4-4-4-4-4-4-4-4-4-4-4-4-4 From: "Kuhn, Sally" <KUHNS@xxxxxx> Smithsonian / USGS Weekly Volcanic Activity Report 26 February-4 March 2025 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!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWHg3kGO2g$> New Activity/Unrest: Atka Volcanic Complex, United States | Bezymianny, Russia | Etna, Italy | Lewotobi, Indonesia | Lewotolok, Indonesia | Poas, Costa Rica | Poas, Costa Rica | Telica, Nicaragua | Yakedake, Japan Ongoing Activity: Ahyi, United States | Aira, Japan | Ambae, Vanuatu | Ambrym, Vanuatu | Dukono, Indonesia | El Misti, Peru | Great Sitkin, United States | Huaynaputina, Peru | Ibu, Indonesia | Kaitoku Seamount, Japan | Kanlaon, Philippines | Karymsky, Russia | Kilauea, United States | Marapi, Indonesia | Merapi, Indonesia | Popocatepetl, Mexico | Sabancaya, Peru | Semeru, Indonesia | Sheveluch, Russia | Spurr, United States | Suwanosejima, Japan | Ubinas, Peru | 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 Atka Volcanic Complex | United States | 52.331°N, 174.139°W | Summit elev. 1518 m The Alaska Volcano Observatory (AVO) reported that no additional explosions at the Atka volcanic complex were detected after the small explosion recorded at 1926 on 20 February. Several small daily earthquakes were detected during 21 February-3 March, though at a decreasing frequency through the week; seismicity was characterized as low. No ash deposits from the February 20 explosive event were visible in clear satellite views. Webcam views showed occasional steam emissions throughout the week. At 1452 on 3 March 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 Atka Volcanic Complex consists of a central shield and Pleistocene caldera and four notable volcanic cones. A major explosive dacitic eruption accompanied formation of the caldera about 500,000 to 300,000 years ago; approximately half of the caldera rime remains, open towards the NW. The Sarichef cone, ~5 km ESE of the caldera rim, retains a symmetrical profile, unlike most other heavily eroded features outside the caldera to the S and W. The Kliuchef stratovolcano grew within the caldera and exhibits five eruptive vents striking NE, including two at the summit, that have been active in the Holocene. A 700-m-diameter crater 1 km NE of the summit may have been the source vent for a large 1812 CE eruption. Hot springs and fumaroles are located on the flanks of Kliuchef and in a glacial valley to the SW. The most frequently active volcano of the complex is Korovin, at the NE tip of Atka Island about 5 km N of Kliuchef. An 800-m-diameter crater on the SE side of the summit contains a deep circular pit that sometimes contains a crater lake thought to be the source of phreatic ash explosions. The smaller Konia cone, slightly offset to the E, lies between Kliuchef and Korovin. Most of the lava flows in the complex are basaltic, though some dacitic flows are also present. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://avo.alaska.edu/ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWE9zuHRzw$> Bezymianny | Russia | 55.972°N, 160.595°E | Summit elev. 2882 m The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that a strong thermal anomaly over Bezymianny was identified in satellite images during 20-28 February. According to the Institute of Volcanology and Seismology (IVS) of the Far Eastern Branch of the Russian Academy of Sciences (FEB RAS), incandescent debris avalanches descended the SE flanks and summit incandescence was visible during dark hours. Daily ash plumes generated from debris avalanches rose more than 2 km above the summit and drifted in multiple directions. Weather conditions sometimes obscured webcam and satellite views. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are reported in UTC; 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. Sources: 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!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWFpL_gjag$> ; Institute of Volcanology and Seismology (IVS) of the Far Eastern Branch of the Russian Academy of Sciences (FEB RAS) http://www.kscnet.ru/ivs/ <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWEDsRI3jg$> Etna | Italy | 37.748°N, 14.999°E | Summit elev. 3357 m The Sezione di Catania - Osservatorio Etneo (INGV) reported that an eruption at Etna continued during 24 February-2 March. Activity observed through webcams and during field inspections on 28 February and 2 March was characterized by the effusion of lava flows from at least four vents, Strombolian activity at the summit, and gas emissions at several of the summit craters. Strombolian activity at SE Crater stopped on 25 February and the effusion rate at the fissure on the upper S flank of Bocca Nuova Crater decreased significantly. On 27 February Strombolian activity resumed at SE Crater and lava effusion increased at Bocca Nuova Crater. Lava overflowed the SE Crater on 28 February. That same day several new features on the upper S flank of Bocca Nuova Crater were identified in drone images. Several small cracks partly surrounding a 150-m-long, oval depression, oriented NE-SW, was located just upflank of the eruptive fissure. At a higher elevation than the depression was a vent that produced a yellow fumarolic plume. Thermally anomalous areas were located about 100 m both to the E and W of the depression. The lava-flow fronts were most active at an elevation of 2,750 m. Strombolian activity at SE Crater ceased during the evening of 28 February. Lava effusion at the Bocca Nuova vent continued during 1-2 March at a low rate. Geologic Summary. Mount Etna, towering above Catania on the island of Sicily, has one of the world's longest documented records of volcanism, dating back to 1500 BCE. Historical lava flows of basaltic composition cover much of the surface of this massive volcano, whose edifice is the highest and most voluminous in Italy. The Mongibello stratovolcano, truncated by several small calderas, was constructed during the late Pleistocene and Holocene over an older shield volcano. The most prominent morphological feature of Etna is the Valle del Bove, a 5 x 10 km caldera open to the east. Two styles of eruptive activity typically occur, sometimes simultaneously. Persistent explosive eruptions, sometimes with minor lava emissions, take place from one or more summit craters. Flank vents, typically with higher effusion rates, are less frequently active and originate from fissures that open progressively downward from near the summit (usually accompanied by Strombolian eruptions at the upper end). Cinder cones are commonly constructed over the vents of lower-flank lava flows. Lava flows extend to the foot of the volcano on all sides and have reached the sea over a broad area on the SE flank. Source: Sezione di Catania - Osservatorio Etneo (INGV) http://www.ct.ingv.it/ <https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWH3cCWMaA$> Lewotobi | Indonesia | 8.542°S, 122.775°E | Summit elev. 1703 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity continued at Lewotobi Laki-laki. During 25 February-4 March. Dense gray ash plumes were observed multiple times on most days rising as high as 2.5 km above the summit; no emissions were observed on 4 March. The ash plumes drifted mainly NW, W, and SW, but sometimes N and NE. Incandescence at the summit and reflected in the plume was visible in several of the webcam images posted with the reports. A news article noted that the Frans Xavier Seda Airport (60 km W) was temporarily closed on 2 March due to impacts from ash. According to a news article about 250 families that had been in evacuation centers since November 2024 moved to temporary housing on 24 February, and the remaining families will move during the next relocation phase. The Alert Level remained at 3 (on a scale of 1-4) and the public was warned to stay 5 km away from the center of Laki-laki and 6 km in a semicircle clockwise from the SW to the NE. Geologic Summary. The Lewotobi edifice in eastern Flores Island is composed of the two adjacent Lewotobi Laki-laki and Lewotobi Perempuan stratovolcanoes (the "husband and wife"). Their summits are less than 2 km apart along a NW-SE line. The conical Laki-laki to the NW has been frequently active during the 19th and 20th centuries, while the taller and broader Perempuan has had observed eruptions in 1921 and 1935. Small lava domes have grown during the 20th century in both of the summit craters, which are open to the north. A prominent cone, Iliwokar, occurs on the E flank of Perampuan. Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWFlWWtbSw$> ; Antara News https://www.antaranews.com/berita/4667845/250-keluarga-korban-erupsi-lewotobi-pindah-ke-rumah-hunian-sementara <https://urldefense.com/v3/__https://www.antaranews.com/berita/4667845/250-keluarga-korban-erupsi-lewotobi-pindah-ke-rumah-hunian-sementara__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWGN65mgMg$> ; Antara News https://www.antaranews.com/berita/4683557/bandara-frans-seda-maumere-ditutup-dampak-erupsi-gunung-lewotobi <https://urldefense.com/v3/__https://www.antaranews.com/berita/4683557/bandara-frans-seda-maumere-ditutup-dampak-erupsi-gunung-lewotobi__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWHGrrbIIQ$> Lewotolok | Indonesia | 8.274°S, 123.508°E | Summit elev. 1431 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that an eruption at Lewotolok was ongoing during 25 February-4 March. Seismicity increased and was characterized by the emergence of harmonic tremor on 25 February and an increase in the number and intensity of earthquakes during 25-26 February. Tiltmeter data showed no deformation. White-and-gray ash plumes that were sometimes dense rose 200-700 m above the summit and drifted NW and W; eruptive events were recorded during 3-4 March though not visually confirmed. Incandescence at the summit was visible in webcam images and incandescent material was being ejected above the summit on most days. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 2 km away from the vent and 2.5 km away on the S, SE, and W flanks. 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) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWFlWWtbSw$> Poas | Costa Rica | 10.2°N, 84.233°W | Summit elev. 2697 m On 3 March the Observatorio Vulcanológico y Sismológico de Costa Rica-Universidad Nacional (OVSICORI-UNA) reported that over the previous few days small collapses occurred from the inner SW wall of Turrialbaâ??s West Crater, in the same area that is sometimes incandescent. Material from the collapses was mostly deposited inside the crater, though some ash rose above the rim. At 0933 a small ash eruption that lasted for 15 seconds produced an ash-and-gas plume that rose 100 m and drifted SW. No collapses were recorded on 4 March. Geologic Summary. The broad vegetated edifice of Poás, one of the most active volcanoes of Costa Rica, contains three craters along a N-S line. The frequently visited multi-hued summit crater lakes of the basaltic-to-dacitic volcano are easily accessible by vehicle from the nearby capital city of San José. A N-S-trending fissure cutting the complex stratovolcano extends to the lower N flank, where it has produced the Congo stratovolcano and several lake-filled maars. The southernmost of the two summit crater lakes, Botos, last erupted about 7,500 years ago. The more prominent geothermally heated northern lake, Laguna Caliente, is one of the world's most acidic natural lakes, with a pH of near zero. It has been the site of frequent phreatic and phreatomagmatic eruptions since an eruption was reported in 1828. Eruptions often include geyser-like ejections of crater-lake water. Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA) http://www.ovsicori.una.ac.cr/ <https://urldefense.com/v3/__http://www.ovsicori.una.ac.cr/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWGmcfpGiQ$> Poas | Costa Rica | 10.2°N, 84.233°W | Summit elev. 2697 m The Observatorio Vulcanológico y Sismológico de Costa Rica-Universidad Nacional (OVSICORI-UNA) reported that eruptive activity at Poás continued at variable levels during 21 February-4 March. Sulfur dioxide levels fluctuated at high levels. There were no eruptive events recorded during 21-22 February. Frequent small phreatic eruptions from Boca C were detected on 23 February at a rate of 5-20 per hour. Frequent small phreatic eruptions from both Boca A and Boca C continued during 25 February-4 March; the events produced plumes of steam and gas and ejected material to heights as high as 100 m above the surface of Laguna Caliente. According to a news article ashfall may have been reported as far as Sarchà (17 km SW) during 1-2 March, and a strong sulfur odor was reported in several areas near the volcano. Geologic Summary. The broad vegetated edifice of Poás, one of the most active volcanoes of Costa Rica, contains three craters along a N-S line. The frequently visited multi-hued summit crater lakes of the basaltic-to-dacitic volcano are easily accessible by vehicle from the nearby capital city of San José. A N-S-trending fissure cutting the complex stratovolcano extends to the lower N flank, where it has produced the Congo stratovolcano and several lake-filled maars. The southernmost of the two summit crater lakes, Botos, last erupted about 7,500 years ago. The more prominent geothermally heated northern lake, Laguna Caliente, is one of the world's most acidic natural lakes, with a pH of near zero. It has been the site of frequent phreatic and phreatomagmatic eruptions since an eruption was reported in 1828. Eruptions often include geyser-like ejections of crater-lake water. Sources: 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!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWGmcfpGiQ$> ; Tico Times https://ticotimes.net/2025/03/03/costa-rican-volcanoes-awaken-as-poas-and-turrialba-show-increased-activity <https://urldefense.com/v3/__https://ticotimes.net/2025/03/03/costa-rican-volcanoes-awaken-as-poas-and-turrialba-show-increased-activity__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWEpILH7Xw$> Telica | Nicaragua | 12.606°N, 86.84°W | Summit elev. 1036 m Based on webcam and satellite images, the Washington VAAC reported that at 0720 on 25 February a narrow plume from Telica, possibly containing ash, extended more than 11 km SW at an altitude of 1.2 km (4,000 ft) a.s.l. Geologic Summary. Telica, one of Nicaragua's most active volcanoes, has erupted frequently since the beginning of the Spanish era. This volcano group consists of several interlocking cones and vents with a general NW alignment. Sixteenth-century eruptions were reported at symmetrical Santa Clara volcano at the SW end of the group. However, its eroded and breached crater has been covered by forests throughout historical time, and these eruptions may have originated from Telica, whose upper slopes in contrast are unvegetated. The steep-sided cone of Telica is truncated by a 700-m-wide double crater; the southern crater, the source of recent eruptions, is 120 m deep. El Liston, immediately E, has several nested craters. The fumaroles and boiling mudpots of Hervideros de San Jacinto, SE of Telica, form a prominent geothermal area frequented by tourists, and geothermal exploration has occurred nearby. Source: Washington Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/messages.html <https://urldefense.com/v3/__http://www.ssd.noaa.gov/VAAC/messages.html__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWGL3r1m2g$> Yakedake | Japan | 36.227°N, 137.587°E | Summit elev. 2455 m The Japan Meteorological Agency (JMA) raised the Alert Level for Yakedake to 2 (on a scale of 1-5) at 0920 on 4 March, noting that the number of small volcanic earthquakes with epicenters near the summit began increasing around 1400 the day before. Additionally, inflation near the summit was detected in Global Navigation Satellite Systems (GNSS) data. JMA warned the public to be cautious within 1 km of the cater. Geologic Summary. Yakedake rises above the popular resort of Kamikochi in the Northern Japan Alps. The small dominantly andesitic stratovolcano, one of several Japanese volcanoes named Yakedake or Yakeyama ("Burning Peak" or "Burning Mountain"), was constructed astride a N-S-trending ridge between the older volcanoes of Warudaniyama and Shirataniyama. Akandanayama, about 4 km SSW, is a stratovolcano with lava domes that was active into the Holocene. A 300-m-wide crater is located at the summit, and explosion craters are found on the SE and N flanks. Frequent small-to-moderate phreatic eruptions have occurred during the 20th century. On 11 February 1995 a hydrothermal explosion in a geothermal area killed two people at a highway construction site. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWESvj0Tgg$> Ongoing Activity Ahyi | United States | 20.42°N, 145.03°E | Summit elev. -75 m Unrest at Ahyi Seamount continued during 21-28 February. Occasional weak signals coming from the direction of Ahyi were identified in data from underwater pressure sensors near Wake Island (about 2,270 km E of Ahyi). The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale) and the Volcano Alert Level remained at Advisory (the second lowest level on a four-level scale). Geologic Summary. Ahyi seamount is a large conical submarine volcano that rises to within 75 m of the ocean surface ~18 km SE of the island of Farallon de Pajaros in the northern Marianas. Water discoloration has been observed there, and in 1979 the crew of a fishing boat felt shocks over the summit area, followed by upwelling of sulfur-bearing water. On 24-25 April 2001 an explosive eruption was detected seismically by a station on Rangiroa Atoll, Tuamotu Archipelago. The event was well constrained (+/- 15 km) at a location near the southern base of Ahyi. An eruption in April-May 2014 was detected by NOAA divers, hydroacoustic sensors, and seismic stations. Source: US Geological Survey https://www.usgs.gov/ <https://urldefense.com/v3/__https://www.usgs.gov/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWFxxuXioA$> Aira | Japan | 31.5772°N, 130.6589°E | Summit elev. 1117 m The Japan Meteorological Agency (JMA) reported ongoing eruptive activity at Minamidake Crater (Aira Calderaâ??s Sakurajima volcano) during 24 February-2 March. Nightly crater incandescence was visible in webcam images. An explosion at 1924 on 24 February generated an ash plume that rose 600 m above the crater rim and drifted S, and ejected large blocks 500-700 m from the vent. On 26 February sulfur dioxide emissions were slightly higher than average at 1,500 tons per day. Eruptive events at 1037 on 27 February and at 1100 on 2 March produced ash plumes that rose 1-1.3 km above the crater rim and rose up and drifted NE, respectively. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to stay 1 km away from both craters. Geologic Summary. The Aira caldera in the northern half of Kagoshima Bay contains the post-caldera Sakurajima volcano, one of Japan's most active. Eruption of the voluminous Ito pyroclastic flow accompanied formation of the 17 x 23 km caldera about 22,000 years ago. The smaller Wakamiko caldera was formed during the early Holocene in the NE corner of the caldera, along with several post-caldera cones. The construction of Sakurajima began about 13,000 years ago on the southern rim and built an island that was joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kitadake summit cone ended about 4,850 years ago, after which eruptions took place at Minamidake. Frequent eruptions since the 8th century have deposited ash on the city of Kagoshima, located across Kagoshima Bay only 8 km from the summit. The largest recorded eruption took place during 1471-76. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWESvj0Tgg$> Ambae | Vanuatu | 15.389°S, 167.835°E | Summit elev. 1496 m On 27 February the Vanuatu Meteorology and Geohazards Department (VMGD) reported that steam and/or gas emissions from the active vents at Ambae were ongoing during February based on satellite images and webcam images during 18 and 20-21 February. Seismic data also confirmed ongoing unrest. 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 with numerous 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. Source: Vanuatu Meteorology and Geohazards Department (VMGD) http://www.geohazards.gov.vu/ <https://urldefense.com/v3/__http://www.geohazards.gov.vu/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWHnD9yPYA$> Ambrym | Vanuatu | 16.25°S, 168.12°E | Summit elev. 1334 m On 27 February the Vanuatu Meteorology and Geohazards Department (VMGD) reported ongoing fumarolic activity at Ambrym from both Benbow and Marum craters based on webcam images. Seismic data confirmed ongoing unrest. A low-level thermal anomaly was identified in satellite data from 11 February indicting increased surface temperatures. The Alert Level remained at 2 (on a scale of 0-5). VMGD warned the public to stay outside of Permanent Danger Zone A, defined as a 1-km radius around Benbow Crater and a 2-km radius around Marum Crater, and to stay 500 m away from the ground cracks created by the December 2018 eruption. Geologic Summary. Ambrym, a large basaltic volcano with a 12-km-wide caldera, is one of the most active volcanoes of the New Hebrides Arc. A thick, almost exclusively pyroclastic sequence, initially dacitic then basaltic, overlies lava flows of a pre-caldera shield volcano. The caldera was formed during a major Plinian eruption with dacitic pyroclastic flows about 1,900 years ago. Post-caldera eruptions, primarily from Marum and Benbow cones, have partially filled the caldera floor and produced lava flows that ponded on the floor or overflowed through gaps in the caldera rim. Post-caldera eruptions have also formed a series of scoria cones and maars along a fissure system oriented ENE-WSW. Eruptions have apparently occurred almost yearly during historical time from cones within the caldera or from flank vents. However, from 1850 to 1950, reporting was mostly limited to extra-caldera eruptions that would have affected local populations. Source: Vanuatu Meteorology and Geohazards Department (VMGD) http://www.geohazards.gov.vu/ <https://urldefense.com/v3/__http://www.geohazards.gov.vu/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWHnD9yPYA$> Dukono | Indonesia | 1.6992°N, 127.8783°E | Summit elev. 1273 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that the eruption at Dukono was ongoing during 26 February-4 March. White plumes rose 100-200 m above the crater rim and drifted W on 26 February. Daily white-and-gray ash plumes that were often dense rose as high as 2.5 km above the crater rim and drifted in multiple directions during the rest of the week. Booming sounds were reported during 28 February and 2-3 March. The Alert Level remained at Level 2 (on a scale of 1-4) and the public was warned to stay 4 km away from the Malupang Warirang Crater. 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!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWFlWWtbSw$> El Misti | Peru | 16.294°S, 71.409°W | Summit elev. 5822 m The Instituto GeofÃsico del Perú (IGP) reported that three lahars carrying blocks traveled down El Mistiâ??s flanks during 27-28 February. The first descended the Matagente drainage on the NW flank at 1655 on 27 February, the second descended the Huarangal-Los Incas drainage on the SW flank at 1725 on 27 February, and the third descended the SE flank in the Agua Salada, the Peña Colorada, or a nearby drainage at 1725 on 28 February. The public was warned to stay away from drainages, roads, and bridges on the flanks where there had been lahars. The Alert Level remained at Green (the lowest level on a four-color scale). Geologic Summary. El Misti is a symmetrical andesitic stratovolcano with nested summit craters that towers above the city of Arequipa, Peru. The modern symmetrical cone, constructed within a small 1.5 x 2 km wide summit caldera that formed between about 13,700 and 11,300 years ago, caps older Pleistocene volcanoes that underwent caldera collapse about 50,000 years ago. A large scoria cone has grown with the 830-m-wide outer summit crater. At least 20 tephra-fall deposits and numerous pyroclastic-flow deposits have been documented during the past 50,000 years, including a pyroclastic flow that traveled 12 km to the south about 2000 years ago. The most recent activity has been dominantly pyroclastic, and strong winds have formed a parabolic dune field of volcanic ash extending up to 20 km downwind. An eruption in the 15th century affected nearby Inca inhabitants. Some reports of historical eruptions may represent increased fumarolic activity. Source: Instituto GeofÃsico del Perú (IGP) http://www.igp.gob.pe/ <https://urldefense.com/v3/__http://www.igp.gob.pe/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWHZ-PL0gg$> Great Sitkin | United States | 52.076°N, 176.13°W | Summit elev. 1740 m The Alaska Volcano Observatory (AVO) reported that slow lava effusion continued to feed a thick flow in Great Sitkinâ??s summit crater, confirmed by a 26 February radar image. Small daily earthquakes were detected by the seismic network. Slightly elevated surface temperatures were observed in satellite data during 25-26 February and 28 February-1 March and typical minor steaming from the vent region was visible in webcam images on most days during the week. Weather clouds sometimes obscured views of the volcano. 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!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWE9zuHRzw$> Huaynaputina | Peru | 16.6144°S, 70.8542°W | Summit elev. 4679 m The Instituto GeofÃsico del Perú (IGP) reported that a lahar carrying blocks descended the El Volcán drainage, on the S flank of Huaynaputina, at 1825 on 2 March. The public was warned to stay away from the drainage and to be cautious when traveling along the Quinistaquillas-Sijuaya highway. Geologic Summary. Huaynaputina (whose name means "new volcano") was the source of the largest historical eruption of South America in 1600 CE. It has no prominent topographic expression and lies within a 2.5-km-wide collapse depression and further excavated by glaciers within a Tertiary to Pleistocene edifice. Three overlapping ash cones with craters up to 100 m deep were constructed during the 1600 CE eruption on the floor of the older crater, whose outer flanks are heavily mantled by ash deposits from the 1600 eruption. This powerful fissure-fed eruption may have produced nearly 30 km3 of dacitic tephra, including pyroclastic flows and surges that traveled 13 km to the E and SE. Lahars reached the Pacific Ocean, 120 km away. The eruption caused substantial damage to the major cities of Arequipa and Moquengua. Source: Instituto GeofÃsico del Perú (IGP) http://www.igp.gob.pe/ <https://urldefense.com/v3/__http://www.igp.gob.pe/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWHZ-PL0gg$> Ibu | Indonesia | 1.488°N, 127.63°E | Summit elev. 1325 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that the eruption at Ibu continued during 19-25 February. Multiple daily gray, white-and-gray, or gray-to-brown ash plumes that were often dense rose as high as 1.5 km above the summit and drifted in multiple directions. Incandescence at the summit was visible in some webcam images posted with the reports. 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!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWFlWWtbSw$> Kaitoku Seamount | Japan | 26.1217°N, 141.0955°E | Summit elev. -95 m The Japan Meteorological Agency (JMA) reported that no signs of eruptive activity at the Kaitoku Seamount have been observed since discolored water and floating material were identified in January 2023. At 1100 on 14 February the â??eruption warningâ?? status was lowered to â??eruption forecastâ?? based on a two-level scale used for underwater volcanoes. Geologic Summary. Submarine eruption have been observed during March 1984 and August 2022-January 2023 from Kaitoku Seamount (Kaitoku Kaizan), a three-peaked submarine volcano 80 km NNW of Kita-Ioto. The type of activity related to other observations of discolored water or bubbling, including an observation from 1543 CE, is uncertain. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWESvj0Tgg$> Kanlaon | Philippines | 10.4096°N, 123.13°E | Summit elev. 2422 m The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported continuing eruptive activity at Kanlaon during 25 February-3 March. The seismic network recorded 3-10 daily volcanic earthquakes, though on 28 February there were 24 volcanic earthquakes along with three periods of volcanic tremor lasting from three minutes to two hours and 13 minutes. Average daily sulfur dioxide emissions ranged from 1,118 to 2,527 tonnes per day. Gas-and-steam emissions that were sometimes diffuse rose generally as high as 100 m above the summit and drifted W, SW, and SSW; weather conditions obscured views during 2-3 March. On 28 February three periods of ash emissions corresponding to the periods of volcanic tremor produced gas-and-ash plumes that rose as high as 150 m above the summit and drifted SW and WSW. According to the Office of Civil Defense and news reports more than 8,500 people remained in evacuation shelters, noting that 36 families from La Castellana (16 km SW) and 48 families from Canlaon City (10 km ESE) will not be able to return to their homes within the 4-km permanent danger zone. The Alert Level remained at 3 (on a scale of 0-5); the public was warned to stay 6 km away from the summit and pilots were warned not to fly close to the volcano. 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. Sources: Philippine Institute of Volcanology and Seismology (PHIVOLCS) http://www.phivolcs.dost.gov.ph/ <https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWEHLs1UkA$> ; Office of Civil Defense https://www.ocd.gov.ph/index.php <https://urldefense.com/v3/__https://www.ocd.gov.ph/index.php__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWG0ieqHsQ$> ; Inquirer.net https://newsinfo.inquirer.net/2039728/ocd-permanent-kanlaon-evacuation-sites-to-cost-p1-billion?fbclid=IwY2xjawIyqLdleHRuA2FlbQIxMQABHdnLkVX6PGIx_Rj0My-8S3LMNN6vE1rZc68lJ-sJM49zzpcn3m63c5ggcw_aem_eZ1uFbi4mh7FFeszv1Lt-Q <https://urldefense.com/v3/__https://newsinfo.inquirer.net/2039728/ocd-permanent-kanlaon-evacuation-sites-to-cost-p1-billion?fbclid=IwY2xjawIyqLdleHRuA2FlbQIxMQABHdnLkVX6PGIx_Rj0My-8S3LMNN6vE1rZc68lJ-sJM49zzpcn3m63c5ggcw_aem_eZ1uFbi4mh7FFeszv1Lt-Q__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWFH_wxshw$> Karymsky | Russia | 54.049°N, 159.443°E | Summit elev. 1513 m The Kamchatkan Volcanic Eruption Response Team (KVERT) reported moderate levels of activity at Karymsky during 21-28 February. Thermal anomalies over the volcano were identified in satellite images during 22 and 25-26 February; weather clouds obscured views on the other days. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted. Geologic Summary. Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed during the early Holocene. The caldera cuts the south side of the Pleistocene Dvor volcano and is located outside the north margin of the large mid-Pleistocene Polovinka caldera, which contains the smaller Akademia Nauk and Odnoboky calderas. Most seismicity preceding Karymsky eruptions originated beneath Akademia Nauk caldera, located immediately south. The caldera enclosing Karymsky formed about 7600-7700 radiocarbon years ago; construction of the stratovolcano began about 2000 years later. The latest eruptive period began about 500 years ago, following a 2300-year quiescence. Much of the cone is mantled by lava flows less than 200 years old. Historical eruptions have been vulcanian or vulcanian-strombolian with moderate explosive activity and occasional lava flows from the summit crater. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWFpL_gjag$> Kilauea | United States | 19.421°N, 155.287°W | Summit elev. 1222 m The Hawaiian Volcano Observatory (HVO) reported that the eruption within Kilaueaâ??s Kaluapele summit caldera, from vents along the SW margin of Halemaâ??umaâ??u Crater, continued at variable levels during 26 February-4 March. The eleventh episode of lava fountaining occurred over an almost 13-hour period during 25-26 February. The episode was preceded by the appearance of incandescence from the row of vents along a fissure on the E side of the crater formed during September 2023. The incandescence began at one cone on the evening of 24 February and became visible along the entire fissure around 1800 on 25 February. The N vent began erupting at 1822 with low lava fountains, followed by small spattering fountains at the S vent just before 1900. Incandescence along the fissure persisted through much of the night, suggesting that magma may have intruded into the molten interior of Halemaâ??umaâ??u Crater prior to the onset of the episode. Lava fountaining from the N and S vents ceased by 0706 on 26 February. Lava covered approximately 75-80 percent of the crater floor and flowed onto the down-dropped block, around the September 2023 vents. A large amount of pumice, Pele?s hair, and lightweight reticulite blanketed the W rim of Halemaâ??umaâ??u Crater, and a few lightweight "ribbon" bombs up to about 0.6 m in diameter were deposited on top of the pumice. On 26 February fresh lava in the NE corner of the crater floor appeared to have been emplaced from beneath the crater floor rather than from the recent flows. That flow and several other small flows were related to the incandescence along the September 2023 fissure. Overnight during 26-27 February a large section of the lava-flow crust overturned in the middle of the crater floor and a few small lava breakouts occurred from the flow front in the SE corner of the crater floor. During 28 February-3 March flows S of the September 2023 vents were active. The flows at the NE part of the crater floor began to stagnate, with only spots of incandescence visible during 1-3 March. Incandescence at both the N and S vents was variable through 3 March. Small domed fountains less than 5 m high erupted from the S vent during 0730-0740 on 4 March, producing a slow-moving lava flow that advanced onto the crater floor. Small fountains at the N vent began at 0804; during 0933-0945 lava overflowed the vent. The S vent produced small fountains and an active lava flow during 1245-1400. Lava fountains began again at the N vent at around 1400 that rose 5-10 m, and by 1420 they were reaching 50 m. 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. 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://volcanoes.usgs.gov/observatories/hvo/ <https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWF6ue5fQQ$> Marapi | Indonesia | 0.38°S, 100.474°E | Summit elev. 2885 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Marapi continued during 26 Febraury-4 March. Eruptive events were recorded at 1430 on 1 March and at 0833 on 5 March, though no emissions were visually observed due to weather clouds. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 3 km away from the active crater. Geologic Summary. Gunung Marapi, not to be confused with the better-known Merapi volcano on Java, is Sumatra's most active volcano. This massive complex stratovolcano rises 2,000 m above the Bukittinggi Plain in the Padang Highlands. A broad summit contains multiple partially overlapping summit craters constructed within the small 1.4-km-wide Bancah caldera. The summit craters are located along an ENE-WSW line, with volcanism migrating to the west. More than 50 eruptions, typically consisting of small-to-moderate explosive activity, have been recorded since the end of the 18th century; no lava flows outside the summit craters have been reported in historical time. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWFlWWtbSw$> Merapi | Indonesia | 7.54°S, 110.446°E | Summit elev. 2910 m The Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG) reported that the eruption at Merapi (on Java) continued during 21-27 February. Seismicity was at higher levels that the previous week. The SW lava dome produced 53 lava avalanches that traveled as far as 2 km SW down the Bebeng drainage, 48 that traveled as far as 2 km SW down the Krasak drainage, 82 that traveled as far as 1.6 km SW down the Sat/Putih drainage, and one that descended the Boyong drainage on the S flank as far as 1.6 km. Morphological changes to the SW lava dome resulting from continuing effusion and collapses of material. 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!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWH7RTf7eg$> Popocatepetl | Mexico | 19.023°N, 98.622°W | Summit elev. 5393 m The Centro Nacional de Prevención de Desastres (CENAPRED) reported that eruptive activity continued at Popocatépetl during 25 February-4 March. The seismic network recorded 11-31 long-period events per day on most days, accompanied by steam-and-gas emissions; there were 143 such events during 2-3 March. The seismic network also recorded daily tremor, often characterized as low-amplitude harmonic tremor, with periods lasting 34 minutes to as long as two hours and 23 minutes. One volcano-tectonic was detected during 28 February-1 March, and 17 minutes of high-frequency tremor were detected during 1-2 March. According to the Washington VAAC ash plumes were visible in webcam images on 25 and 27 February rising 5.8-6.4 km (19,000-21,000 ft) a.s.l. (around 1 km above the summit) and drifting SE. The Alert Level remained at Yellow, Phase Two (the middle level on a three-color scale) and the public was warned to stay 12 km away from the crater. Geologic Summary. Volcán Popocatépetl, whose name is the Aztec word for smoking mountain, rises 70 km SE of Mexico City to form North America's 2nd-highest volcano. The glacier-clad stratovolcano contains a steep-walled, 400 x 600 m wide crater. The generally symmetrical volcano is modified by the sharp-peaked Ventorrillo on the NW, a remnant of an earlier volcano. At least three previous major cones were destroyed by gravitational failure during the Pleistocene, producing massive debris-avalanche deposits covering broad areas to the south. The modern volcano was constructed south of the late-Pleistocene to Holocene El Fraile cone. Three major Plinian eruptions, the most recent of which took place about 800 CE, have occurred since the mid-Holocene, accompanied by pyroclastic flows and voluminous lahars that swept basins below the volcano. Frequent historical eruptions, first recorded in Aztec codices, have occurred since Pre-Columbian time. Sources: Centro Nacional de Prevencion de Desastres (CENAPRED) https://www.gob.mx/cenapred <https://urldefense.com/v3/__https://www.gob.mx/cenapred__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWEtwrTtkw$> ; Washington Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/messages.html <https://urldefense.com/v3/__http://www.ssd.noaa.gov/VAAC/messages.html__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWGL3r1m2g$> Sabancaya | Peru | 15.787°S, 71.857°W | Summit elev. 5960 m The Instituto GeofÃsico del Perú (IGP) reported no explosions, thermal anomalies, or significant deformation at Sabancaya during 24 February-2 March. Gas-and-steam plumes rose as high as 700 m above the summit and drifted W, SW, and NW. Sulfur dioxide emissions were at moderate levels, averaging 216 tons per day. The Alert Level remained at Orange (the third level on a four-color scale) and the public was warned to stay outside of a 12 km radius from the summit. Geologic Summary. Sabancaya, located in the saddle NE of Ampato and SE of Hualca Hualca volcanoes, is the youngest of these volcanic centers and the only one to have erupted in historical time. The oldest of the three, Nevado Hualca Hualca, is of probable late-Pliocene to early Pleistocene age. The name Sabancaya (meaning "tongue of fire" in the Quechua language) first appeared in records in 1595 CE, suggesting activity prior to that date. Holocene activity has consisted of Plinian eruptions followed by emission of voluminous andesitic and dacitic lava flows, which form an extensive apron around the volcano on all sides but the south. Records of observed eruptions date back to 1750 CE. Source: Instituto GeofÃsico del Perú (IGP) http://www.igp.gob.pe/ <https://urldefense.com/v3/__http://www.igp.gob.pe/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWHZ-PL0gg$> Semeru | Indonesia | 8.108°S, 112.922°E | Summit elev. 3657 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity continued at Semeru during 26 February-4 March, with daily eruptive events recorded by the seismic network. Daily white-and-gray or gray ash plumes rose 400-1,300 m above the summit and drifted in multiple directions. 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!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWFlWWtbSw$> Sheveluch | Russia | 56.653°N, 161.36°E | Summit elev. 3283 m The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that lava extrusion may have continued at Sheveluchâ??s â??300 years of RASâ?? dome on the SW flank of Old Sheveluch and at the Young Sheveluch dome during 20-28 February. Daily thermal anomalies over the domes were identified in satellite images. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted. Geologic Summary. The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1,300 km3 andesitic volcano is one of Kamchatka's largest and most active volcanic structures, with at least 60 large eruptions during the Holocene. The summit of roughly 65,000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera breached to the south. Many lava domes occur on its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large open caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka. Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWFpL_gjag$> Spurr | United States | 61.299°N, 152.251°W | Summit elev. 3374 m On 28 February the Alaska Volcano Observatory (AVO) reported that ongoing unrest at Spurr was characterized by elevated seismicity and continuing deformation. Seismicity remained elevated, though had slightly decreased during the past few days. The seismic network recorded over 70 earthquakes with most located beneath the summit and some located beneath Crater Peak. Inflation continued at a similar rate that has been occurring since early 2024. Minor steam emissions were sometimes observed in webcam images. Weather clouds mostly obscured satellite and webcam views during 1-3 March. The Volcano Alert Level remained at Advisory (the second lowest level on a four-level scale) and the Aviation Color Code remained at Yellow (the second lowest level on a four-color scale). Geologic Summary. Mount Spurr is the closest volcano to Anchorage, Alaska (130 km W) and just NE of Chakachamna Lake. The summit is a large lava dome at the center of a roughly 5-km-wide amphitheater open to the south formed by a late-Pleistocene or early Holocene debris avalanche and associated pyroclastic flows that destroyed an older edifice. The debris avalanche traveled more than 25 km SE, and the resulting deposit contains blocks as large as 100 m in diameter. Several ice-carved post-collapse cones or lava domes are present. The youngest vent, Crater Peak, formed at the southern end of the amphitheater and has been the source of about 40 identified Holocene tephra layers. Eruptions from Crater Peak in 1953 and 1992 deposited ash in Anchorage. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://avo.alaska.edu/ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWE9zuHRzw$> Suwanosejima | Japan | 29.638°N, 129.714°E | Summit elev. 796 m The Japan Meteorological Agency (JMA) reported that eruptive activity at Suwanosejima's Ontake Crater continued during 24 February-3 March. Incandescence was observed nightly in webcam images. An explosion at 0601 on 24 February generated an ash plume that rose 900 m above the crater rim and drifted SE. An eruptive event at 1840 on 25 February generated an ash plume that rose 1.2 km above the summit. The Alert Level remained at 2 (the second level on a five-level scale) and the public was warned to stay at least 1.5 km away from the crater. Geologic Summary. The 8-km-long island of Suwanosejima in the northern Ryukyu Islands consists of an andesitic stratovolcano with two active summit craters. The summit is truncated by a large breached crater extending to the sea on the E flank that was formed by edifice collapse. One of Japan's most frequently active volcanoes, it was in a state of intermittent Strombolian activity from Otake, the NE summit crater, between 1949 and 1996, after which periods of inactivity lengthened. The largest recorded eruption took place in 1813-14, when thick scoria deposits covered residential areas, and the SW crater produced two lava flows that reached the western coast. At the end of the eruption the summit of Otake collapsed, forming a large debris avalanche and creating an open collapse scarp extending to the eastern coast. The island remained uninhabited for about 70 years after the 1813-1814 eruption. Lava flows reached the eastern coast of the island in 1884. Only about 50 people live on the island. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWESvj0Tgg$> Ubinas | Peru | 16.345°S, 70.8972°W | Summit elev. 5608 m The Instituto GeofÃsico del Perú (IGP) reported that a lahar carrying blocks descended the Volcánmayo drainage on the SE flank of Ubinas at 1727 on 26 February. The public was warned to stay away from the drainage and to avoid driving on the Querapi-Ubinas-Huarina highway. The Alert Level remained at Yellow (the second level on a four-color scale) and the public was warned to stay 2 km away from the crater. Geologic Summary. The truncated appearance of Ubinas, Perú's most active volcano, is a result of a 1.4-km-wide crater at the summit. It is the northernmost of three young volcanoes located along a regional structural lineament about 50 km behind the main volcanic front. The growth and destruction of Ubinas I was followed by construction of Ubinas II beginning in the mid-Pleistocene. The upper slopes of the andesitic-to-rhyolitic Ubinas II stratovolcano are composed primarily of andesitic and trachyandesitic lava flows and steepen to nearly 45°. The steep-walled, 150-m-deep summit crater contains an ash cone with a 500-m-wide funnel-shaped vent that is 200 m deep. Debris-avalanche deposits from the collapse of the SE flank about 3,700 years ago extend 10 km from the volcano. Widespread Plinian pumice-fall deposits include one from about 1,000 years ago. Holocene lava flows are visible on the flanks, but activity documented since the 16th century has consisted of intermittent minor-to-moderate explosive eruptions. Source: Instituto GeofÃsico del Perú (IGP) http://www.igp.gob.pe/ <https://urldefense.com/v3/__http://www.igp.gob.pe/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWHZ-PL0gg$> Yasur | Vanuatu | 19.532°S, 169.447°E | Summit elev. 361 m On 27 February the Vanuatu Meteorology and Geohazards Department (VMGD) reported that activity at Yasur continued at a level of â??major unrest,â?? as defined by the Alert Level 2 status (on a scale of 0-5). Satellite and webcam images indicated that explosions continued, producing emissions of gas, steam, and/or ash. Gas emissions were identified in satellite images, and seismic data confirmed continuing volcanic activity with explosions that were occasionally strong. Low-level thermal anomalies were identified in satellite images during 12-13 and 16 February. The report warned that ejected material from explosions could fall in and around the crater. The public was reminded to not enter the restricted area within 600 m around the boundaries of the Permanent Exclusion Zone, defined by Danger Zone A on the hazard map. Geologic Summary. Yasur has exhibited essentially continuous Strombolian and Vulcanian activity at least since Captain Cook observed ash eruptions in 1774. This style of activity may have continued for the past 800 years. Located at the SE tip of Tanna Island in Vanuatu, this pyroclastic cone has a nearly circular, 400-m-wide summit crater. The active cone is largely contained within the small Yenkahe caldera, and is the youngest of a group of Holocene volcanic centers constructed over the down-dropped NE flank of the Pleistocene Tukosmeru volcano. The Yenkahe horst is located within the Siwi ring fracture, a 4-km-wide open feature associated with eruption of the andesitic Siwi pyroclastic sequence. Active tectonism along the Yenkahe horst accompanying eruptions has raised Port Resolution harbor more than 20 m during the past century. Source: Vanuatu Meteorology and Geohazards Department (VMGD) http://www.geohazards.gov.vu/ <https://urldefense.com/v3/__http://www.geohazards.gov.vu/__;!!IKRxdwAv5BmarQ!cR9lmI214MyTjJOjs0XpVKR_Av29F65uUw6A9Dbiri159kyhiC1btMGEcy6C-ZuvRtlZzx8K3hzTZVpVQWHnD9yPYA$> 4-4-4-4-4-4-4-4-4-4-4-4-4 ============================================================== Volcano Listserv is a collaborative venture among Arizona State University (ASU), Portland State University (PSU), the Global Volcanism Program (GVP) of the Smithsonian Institution's National Museum of Natural History, and the International Association for Volcanology and Chemistry of the Earth's Interior (IAVCEI). 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