summit to the SE, 500 m from the banks of the Kobokan drainage as far as 17 km from the summit, and to avoid other drainages including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards. Geologic Summary. Semeru, the highest volcano on Java, and one of its most active, lies at the southern end of a volcanic massif extending north to the Tengger caldera. The steep-sided volcano, also referred to as Mahameru (Great Mountain), rises above coastal plains to the south. Gunung Semeru was constructed south of the overlapping Ajek-ajek and Jambangan calderas. A line of lake-filled maars was constructed along a N-S trend cutting through the summit, and cinder cones and lava domes occupy the eastern and NE flanks. Summit topography is complicated by the shifting of craters from NW to SE. Frequent 19th and 20th century eruptions were dominated by small-to-moderate explosions from the summit crater, with occasional lava flows and larger explosive eruptions accompanied by pyroclastic flows that have reached the lower flanks of the volcano. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV-Oa2QuLw$> Sheveluch | Central Kamchatka (Russia) | 56.653°N, 161.36°E | Summit elev. 3283 m KVERT reported that thermal anomalies over both the â??300 years of RASâ?? dome on the SW flank of Old Sheveluch and the lava dome in the crater of Young Sheveluch were identified in satellite images during 2-6 August. Plumes of resuspended ash drifted 210 km SE during 3-5 August. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted. Geologic Summary. 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!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV9RYGTZ-A$> 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 5-12 August. Crater incandescence was observed nightly in webcam images. Eruptive events were recorded at 2109 on 6 August, at 0056, 0124, 0236, 0313, 0349, 0657, and 0955 on 7 August, and at 0207, 1156, 1225, and 1440 on 8 August. Ash plumes rose 1-1.4 km above the crater rim and drifted mainly SW, S, and SE. Explosions were recorded at 1457, 1625, and 1717 on 10 August, though emissions were not visually observed. Explosions at 2103 on 10 August, at 1011 and 1213 on 11 August, and at 0054 and 0207 on 12 August generated ash plumes that rose 200-600 m above the crater rim and drifted SE; sometimes the plumes rose into weather clouds. 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!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV9ZxpTdkw$> Taal | Luzon (Philippines) | 14.0106°N, 120.9975°E | Summit elev. 311 m PHIVOLCS reported ongoing, low-level unrest at Taal during 6-13 August. Daily steam-and-gas plumes rose as high as 1.2 km above the crater rim and drifted NE and ENE. Four volcanic earthquakes were recorded during 6-7 August and a volcanic tremor signal lasting one minute occurred during 7-8 August . Sulfur dioxide emissions averaged 5,094 tonnes per day (t/d) on 8 August and 2,655 t/d on 12 August. Hot fluids were visible upwelling in the lake during 10-13 August. A one-minute phreatic event was detected during 11-12 August. The Alert Level remained at 1 (on a scale of 0-5), and PHIVOLCS reminded the public that the entire Taal Volcano Island was a Permanent Danger Zone (PDZ) and to take extra precautions around Main Crater, when boating on Taal Lake, and along the Daang Kastila fissure. Geologic Summary. Taal is one of the most active volcanoes in the Philippines and has produced some powerful eruptions. The 15 x 20 km Talisay (Taal) caldera is largely filled by Lake Taal, whose 267 km2 surface lies only 3 m above sea level. The maximum depth of the lake is 160 m, with several submerged eruptive centers. The 5-km-wide Volcano Island in north-central Lake Taal is the location of all observed eruptions. The island is composed of coalescing small stratovolcanoes, tuff rings, and scoria cones. Powerful pyroclastic flows and surges have caused many fatalities. Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS) http://www.phivolcs.dost.gov.ph/ <https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!diGOW78THfoWLOn6S77YLmEdkMNXWR5elv-BJRt7UpNX4UH4rZOjIwRA--8F1Go_8MFhfYyI6nRgd7ppZV8jndHF-A$> 7-7-7-7-7-7-7-7-7-7-7-7-7-7 ============================================================== 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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