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 16-22 February 2022 Sally Kuhn Sennert - Weekly Report Editor (kuhns@xxxxxx) URL: https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0i2fibgU$ <https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6W7AmsCQ$> New Activity/Unrest: Sangeang Api, N of Sumbawa Island Ongoing Activity: Aira, Kyushu (Japan) | Ambae, Vanuatu | Davidof, Aleutian Islands (USA) | Etna, Sicily (Italy) | Great Sitkin, Andreanof Islands (USA) | Hunga Tonga-Hunga Ha'apai, Tonga Ridge | Karymsky, Eastern Kamchatka (Russia) | Kavachi, Solomon Islands | Kilauea, Hawaiian Islands (USA) | Lewotolok, Lembata Island | Merapi, Central Java | Pavlof, Alaska Peninsula, Alaska | Reventador, Ecuador | Semeru, Eastern Java | Semisopochnoi, Aleutian Islands (USA) | Sheveluch, Central Kamchatka (Russia) | Suwanosejima, Ryukyu Islands (Japan) | Turrialba, Costa Rica | Wolf, Isla Isabela (Galapagos) | 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 Sangeang Api | N of Sumbawa Island | 8.2°S, 119.07°E | Summit elev. 1912 m The Darwin VAAC reported that on 17 February ash plumes from Sangeang Api rose to altitudes of 4-4.9 km (13,000-16,000 ft) a.s.l. and drifted SW and WSW. The Alert Level remained at 2 (on a scale of 1-4). Geologic Summary. Sangeang Api volcano, one of the most active in the Lesser Sunda Islands, forms a small 13-km-wide island off the NE coast of Sumbawa Island. Two large trachybasaltic-to-tranchyandesitic volcanic cones, Doro Api and Doro Mantoi, were constructed in the center and on the eastern rim, respectively, of an older, largely obscured caldera. Flank vents occur on the south side of Doro Mantoi and near the northern coast. Intermittent eruptions have been recorded since 1512, most of them during in the 20th century. Sources: Darwin Volcanic Ash Advisory Centre (VAAC) https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0b66BIQE$ <https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6Gzkmr4A$> ; Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0lC63zXU$ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o63NyqvBk$> Ongoing Activity Aira | Kyushu (Japan) | 31.593°N, 130.657°E | Summit elev. 1117 m JMA reported that at 1540 on 15 February an eruption at Minamidake Crater (at Aira Calderaâ??s Sakurajima volcano) produced plumes that rose 1.3 km above the crater rim and into weather clouds. Sulfur dioxide emissions were slightly high at 1,200 tons per day on 17 February. A very small eruptive event was recorded on 20 February. The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from the crater. Geologic Summary. The Aira caldera in the northern half of Kagoshima Bay contains the post-caldera Sakurajima volcano, one of Japan's most active. Eruption of the voluminous Ito pyroclastic flow accompanied formation of the 17 x 23 km caldera about 22,000 years ago. The smaller Wakamiko caldera was formed during the early Holocene in the NE corner of the Aira caldera, along with several post-caldera cones. The construction of Sakurajima began about 13,000 years ago on the southern rim of Aira caldera and built an island that was finally joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kitadake summit cone ended about 4850 years ago, after which eruptions took place at Minamidake. Frequent historical eruptions, recorded since the 8th century, have deposited ash on Kagoshima, one of Kyushu's largest cities, located across Kagoshima Bay only 8 km from the summit. The largest historical eruption took place during 1471-76. Source: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0QO_k2QY$ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6QGyspRE$> Ambae | Vanuatu | 15.389°S, 167.835°E | Summit elev. 1496 m On 18 February the Vanuatu Meteorology and Geo-Hazards Department (VMGD) reported that the cone in Ambaeâ??s Lake Voui continued to grow and produce steam, gas, and ash emissions. Webcam images showed ash emissions rising to 3 km (10,000 ft) a.s.l. and drifting WSW the day before, according to the Wellington VAAC. The Alert Level remained at 2 (on a scale of 0-5) and the public was warned to stay outside of the Danger Zone defined as a 2-km radius around the active vents in Lake Voui and away from drainages during heavy rains. Geologic Summary. The island of Ambae, also known as Aoba, is a massive 2,500 km3 basaltic shield that is the most voluminous volcano of the New Hebrides archipelago. A pronounced NE-SW-trending rift zone dotted with scoria cones gives the 16 x 38 km island an elongated form. A broad pyroclastic cone containing three crater lakes (Manaro Ngoru, Voui, and Manaro Lakua) is located at the summit within the youngest of at least two nested calderas, the largest of which is 6 km in diameter. That large central edifice is also called Manaro Voui or Lombenben volcano. Post-caldera explosive eruptions formed the summit craters about 360 years ago. A tuff cone was constructed within Lake Voui (or Vui) about 60 years later. The latest known flank eruption, about 300 years ago, destroyed the population of the Nduindui area near the western coast. Sources: Vanuatu Meteorology and Geo-Hazards Department (VMGD) https://urldefense.com/v3/__http://www.geohazards.gov.vu/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F04BDaBqk$ <https://urldefense.com/v3/__http://www.geohazards.gov.vu/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o63qJXWaY$> ; Wellington Volcanic Ash Advisory Center (VAAC) https://urldefense.com/v3/__http://vaac.metservice.com/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0IwRsTX8$ <https://urldefense.com/v3/__http://vaac.metservice.com/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6BWyG5u4$> Davidof | Aleutian Islands (USA) | 51.97°N, 178.33°E | Summit elev. 328 m According to AVO the earthquake swarm that began on 24 January in the vicinity at Davidof continued at least through 22 February with a few small earthquakes recorded on most days. The swarm was either related to tectonic processes or volcanic unrest. The Aviation Color Code remained at Yellow and the Volcano Alert Level remained at Advisory. Geologic Summary. A cluster of small islands between Segula and Little Sitkin in the western Aleutians, the largest of which is Davidof, are remnants of a stratovolcano that collapsed during the late Tertiary, forming a 2.7-km-wide caldera. The islands include Khvostof, Pyramid, Lopy, and Davidof; the latter three form the eastern rim of the mostly submarine caldera, sometimes referred to as the "Aleutian Krakatau." The islands were constructed above a roughly 100-m-deep submarine platform extending NW to Segula Island; the floor of the caldera lies 80 m below sea level. The islands are vegetated, but lava flows are recognizable, and Smith et al. (1978) suggested a possible Holocene age. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0cV9T4K0$ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o60WU3UmU$> Etna | Sicily (Italy) | 37.748°N, 14.999°E | Summit elev. 3320 m INGV reported that a thermal anomaly at Etnaâ??s Southeast Crater (SEC) was first visible in webcam images at 0907 on 21 February, followed within an hour by weak Strombolian activity. Strombolian activity intensified and by noon lava fountaining was visible. An eruption plume had risen to 10 km above the summit and drifted SE. Lava overflowed the SEC at 1210 and traveled SW. The eruption plume reached a height of 12 km, drifted SSE, and caused ashfall in Viagrande (16 km SSE), Trecastagni (16 km SE), Milo (about 11 km ESE), Aci Castello (26 km SSE), and Zafferana (10 km SE). Sometime after 1300 lava fountaining ceased, though the lava flow continued to be fed. Another flow traveling E to an elevation of 2,900 m was visible in webcam images and by scientists observing the eruption in the field. Explosivity activity ceased in the afternoon. Weather conditions hindered views over the next day but by 1900 on 22 February webcam observations were again possible. Weak Strombolian activity at SEC was visible and the E lava flow had advanced. 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!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0WqLPftc$ <https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o62QCf7QY$> Great Sitkin | Andreanof Islands (USA) | 52.076°N, 176.13°W | Summit elev. 1740 m AVO reported that slow lava effusion at Great Sitkin continued during 16-22 February, though cloudy conditions often prevented satellite and webcam views. Lava flows had continued to advance down the S, W, and N flanks, and were 1,050 m, 930 m, and 220 m long, respectively. Lava flows were also active on the SSW flank. Seismicity remained slightly above background levels, and a few, daily, small local earthquakes were recorded during 19-21 February. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively. Geologic Summary. The Great Sitkin volcano forms much of the northern side of Great Sitkin Island. A younger parasitic volcano capped by a small, 0.8 x 1.2 km ice-filled summit caldera was constructed within a large late-Pleistocene or early Holocene scarp formed by massive edifice failure that truncated an ancestral volcano and produced a submarine debris avalanche. Deposits from this and an older debris avalanche from a source to the south cover a broad area of the ocean floor north of the volcano. The summit lies along the eastern rim of the younger collapse scarp. Deposits from an earlier caldera-forming eruption of unknown age cover the flanks of the island to a depth up to 6 m. The small younger caldera was partially filled by lava domes emplaced in 1945 and 1974, and five small older flank lava domes, two of which lie on the coastline, were constructed along northwest- and NNW-trending lines. Hot springs, mud pots, and fumaroles occur near the head of Big Fox Creek, south of the volcano. Historical eruptions have been recorded since the late-19th century. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0cV9T4K0$ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o60WU3UmU$> Hunga Tonga-Hunga Ha'apai | Tonga Ridge | 20.536°S, 175.382°W | Summit elev. 114 m Recovery efforts from the 14-15 January eruption of Hunga Tonga-Hunga Ha'apai continued in Tonga. According to a news article, the main undersea international fiber-optic communication cable that had been severed in multiple places due to the eruption had been repaired by 21 February, and internet connectivity was restored by 22 February. Repairs had begun on 3 February to rejoin 5-6 pieces and replace a 55 km section of the cable that was missing and likely buried in sediment. A domestic cable that was located closer to the volcano may take months to repair. Another news article noted that over 200 fishing boats had been destroyed by the tsunamis; dozens of new boats had been gifted by international donors. Geologic Summary. The small andesitic islands of Hunga Tonga and Hunga Ha'apai are part of the western and northern remnants of the rim (~6 km diameter) of a largely submarine caldera located about 30 km SSE of Falcon Island. The topmost sequence of welded and unwelded ignimbrite units from a caldera-forming eruption was 14C dated to 1040-1180 CE (Cronin et al., 2017; Brenna et al. 2022). At least two additional welded pumice-rich ignimbrite units and nonwelded pyroclastic flow deposits, below paleosols and other volcaniclastic deposits, indicated more very large previous eruptions (Cronin et al., 2017; Brenna et al. 2022). Several submarine eruptions have occurred at this caldera system since the first recorded eruption in 1912, including 1937 and S of the islands in 1988. A short eruption in 2009 added land to to Hunga Ha'apai. At that time the two islands were each about 2 km long, displaying inward-facing sea cliffs with lava and tephra layers dipping gently away from the caldera. An eruption during December 2014-January 2015 was centered between the islands, and combined them into one larger structure. Major explosive eruptions in late 2021 initially reshaped the central part of the combined island before stronger activity in mid-January 2022 removed most of the 2014-15 material; an even larger eruption the next day sent an eruption plume high into the stratosphere, triggered shock waves through the atmosphere and tsunami across the Pacific Ocean, and left only small remnants of the islands above the ocean surface. Sources: Matangi Tonga Online https://urldefense.com/v3/__https://matangitonga.to/2022/02/21/200-fishing-boats-wrecked-tsunamis__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0DtWqdPM$ <https://urldefense.com/v3/__https://matangitonga.to/2022/02/21/200-fishing-boats-wrecked-tsunamis__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6mvn_XXE$> ; Matangi Tonga Online https://urldefense.com/v3/__https://matangitonga.to/2022/02/21/reliance-reconnecting-tonga-end-cable-tuesday-countdown-launch__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0uVf0u8s$ <https://urldefense.com/v3/__https://matangitonga.to/2022/02/21/reliance-reconnecting-tonga-end-cable-tuesday-countdown-launch__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6mY5GZtE$> ; Matangi Tonga Online https://urldefense.com/v3/__https://matangitonga.to/2022/02/23/tonga-thanks-elon-musk-spacex-50-vsat-terminals__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0bF-9fX8$ <https://urldefense.com/v3/__https://matangitonga.to/2022/02/23/tonga-thanks-elon-musk-spacex-50-vsat-terminals__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6l-Rn_bU$> ; Associated Press https://urldefense.com/v3/__https://apnews.com/article/spacex-coronavirus-pandemic-technology-business-health-104298b3b7f4fd4773d1021b26302cb6__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0q9D2sCQ$ <https://urldefense.com/v3/__https://apnews.com/article/spacex-coronavirus-pandemic-technology-business-health-104298b3b7f4fd4773d1021b26302cb6__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6PU55meo$> Karymsky | Eastern Kamchatka (Russia) | 54.049°N, 159.443°E | Summit elev. 1513 m KVERT reported that a thermal anomaly over Karymsky was visible in satellite images during 10-11 February. The volcano was either quiet or obscured by clouds on the other days through 18 February. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted. Geologic Summary. Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed during the early Holocene. The caldera cuts the south side of the Pleistocene Dvor volcano and is located outside the north margin of the large mid-Pleistocene Polovinka caldera, which contains the smaller Akademia Nauk and Odnoboky calderas. Most seismicity preceding Karymsky eruptions originated beneath Akademia Nauk caldera, located immediately south. The caldera enclosing Karymsky formed about 7600-7700 radiocarbon years ago; construction of the stratovolcano began about 2000 years later. The latest eruptive period began about 500 years ago, following a 2300-year quiescence. Much of the cone is mantled by lava flows less than 200 years old. Historical eruptions have been vulcanian or vulcanian-strombolian with moderate explosive activity and occasional lava flows from the summit crater. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0UBwUFCI$ <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6hAjzHBM$> Kavachi | Solomon Islands | 8.991°S, 157.979°E | Summit elev. -20 m Satellite data showed discolored water around Kavachi in the month of February, on three of four image acquisition dates. Discolored water fanned out short distances (around 3 km) mainly to the E on 4 February and to the WSW on 14 February. Cloudy weather prevented views of the vent area on 9 February. On 19 February a relatively narrow plume of discolored water drifted E and then dispersed about 6 km away. Geologic Summary. Named for a sea-god of the Gatokae and Vangunu peoples, Kavachi is one of the most active submarine volcanoes in the SW Pacific, located in the Solomon Islands south of Vangunu Island. Sometimes referred to as Rejo te Kvachi ("Kavachi's Oven"), this shallow submarine basaltic-to-andesitic volcano has produced ephemeral islands up to 1 km long many times since its first recorded eruption during 1939. Residents of the nearby islands of Vanguna and Nggatokae (Gatokae) reported "fire on the water" prior to 1939, a possible reference to earlier eruptions. The roughly conical edifice rises from water depths of 1.1-1.2 km on the north and greater depths to the SE. Frequent shallow submarine and occasional subaerial eruptions produce phreatomagmatic explosions that eject steam, ash, and incandescent bombs. On a number of occasions lava flows were observed on the ephemeral islands. Sources: Sentinel Hub https://urldefense.com/v3/__https://sentinel-hub.com/explore/sentinel-playground__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0SlKSeU8$ <https://urldefense.com/v3/__https://sentinel-hub.com/explore/sentinel-playground__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6Gp307aY$> ; Culture Volcan https://urldefense.com/v3/__https://laculturevolcan.blogspot.com/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0HIykfl0$ <https://urldefense.com/v3/__https://laculturevolcan.blogspot.com/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6gCummO8$> Kilauea | Hawaiian Islands (USA) | 19.421°N, 155.287°W | Summit elev. 1222 m HVO reported that lava effusion at the vent of the main cone in the lower W wall of Kilaueaâ??s Halema`uma`u Crater continued at variable rates during 16-22 February. Effusion from the vent was very low or had paused from around 0000 on 16 February until about 0230 on 17 February. After another drop, the effusion rate was relatively stable at least through 22 February. The lake level fluctuated through the week, likely reflecting the lava supply along with periods of inflation and deflation. Short-lived lava ooze-outs were visible along the W margins of the lava lake and small flows from the W vent traveled S and W during 20-22 February. The Aviation Color Code and the Volcano Alert Level remained at Orange and Watch, respectively. Geologic Summary. Kilauea overlaps the E flank of the massive Mauna Loa shield volcano in the island of Hawaii. Eruptions are prominent in Polynesian legends; written documentation since 1820 records frequent summit and flank lava flow eruptions interspersed with periods of long-term lava lake activity at Halemaumau crater in the summit caldera until 1924. The 3 x 5 km caldera was formed in several stages about 1,500 years ago and during the 18th century; eruptions have also originated from the lengthy East and Southwest rift zones, which extend to the ocean in both directions. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1,100 years old; 70% of the surface is younger than 600 years. The long-term eruption from the East rift zone between 1983 and 2018 produced lava flows covering more than 100 km2, destroyed hundreds of houses, and added new coastline. Source: US Geological Survey Hawaiian Volcano Observatory (HVO) https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F071rE_2k$ <https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6C9a7oo8$> Lewotolok | Lembata Island | 8.274°S, 123.508°E | Summit elev. 1431 m PVMBG reported that the eruption at Lewotolok continued during 15-19 February. Daily white-and-gray ash plumes rose as high as 600 m above the summit and drifted E, W, and NW. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 3 km away from the summit crater and 4 km away from the crater on the SE flank. Geologic Summary. The Lewotolok (or Lewotolo) stratovolcano occupies the eastern end of an elongated peninsula extending north into the Flores Sea, connected to Lembata (formerly Lomblen) Island by a narrow isthmus. It is symmetrical when viewed from the north and east. A small cone with a 130-m-wide crater constructed at the SE side of a larger crater forms the volcano's high point. Many lava flows have reached the coastline. Eruptions recorded since 1660 have consisted of explosive activity from the summit crater. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0lC63zXU$ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o63NyqvBk$> Merapi | Central Java | 7.54°S, 110.446°E | Summit elev. 2910 m BPPTKG reported no significant morphological changes at Merapiâ??s lava domes, located just below the SW rim and in the summit crater, during 11-17 February. Seismicity remained at high levels. In the SW-flank Bebeng drainage there were as many as 105 lava avalanches that traveled a maximum of 2 km and three pyroclastic flows that extended 2.8 km. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-5 km away from the summit based on location. Geologic Summary. Merapi, one of Indonesia's most active volcanoes, lies in one of the world's most densely populated areas and dominates the landscape immediately north of the major city of Yogyakarta. It is the youngest and southernmost of a volcanic chain extending NNW to Ungaran volcano. Growth of Old Merapi during the Pleistocene ended with major edifice collapse perhaps about 2,000 years ago, leaving a large arcuate scarp cutting the eroded older Batulawang volcano. Subsequent growth of the steep-sided Young Merapi edifice, its upper part unvegetated due to frequent activity, began SW of the earlier collapse scarp. Pyroclastic flows and lahars accompanying growth and collapse of the steep-sided active summit lava dome have devastated cultivated lands on the western-to-southern flanks and caused many fatalities. Source: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG) https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0Tw7jryU$ <https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6E9muGEk$> Pavlof | Alaska Peninsula, Alaska | 55.417°N, 161.894°W | Summit elev. 2493 m AVO reported that the eruption at Pavlof was ongoing during 16-22 February with lava effusion from a vent on the upper SE flank feeding flows on the E flank. Seismicity was elevated with periods of tremor detected and elevated surface temperatures identified in satellite images; both were consistent with continuing lava effusion. The Volcano Alert Level remained at Watch and the Aviation Color Code remained at Orange. Geologic Summary. The most active volcano of the Aleutian arc, Pavlof is a 2519-m-high Holocene stratovolcano that was constructed along a line of vents extending NE from the Emmons Lake caldera. Pavlof and its twin volcano to the NE, 2142-m-high Pavlof Sister, form a dramatic pair of symmetrical, glacier-covered stratovolcanoes that tower above Pavlof and Volcano bays. A third cone, Little Pavlof, is a smaller volcano on the SW flank of Pavlof volcano, near the rim of Emmons Lake caldera. Unlike Pavlof Sister, Pavlof has been frequently active in historical time, typically producing Strombolian to Vulcanian explosive eruptions from the summit vents and occasional lava flows. The active vents lie near the summit on the north and east sides. The largest historical eruption took place in 1911, at the end of a 5-year-long eruptive episode, when a fissure opened on the N flank, ejecting large blocks and issuing lava flows. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0cV9T4K0$ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o60WU3UmU$> Reventador | Ecuador | 0.077°S, 77.656°W | Summit elev. 3562 m IG reported that a high level of activity continued at Reventador during 15-22 February, though cloudy weather conditions prevented visual observations during 20-21 February. Steam-and-ash plumes, often observed multiple times a day with the webcam or reported by the Washington VAAC, rose higher than 1.3 km above the summit crater and drifted in multiple directions. Crater incandescence was visible most nights; incandescent material was visible descending the S flank during 17-18 February. Geologic Summary. Reventador is the most frequently active of a chain of Ecuadorian volcanoes in the Cordillera Real, well east of the principal volcanic axis. The forested, dominantly andesitic Volcán El Reventador stratovolcano rises to 3562 m above the jungles of the western Amazon basin. A 4-km-wide caldera widely breached to the east was formed by edifice collapse and is partially filled by a young, unvegetated stratovolcano that rises about 1300 m above the caldera floor to a height comparable to the caldera rim. It has been the source of numerous lava flows as well as explosive eruptions that were visible from Quito in historical time. Frequent lahars in this region of heavy rainfall have constructed a debris plain on the eastern floor of the caldera. The largest historical eruption took place in 2002, producing a 17-km-high eruption column, pyroclastic flows that traveled up to 8 km, and lava flows from summit and flank vents. Source: Instituto GeofÃsico-Escuela Politécnica Nacional (IG) https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0Pb6Ed_M$ <https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6--i3a_c$> Semeru | Eastern Java | 8.108°S, 112.922°E | Summit elev. 3657 m PVMBG reported that eruptions at Semeru recorded at 0554 and 0709 on 17 February, 0558 on 18 February, 0551 on 19 February, and 0701 on 20 February generated ash plumes that rose 500-700 m above the summit and drifted N, W, and SW. The Alert Level remained at 3 (on a scale of 1-4). The public was warned to stay at least 500 m away from Kobokan drainages within 17 km of the summit, along with other drainages originating on Semeru, including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards. Geologic Summary. Semeru, the highest volcano on Java, and one of its most active, lies at the southern end of a volcanic massif extending north to the Tengger caldera. The steep-sided volcano, also referred to as Mahameru (Great Mountain), rises above coastal plains to the south. Gunung Semeru was constructed south of the overlapping Ajek-ajek and Jambangan calderas. A line of lake-filled maars was constructed along a N-S trend cutting through the summit, and cinder cones and lava domes occupy the eastern and NE flanks. Summit topography is complicated by the shifting of craters from NW to SE. Frequent 19th and 20th century eruptions were dominated by small-to-moderate explosions from the summit crater, with occasional lava flows and larger explosive eruptions accompanied by pyroclastic flows that have reached the lower flanks of the volcano. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0lC63zXU$ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o63NyqvBk$> Semisopochnoi | Aleutian Islands (USA) | 51.93°N, 179.58°E | Summit elev. 1221 m AVO reported that low-level eruptive activity at Semisopochnoi's North Cerberus cone continued during 16-22 February. Seismicity was elevated with low-level tremor, and occasional explosions, detected almost daily in both seismic and infrasound data. Weather clouds prevented satellite and webcam views of the volcano. Low-level ash clouds from the summit were observed in webcam images drifting N during 21-22 February. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch. Geologic Summary. Semisopochnoi, the largest subaerial volcano of the western Aleutians, is 20 km wide at sea level and contains an 8-km-wide caldera. It formed as a result of collapse of a low-angle, dominantly basaltic volcano following the eruption of a large volume of dacitic pumice. The high point of the island is Anvil Peak, a double-peaked late-Pleistocene cone that forms much of the island's northern part. The three-peaked Mount Cerberus was constructed within the caldera during the Holocene. Each of the peaks contains a summit crater; lava flows on the N flank of Cerberus appear younger than those on the south side. Other post-caldera volcanoes include the symmetrical Sugarloaf Peak SSE of the caldera and Lakeshore Cone, a small cinder cone at the edge of Fenner Lake in the NE part of the caldera. Most documented eruptions have originated from Cerberus, although Coats (1950) considered that both Sugarloaf and Lakeshore Cone could have been recently active. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0cV9T4K0$ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o60WU3UmU$> Sheveluch | Central Kamchatka (Russia) | 56.653°N, 161.36°E | Summit elev. 3283 m KVERT reported that a thermal anomaly over Sheveluch was identified in satellite images during 11-18 February. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted. Geologic Summary. The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1300 km3 volcano is one of Kamchatka's largest and most active volcanic structures. The summit of roughly 65,000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera breached to the south. Many lava domes dot its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large horseshoe-shaped caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. At least 60 large eruptions have occurred during the Holocene, making it the most vigorous andesitic volcano of the Kuril-Kamchatka arc. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka. Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0UBwUFCI$ <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6hAjzHBM$> Suwanosejima | Ryukyu Islands (Japan) | 29.638°N, 129.714°E | Summit elev. 796 m JMA reported that 102 explosions were recorded at Suwanosejima's Ontake Crater during 14-21 February. The explosions produced ash plumes that rose as high as 1.8 km above the crater rim. Ashfall was reported in Toshima village (3.5 km SSW) during 14-18 February, and nighttime crater incandescence was visible during 18-21 February. The Alert Level remained at 3 and the public was warned to stay 2 km away from the crater. Geologic Summary. The 8-km-long, spindle-shaped island of Suwanosejima in the northern Ryukyu Islands consists of an andesitic stratovolcano with two historically active summit craters. The summit is truncated by a large breached crater extending to the sea on the east flank that was formed by edifice collapse. Suwanosejima, one of Japan's most frequently active volcanoes, was in a state of intermittent strombolian activity from Otake, the NE summit crater, that began in 1949 and lasted until 1996, after which periods of inactivity lengthened. The largest historical eruption took place in 1813-14, when thick scoria deposits blanketed residential areas, and the SW crater produced two lava flows that reached the western coast. At the end of the eruption the summit of Otake collapsed forming a large debris avalanche and creating the horseshoe-shaped Sakuchi caldera, which extends to the eastern coast. The island remained uninhabited for about 70 years after the 1813-1814 eruption. Lava flows reached the eastern coast of the island in 1884. Only about 50 people live on the island. Source: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0QO_k2QY$ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6QGyspRE$> Turrialba | Costa Rica | 10.025°N, 83.767°W | Summit elev. 3340 m OVSICORI-UNA reported that at 0412 on 19 February an eruption at Turrialbaâ??s Cráter Oeste produced a small ash plume that rose 100 m above the summit and drifted W. Minor ashfall was reported by park rangers in Parque Nacional Volcán Irazú. An eruptive event was recorded later that day at 1624, though weather clouds prevented visual confirmation. Geologic Summary. Turrialba, the easternmost of Costa Rica's Holocene volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano located across a broad saddle NE of Irazú volcano overlooking the city of Cartago. The massive edifice covers an area of 500 km2. Three well-defined craters occur at the upper SW end of a broad 800 x 2200 m summit depression that is breached to the NE. Most activity originated from the summit vent complex, but two pyroclastic cones are located on the SW flank. Five major explosive eruptions have occurred during the past 3500 years. A series of explosive eruptions during the 19th century were sometimes accompanied by pyroclastic flows. Fumarolic activity continues at the central and SW summit craters. Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA) https://urldefense.com/v3/__http://www.ovsicori.una.ac.cr/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0gFlwOMY$ <https://urldefense.com/v3/__http://www.ovsicori.una.ac.cr/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o66fNieE0$> Wolf | Isla Isabela (Galapagos) | 0.02°N, 91.35°W | Summit elev. 1710 m IG reported that the eruption at Wolf continued during 15-22 February. Daily thermal alert counts, as high as around 250, indicated active and advancing lava flows on the SE flank. Geologic Summary. Wolf, the highest volcano of the Galápagos Islands, straddles the equator at the north end of the archipelago's largest island, Isabela. The 1710-m-high edifice has steeper slopes than most other Isabela volcanoes, reaching angles up to 35 degrees. A 6 x 7 km caldera, at 700 m one of the deepest of the Galápagos Islands, is located at the summit. A prominent bench on the west side of the caldera rises 450 above the caldera floor, much of which is covered by a lava flow erupted in 1982. Radial fissures concentrated along diffuse rift zones extend down the north, NW, and SE flanks, and submarine vents lie beyond the north and NW fissures. Similar unvegetated flows originating from a circumferential chain of spatter and scoria cones on the eastern caldera rim drape the forested flanks to the sea. The proportion of aa lava flows at Volcán Wolf exceeds that of other Galápagos volcanoes. An eruption in in 1797 was the first documented historical eruption in the Galápagos Islands. Source: Instituto GeofÃsico-Escuela Politécnica Nacional (IG) https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0Pb6Ed_M$ <https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6--i3a_c$> Yasur | Vanuatu | 19.532°S, 169.447°E | Summit elev. 361 m The Wellington VAAC reported that on 17 and 19 February ash emissions from Yasur were intermittently visible in webcam and satellite images rising as high as 1.2 km (4,000 ft) a.s.l. and drifting SW. Geologic Summary. Yasur, the best-known and most frequently visited of the Vanuatu volcanoes, has been in more-or-less continuous Strombolian and Vulcanian activity since Captain Cook observed ash eruptions in 1774. This style of activity may have continued for the past 800 years. Located at the SE tip of Tanna Island, this mostly unvegetated pyroclastic cone has a nearly circular, 400-m-wide summit crater. The active cone is largely contained within the small Yenkahe caldera, and is the youngest of a group of Holocene volcanic centers constructed over the down-dropped NE flank of the Pleistocene Tukosmeru volcano. The Yenkahe horst is located within the Siwi ring fracture, a 4-km-wide, horseshoe-shaped caldera associated with eruption of the andesitic Siwi pyroclastic sequence. Active tectonism along the Yenkahe horst accompanying eruptions has raised Port Resolution harbor more than 20 m during the past century. Source: Wellington Volcanic Ash Advisory Center (VAAC) https://urldefense.com/v3/__http://vaac.metservice.com/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0IwRsTX8$ <https://urldefense.com/v3/__http://vaac.metservice.com/__;!!IKRxdwAv5BmarQ!MOJcIEJkRmRgNghrXURarbVwSrpVM9dyC7MntFCupFODNm-2A8g_Z5o6BWyG5u4$> 7-7-7-7-7-7-7-7-7-7-7-7-7-7 ============================================================== Volcano Listserv is a collaborative venture among Arizona State University (ASU), Portland State University (PSU), the Global Volcanism Program (GVP) of the Smithsonian Institution's National Museum of Natural History, and the International Association for Volcanology and Chemistry of the Earth's Interior (IAVCEI). ASU - http://www.asu.edu/ PSU - https://urldefense.com/v3/__http://pdx.edu/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0QYv6OWY$ GVP - https://urldefense.com/v3/__http://www.volcano.si.edu/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0aCoTkEM$ IAVCEI - https://urldefense.com/v3/__https://www.iavceivolcano.org/__;!!IKRxdwAv5BmarQ!MKdEtlZOSv0pFZdOOl9oEhYxfPb7cDDqCBIKmPK7Zl32AWCmcL8J__F0QJM39MA$ To unsubscribe from the volcano list, send the message: signoff volcano to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxx. To contribute to the volcano list, send your message to: volcano@xxxxxxx. Please do not send attachments. ============================================================== ------------------------------ End of Volcano Digest - 18 Feb 2022 to 23 Feb 2022 (#2022-24) *************************************************************
