1-1-1-1-1-1-1-1-1-1-1-1-1-1 From: "Kuhn, Sally" <KUHNS@xxxxxx> Smithsonian / USGS Weekly Volcanic Activity Report 5-11 February 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!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH80nYqWqA$> New Activity/Unrest: Bezymianny, Russia | Dempo, Indonesia | Etna, Italy | Home Reef, Tonga | Kilauea, United States | Purace, Colombia | Spurr, United States Ongoing Activity: Ahyi, United States | Aira, Japan | Dukono, Indonesia | El Misti, Peru | Fuego, Guatemala | Gamalama, Indonesia | Great Sitkin, United States | Ibu, Indonesia | Kanlaon, Philippines | Karymsky, Russia | Lewotobi, Indonesia | Marapi, Indonesia | Merapi, Indonesia | Nevado del Ruiz, Colombia | Nyamulagira, DR Congo | Reventador, Ecuador | Sangay, Ecuador | Santa Maria, Guatemala | Semeru, Indonesia | Sheveluch, Russia | Suwanosejima, Japan | Ubinas, Peru | Whakaari/White Island, New Zealand The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday, these reports are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of all of Earth's volcanoes erupting during the week, but rather a summary of activity at volcanoes that meet criteria discussed in detail in the "Criteria and Disclaimers" section. Carefully reviewed, detailed reports about recent activity are published in issues of the Bulletin of the Global Volcanism Network. Note that many news agencies do not archive the articles they post on the Internet, and therefore the links to some sources may not be active. To obtain information about the cited articles that are no longer available on the Internet contact the source. New Activity/Unrest Bezymianny | Russia | 55.972°N, 160.595°E | Summit elev. 2882 m The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that a large thermal anomaly over Bezymianny was identified in satellite images during 1-6 February. A gas-and-steam plume drifted 13 km SW on 6 February. 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. 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!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH9hsQPbBw$> Dempo | Indonesia | 4.016°S, 103.121°E | Summit elev. 3142 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that an eruptive event at Dempo was recorded at 0952 on 2 February and lasted 27 seconds. A white plume rose about 50 m above the summit and drifted N. The Alert Level remained at 2 (on a scale of 1-4), and the public were reminded to stay 1 km away from the crater and as far as 2 km on the N flank. Geologic Summary. Dempo is a stratovolcano that rises above the Pasumah Plain of SE Sumatra. The andesitic complex has two main peaks, Gunung Dempo and Gunung Marapi, constructed near the SE rim of a 3-km-wide amphitheater open to the north. The high point of the older Gunung Dempo crater rim is slightly lower, and lies at the SE end of the summit complex. The taller Marapi cone was constructed within the older crater. Remnants of seven craters are found at or near the summit, with volcanism migrating WNW over time. The active 750 x 1,100 m active crater cuts the NW side of the Marapi cone and contains a 400-m-wide lake at the far NW end. Eruptions recorded since 1817 have been small-to-moderate explosions that produced local ashfall. 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!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH-IAyWlgg$> Etna | Italy | 37.748°N, 14.999°E | Summit elev. 3357 m Sezione di Catania - Osservatorio Etneo (INGV) reported that a new eruption began at Etna on 6 February. Explosive Strombolian activity began at a vent located in the W part of SE Crater. On 8 February a fissure opened at the base of Bocca Nuova Crater at an elevation of around 3,050 m and produced a lava flow that traveled SW towards Mt. Frumento Supino. The first observations through the webcam occurred at 1835, though weather conditions obscured views before that time so there was a possibility that effusion started a few hours earlier. Strombolian activity persisted at SE Crater. The Aviation Color Code was raised to Yellow (the second lowest level on a four-color scale) at 2004 and then to Orange at 2019. By 11 February the lava flow was about 2.6 km long and had reached an elevation of 2,600 m. The Aviation Color Code was raised to Red, the highest level, at 1030 on 12 February because of strong explosive activity at the summit craters. 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!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH_xY5KgAQ$> Home Reef | Tonga | 18.992°S, 174.775°W | Summit elev. -10 m On 7 February the Tonga Geological Services reported that analysis of satellite images showed no size changes, and no new lava flows at Home Reef. Thermal activity declined, with the last thermal anomaly identified on 25 January. That same day a series of plumes rose from the vent that were ash-rich near the base and mostly comprised of gas and steam at higher levels. Discolored water to the SW was visible. A new explosive vent, about 20 m in diameter, was located slightly W of the vent that produced lava flows. Ash deposits surrounded the vent and extended W and NW to the shoreline. Discolored water in the vicinity of the island was identified in a satellite image from 1 February. The Maritime Alert Level remained at Orange (the third level on a four-level scale), and mariners were advised to stay at least 2 nautical miles (3.7 km) away from the island. The Aviation Color Code remained at Yellow (the second level on a four-level scale), and the Alert Level for residents of Vavaâ??u and Haâ??apai remained at Green (the first level on a four-level scale). Geologic Summary. Home Reef, a submarine volcano midway between Metis Shoal and Late Island in the central Tonga islands, was first reported active in the mid-19th century, when an ephemeral island formed. An eruption in 1984 produced a 12-km-high eruption plume, large amounts of floating pumice, and an ephemeral 500 x 1,500 m island, with cliffs 30-50 m high that enclosed a water-filled crater. In 2006 an island-forming eruption produced widespread dacitic pumice rafts that drifted as far as Australia. Another island was built during a September-October 2022 eruption. Source: Tonga Geological Services, Government of Tonga https://www.facebook.com/tongageologicalservice <https://urldefense.com/v3/__https://www.facebook.com/tongageologicalservice__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH_76YP4nQ$> 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 paused on 4 February. Lava flows and fountaining at the N vent ceased at 1907 on 4 February and activity at the S vent ceased at 1923. Small areas of incandescence from the cooling lava on the crater floor and at the N vent were visible during 4-10 February. Gas emissions rose from the N vent. Incandescence at the N vent intensified overnight during 9-10 February and bursts of spatter were occasionally seen in webcam images on 10 February. The spattering intensified overnight during 10-11 February. Lava fountaining at the N vent began at 1016 on 11 February and by 1045 the fountains were 100 m high. Lava flowed onto the crater floor covering about a quarter of the surface. Slow lava effusion began at the S vent at around 1050. 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!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH88QQ1dvA$> Purace | Colombia | 2.3095°N, 76.3948°W | Summit elev. 4650 m The Servicio Geologico Colombiano (SGC) reported that seismicity at Puracé was stable during 4-10 February with no significant variations in both the number and magnitude of events. Earthquakes indicating rock fracturing had a maximum magnitude of 1.1 and were mainly located under Puracé cone, and to a less extent under Piocollo cone, at depths of 1-3 km. Earthquakes indicating fluid movement were located at depths less than 1 km beneath Puracé cone. Sulfur dioxide emissions were above background levels and deformation was occurring between the cones of Puracé, Piocollo, and Curiquinga. Fumarolic plumes rose from the vents on the outer flank of Puracé cone, and from a system of vents and cracks that extended between the Curiquinga and Piocollo cones. The Alert Level remained at Yellow (the second lowest level on a four-color scale). Geologic Summary. Puracé is an active andesitic volcano with a 600-m-diameter summit crater at the NW end of the Los Coconucos Volcanic Chain. This volcanic complex includes nine composite and five monogenetic volcanoes, extending from the Puracé crater more than 6 km SE to the summit of Pan de Azúcar stratovolcano. The dacitic massif which the complex is built on extends about 13 km NW-SE and 10 km NE-SW. Frequent small to moderate explosive eruptions reported since 1816 CE have modified the morphology of the summit crater, with the largest eruptions in 1849, 1869, and 1885. Source: Servicio Geológico Colombiano (SGC) https://www2.sgc.gov.co/volcanes/index.html <https://urldefense.com/v3/__https://www2.sgc.gov.co/volcanes/index.html__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH9jNxlUJQ$> Spurr | United States | 61.299°N, 152.251°W | Summit elev. 3374 m In a special information statement on 6 February, the Alaska Volcano Observatory (AVO) reported that unrest at Spurr continued and was likely caused by new magma beneath the volcano. The nature of the unrest and the 10-month duration suggested that an eruption remained a possibility. The most likely vent location would be at Crater Peak, which erupted in 1953 and 1992; less likely would be the summit vent, which erupted several thousand years ago. The rate of earthquakes increased from an average of 30 per week during April into early October to a rate of 125 per week from early October to 6 February. More than 2,700 earthquakes were located during the unrest episode thus far and the largest was a M 2.9 that occurred on 2 January 2, 2025. Earthquakes were clustered at two depth ranges, 0-10 km and 12-22 km, beneath both the summit and Crater Peak, though there was a recent increase in the number of earthquakes under Crater Peak. Increased seismicity was accompanied by around 6 cm of inflation detected by the Global Navigation Satellite System (GNSS) stations on the flanks and satellite data. Modeling indicated that the inflation source was located 3-5 km below sea level and 3-4 km W of the summit. A small lake appeared in the summer crater in the early part of the summer in 2024. The lake had grown to an area of about 5 acres. Active steaming from summit area fumaroles has not changed over the current period of unrest and is similar to observations from recent years. There were no significant surface changes at Crater Peak. Instruments aboard gas measurement flights on 23 June and 18 December 2024, and 7 February 2025, detected low levels of sulfur dioxide and carbon dioxide, similar to background levels measured in previous years. 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!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH9Ovn4iTg$> Ongoing Activity Ahyi | United States | 20.42°N, 145.03°E | Summit elev. -75 m Unrest at Ahyi Seamount continued during 31 January-7 February. A satellite image on 1 February showed a plume of discolored water in the vicinity of the seamount, indicating possible submarine activity. Signals indicting minor activity coming from the direction of Ahyi were identified in data from underwater pressure sensors near Wake Island (about 2,270 km E of Ahyi) on 3 and 5 February. 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!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH8UI5CLeQ$> 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 3-10 February. Nightly crater incandescence was visible in webcam images. An explosion at 1719 on 4 February was recorded by the seismic network, though details of any emissions were unknown. Explosions at 0702 on 6 February, at 0702, 1412, and 1946 on 8 February, and at 0556, 0737, and 2003 on 9 February generated ash plumes that rose 0.4-2 km above the crater rim and drifted SE. A few of the emissions rose into the weather clouds. Each of the explosions, except the one at 1412 on 8 February, ejected large blocks 400-1,200 m from the crater rim. 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!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH9Nm--GMg$> 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 4-11 February. Daily white-and-gray ash plumes rose 100-600 m above the crater rim and drifted E and SE. 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!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH-IAyWlgg$> El Misti | Peru | 16.294°S, 71.409°W | Summit elev. 5822 m The Instituto GeofÃsico del Perú (IGP) reported that a lahar carrying blocks descended the Matagente drainage on the NW flank of El Misti at 1637 on 7 February. The public was warned to stay away from drainages and roads on that flank. The Alert Level remained at Green (the lowest level on a four-color scale). Geologic Summary. El Misti is a symmetrical andesitic stratovolcano with nested summit craters that towers above the city of Arequipa, Peru. The modern symmetrical cone, constructed within a small 1.5 x 2 km wide summit caldera that formed between about 13,700 and 11,300 years ago, caps older Pleistocene volcanoes that underwent caldera collapse about 50,000 years ago. A large scoria cone has grown with the 830-m-wide outer summit crater. At least 20 tephra-fall deposits and numerous pyroclastic-flow deposits have been documented during the past 50,000 years, including a pyroclastic flow that traveled 12 km to the south about 2000 years ago. The most recent activity has been dominantly pyroclastic, and strong winds have formed a parabolic dune field of volcanic ash extending up to 20 km downwind. An eruption in the 15th century affected nearby Inca inhabitants. Some reports of historical eruptions may represent increased fumarolic activity. Source: Instituto GeofÃsico del Perú (IGP) http://www.igp.gob.pe/ <https://urldefense.com/v3/__http://www.igp.gob.pe/__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH-4R2O9oQ$> Fuego | Guatemala | 14.473°N, 90.88°W | Summit elev. 3763 m The Instituto Nacional de SismologÃa, VulcanologÃa, MeteorologÃa e HidrologÃa (INSIVUMEH) reported that low-level activity continued at Fuego during 4-11 February. Almost daily gas-and-steam emissions rose as high as 300 m above the summit and drifted downwind. Crater incandescence was observed during dark hours. Explosions have not been detected since 19 January. Geologic Summary. Volcán Fuego, one of Central America's most active volcanoes, is also one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between Fuego and Acatenango to the north. Construction of Meseta dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta may have produced the massive Escuintla debris-avalanche deposit, which extends about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at the mostly andesitic Acatenango. Eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. Frequent vigorous historical eruptions have been recorded since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH) http://www.insivumeh.gob.gt/ <https://urldefense.com/v3/__http://www.insivumeh.gob.gt/__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH-7F7J47g$> Gamalama | Indonesia | 0.81°N, 127.3322°E | Summit elev. 1714 m Although there was no eruptive activity reported at Gamalama, in a 5 February press release the Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) noted that the number of daily deep volcanic earthquakes had increased. A total of 36 deep volcanic earthquakes were recorded during 29 January-4 February, with the highest daily number (10) recorded on 1 February. The number of deep volcanic earthquakes generally averages 1-2 events per day. Other seismic signals were recorded during that period including three tornillo earthquakes and three earthquakes likely indicating emissions. Dense white plumes rose 200-100 m above the summit, remaining at typical levels. The Alert Level remained at 2 (on a scale of 1-4); visitors and residents were warned not to approach the crater within a 1.5-km radius. Geologic Summary. Gamalama is a near-conical stratovolcano that comprises the entire island of Ternate off the western coast of Halmahera, and is one of Indonesia's most active volcanoes. The island was a major regional center in the Portuguese and Dutch spice trade for several centuries, which contributed to the extensive documentation of activity. Three cones, progressively younger to the north, form the summit. Several maars and vents define a rift zone, parallel to the Halmahera island arc, that cuts the volcano; the S-flank Ngade maar formed after about 14,500â??13,000 cal. BP (Faral et al., 2022). Eruptions, recorded frequently since the 16th century, typically originated from the summit craters, although flank eruptions have occurred in 1763, 1770, 1775, and 1962-63. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH-IAyWlgg$> 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 lava flow in Great Sitkinâ??s summit crater during 4-11 February. Cloudy weather prevented clear satellite and webcam images. Small earthquakes were detected during 10-11 February. 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!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH9Ovn4iTg$> Ibu | Indonesia | 1.488°N, 127.63°E | Summit elev. 1325 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that the eruption at Ibu continued during 5-11 February. Multiple daily gray or white-and-gray ash plumes that were often dense rose as high as 1.2 km above the summit and drifted mainly SE and S. Incandescence at the summit was visible in some webcam images posted with the reports. The Alert Level remained at 3 (the second highest level on a four-level scale) and the public was advised to stay 4 km away from the active crater and 5 km away from the N crater wall opening. Geologic Summary. The truncated summit of Gunung Ibu stratovolcano along the NW coast of Halmahera Island has large nested summit craters. The inner crater, 1 km wide and 400 m deep, has contained several small crater lakes. The 1.2-km-wide outer crater is breached on the N, creating a steep-walled valley. A large cone grew ENE of the summit, and a smaller one to the WSW has fed a lava flow down the W flank. A group of maars is located below the N and W flanks. The first observed and recorded eruption was a small explosion from the summit crater in 1911. Eruptive activity began again in December 1998, producing a lava dome that eventually covered much of the floor of the inner summit crater along with ongoing explosive ash emissions. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH-IAyWlgg$> 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 4-11 February. The seismic network recorded 7-23 daily volcanic earthquakes, though during 5-6 February there was a total of 35 events. Average daily sulfur dioxide emissions ranged from 1,611 to 4,186 tonnes per day (t/d); emissions since 3 June 2024 averaged 4,484 t/d. Gas-and-steam emissions rose as high as 100 m above the summit and drifted W, WSW, and SW; plumes occasionally contained ash on 8 February. A minor explosive eruption began at 1511 on 6 February and lasted for two minutes based on seismic and infrasound data. An ash plume rose 600 m above the summit and drifted SW, causing minor ashfall in Mercedes and San Luis in the Sag-ang barangay (neighborhood) to the SW. The plume was partly obscured by rainy weather. The explosion was detected by instruments 5 km E and produced a booming sound reported in the barangays of Yubo (WSW) and Sag-ang. A sulfur odor was noted in several barangays in La Castellana to the S. Lahars descended the Buhangin River which flows through La Castellana and Moises Padilla. The National Disaster Risk Reduction and Management Council (NDRRMC) report issued at 0800 on 8 February stated that 9,835 people (3,106 families) were spread across 23 evacuation centers and another 8,383 people (2,651 families) were staying elsewhere. 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!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH-VWvj_qA$> ; The National Disaster Risk Reduction and Management Council (NDRRMC) http://www.ndrrmc.gov.ph/ <https://urldefense.com/v3/__http://www.ndrrmc.gov.ph/__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH-2pErEhw$> 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 30 January-6 February. A weak thermal anomaly over the volcano was identified in satellite images during 30 January and 1-3 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!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH9hsQPbBw$> Lewotobi | Indonesia | 8.542°S, 122.775°E | Summit elev. 1703 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity continued at Lewotobi Laki-laki during 4-11 February. At 0108 on 5 February a dense gray ash plume rose 400 m above the summit and drifted N and NE. White emissions rose as high as 300 m above the summit and drifted N, NE, and E on the other days of the week. Eruptive events were recorded during 6-7 February, but emissions were not observed. The Alert Level remained at 3 (on a scale of 1-4). The exclusion zone was lowered on 8 February; the public was warned to stay 4 km away from the center of Laki-laki and 5 km in a semicircle counterclockwise from the NE to the SW. Geologic Summary. The Lewotobi edifice in eastern Flores Island is composed of the two adjacent Lewotobi Laki-laki and Lewotobi Perempuan stratovolcanoes (the "husband and wife"). Their summits are less than 2 km apart along a NW-SE line. The conical Laki-laki to the NW has been frequently active during the 19th and 20th centuries, while the taller and broader Perempuan has had observed eruptions in 1921 and 1935. Small lava domes have grown during the 20th century in both of the summit craters, which are open to the north. A prominent cone, Iliwokar, occurs on the E flank of Perampuan. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH-IAyWlgg$> Marapi | Indonesia | 0.38°S, 100.474°E | Summit elev. 2885 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that white plumes rose 100-200 m above the summit of Marapi (on Sumatra) during 5-10 February and drifted in multiple directions. An eruptive event was recorded at 1820 on 7 February but emission heights were unknown. The Darwin VAAC reported that an ash plume was visible in a satellite image at 0620 on 8 February drifting E at an estimated altitude of 3 km (10,000 ft) a.s.l. 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. 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!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH-IAyWlgg$> ; Darwin Volcanic Ash Advisory Centre (VAAC) http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml <https://urldefense.com/v3/__http://www.bom.gov.au/aviation/volcanic-ash/darwin-va-advisory.shtml__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH-b-sj5PA$> 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 31 January-6 February. Seismicity remained at high levels. The SW lava dome produced 88 lava avalanches that traveled as far as 2 km SW down the Bebeng drainage, 31 that traveled as far as 2 km SW down the Krasak drainage, and 13 that traveled as far as 1.8 km SW down the Sat/Putih drainage. Morphological changes at the SW dome were caused by continuing effusion and collapses of material; the dome had an estimated volume of 3,315,900 cubic meters based on an analysis of 4 February aerial photos. No significant morphological changes at the summit dome were visible. 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!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH8sWv8e0w$> Nevado del Ruiz | Colombia | 4.892°N, 75.324°W | Summit elev. 5279 m Servicio Geológico Colombianoâ??s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that eruptive activity at Nevado del Ruiz continued during 4-10 February. Seismic data indicated that events associated with fluid movement increased in both number and intensity compared to the previous week. Webcam images, observations from residents, and reports from the Parque Nacional Natural Los Nevados confirmed some ash emissions and higher-temperature ejecta were associated with some of these events. Notably, Long-duration seismic signals associated with continuous ash emissions were only recorded on 4 February. Gas-and-ash plumes rose as high as 1.5 km above the summit and drifted NW, W, and SW; taller plumes, recorded during 9-10 February, rose as high as 2 km as they drifted downwind. Seismicity associated with rock fracturing was similar in number but higher in magnitude compared to the previous week. The earthquakes were located below Arenas Crater and the NE, E, and ESE flanks within 13 km, and had depths of 1-9 km. Two earthquakes were felt by residents on 6 February: a M 2 that occurred at 0131 and was located 6 km E of the crater at a depth of 3 km and a M 2.3 that occurred at 2024 and was located 5 km ESE of the crater at a depth of 4 km. Low-energy thermal anomalies on the crater floor were identified in satellite data. Sulfur dioxide emissions detected in satellite data continued to be significant. The Alert Level remained at Yellow (the second level on a four-level scale), and the public was warned to stay out of the restricted areas around Arenas Crater, not to spend long periods of time on the Murillo-Cerro Gualà Road, and to avoid drainages in the high-threat zones. Geologic Summary. Nevado del Ruiz is a broad, glacier-covered volcano in central Colombia that covers more than 200 km2. Three major edifices, composed of andesitic and dacitic lavas and andesitic pyroclastics, have been constructed since the beginning of the Pleistocene. The modern cone consists of a broad cluster of lava domes built within the caldera of an older edifice. The 1-km-wide, 240-m-deep Arenas crater occupies the summit. The prominent La Olleta pyroclastic cone located on the SW flank may also have been active in historical time. Steep headwalls of massive landslides cut the flanks. Melting of its summit icecap during historical eruptions, which date back to the 16th century, has resulted in devastating lahars, including one in 1985 that was South America's deadliest eruption. Source: Servicio Geológico Colombiano (SGC) https://www2.sgc.gov.co/volcanes/index.html <https://urldefense.com/v3/__https://www2.sgc.gov.co/volcanes/index.html__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH9jNxlUJQ$> Nyamulagira | DR Congo | 1.408°S, 29.2°E | Summit elev. 3058 m Satellite images acquired on 21 and 31 January showed continuing activity at Nyamuragira. A thermal anomaly in the summit crater was visible, though weather and/or volcanic emissions obscured most of the crater. A lava flow on the W flank was visible in the 31 January image and was about 890 m long. Dense weather clouds obscured the volcano in a 5 February satellite image. Geologic Summary. Africa's most active volcano, Nyamulagira (also known as Nyamuragira), is a massive high-potassium basaltic shield about 25 km N of Lake Kivu and 13 km NNW of the steep-sided Nyiragongo volcano. The summit is truncated by a small 2 x 2.3 km caldera that has walls up to about 100 m high. Documented eruptions have occurred within the summit caldera, as well as from the numerous flank fissures and cinder cones. A lava lake in the summit crater, active since at least 1921, drained in 1938, at the time of a major flank eruption. Recent lava flows extend down the flanks more than 30 km from the summit as far as Lake Kivu; extensive lava flows from this volcano have covered 1,500 km2 of the western branch of the East African Rift. Source: Copernicus https://www.copernicus.eu/en <https://urldefense.com/v3/__https://www.copernicus.eu/en__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH8KAiuseQ$> Reventador | Ecuador | 0.077°S, 77.656°W | Summit elev. 3562 m The Instituto GeofÃsico-Escuela Politécnica Nacional (IG-EPN) reported that eruptive activity continued at Reventador during 4-11 February. Seismicity included 57-101 daily explosions, long-period earthquakes, harmonic tremor, and tremor associated with emissions. Weather conditions occasionally obscured views of summit activity; however, when the weather permitted, ash-and-gas plumes were observed in webcam and/or satellite images rising 200-1,100 m above the crater and drifting N, NW, W, and SW. The surveillance camera network recorded multiple instances of incandescent material descending the flanks as far as 900 m below the crater rim. On 4 February a pyroclastic flow traveled 500 m down the S flank. SecretarÃa de Gestión de Riesgos maintained the Alert Level at Orange (the second highest level on a four-color scale). Geologic Summary. Volcán El Reventador is the most frequently active of a chain of Ecuadorian volcanoes in the Cordillera Real, well east of the principal volcanic axis. The forested, dominantly andesitic stratovolcano has 4-km-wide avalanche scarp open to the E formed by edifice collapse. A young, unvegetated, cone rises from the amphitheater floor to a height comparable to the rim. It has been the source of numerous lava flows as well as explosive eruptions visible from Quito, about 90 km ESE. Frequent lahars in this region of heavy rainfall have left extensive deposits on the scarp slope. The largest recorded eruption took place in 2002, producing a 17-km-high eruption column, pyroclastic flows that traveled up to 8 km, and lava flows from summit and flank vents. Sources: Instituto GeofÃsico-Escuela Politécnica Nacional (IG-EPN) http://www.igepn.edu.ec/ <https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH8Ucb53Tw$> ; SecretarÃa de Gestión de Riesgos (SGR) http://www.gestionderiesgos.gob.ec/ <https://urldefense.com/v3/__http://www.gestionderiesgos.gob.ec/__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH_ryGInfA$> Sangay | Ecuador | 2.005°S, 78.341°W | Summit elev. 5286 m The Instituto GeofÃsico-Escuela Politécnica Nacional (IG-EPN) reported that moderate levels of eruptive activity continued at Sangay during 4-11 February. The seismic network recorded 20-145 daily explosions. On a few days gas-and-ash plumes were visible rising as high as 1 km above the summit and drifting S, SW, and NW, though weather clouds obscured views of the volcano most of the time. Incandescence at the crater was occasionally visible. SecretarÃa de Gestión de Riesgos (SGR) maintained the Alert Level at Yellow (the second highest level on a four-color scale). Geologic Summary. The isolated Sangay volcano, located east of the Andean crest, is the southernmost of Ecuador's volcanoes and its most active. The steep-sided, glacier-covered, dominantly andesitic volcano grew within the open calderas of two previous edifices which were destroyed by collapse to the east, producing large debris avalanches that reached the Amazonian lowlands. The modern edifice dates back to at least 14,000 years ago. It towers above the tropical jungle on the east side; on the other sides flat plains of ash have been eroded by heavy rains into steep-walled canyons up to 600 m deep. The earliest report of an eruption was in 1628. Almost continuous eruptions were reported from 1728 until 1916, and again from 1934 to the present. The almost constant activity has caused frequent changes to the morphology of the summit crater complex. Sources: Instituto GeofÃsico-Escuela Politécnica Nacional (IG-EPN) http://www.igepn.edu.ec/ <https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH8Ucb53Tw$> ; SecretarÃa de Gestión de Riesgos (SGR) http://www.gestionderiesgos.gob.ec/ <https://urldefense.com/v3/__http://www.gestionderiesgos.gob.ec/__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH_ryGInfA$> Santa Maria | Guatemala | 14.757°N, 91.552°W | Summit elev. 3745 m The Instituto Nacional de SismologÃa, VulcanologÃa, MeteorologÃa e HidrologÃa (INSIVUMEH) reported ongoing eruptive activity at Santa Mariaâ??s Santiaguito dome complex during 4-11 February with continuing lava extrusion at Caliente dome. Daily explosions, as many as seven per hour when reported, generated gas-and-ash plumes that rose as high as 1.2 km above the dome and drifted SW and W. Effusion of blocky lava and collapses of material produced daily block avalanches that were sometimes heard several kilometers away; these mainly descended the SW and S flanks, but occasionally went SE and E. Incandescence was visible at the crater and upper part of the WSW flank lava flow, and occasionally from ejected incandescent blocks. During 9-10 February ashfall was reported at Finca Monte Bello (6 km WSW) and surrounding areas. Explosions and collapses generated short pyroclastic flows during 10-11 February. Geologic Summary. Symmetrical, forest-covered Santa MarÃa volcano is part of a chain of large stratovolcanoes that rise above the Pacific coastal plain of Guatemala. The sharp-topped, conical profile is cut on the SW flank by a 1.5-km-wide crater. The oval-shaped crater extends from just below the summit to the lower flank, and was formed during a catastrophic eruption in 1902. The renowned Plinian eruption of 1902 that devastated much of SW Guatemala followed a long repose period after construction of the large basaltic-andesite stratovolcano. The massive dacitic Santiaguito lava-dome complex has been growing at the base of the 1902 crater since 1922. Compound dome growth at Santiaguito has occurred episodically from four vents, with activity progressing E towards the most recent, Caliente. Dome growth has been accompanied by almost continuous minor explosions, with periodic lava extrusion, larger explosions, pyroclastic flows, and lahars. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH) http://www.insivumeh.gob.gt/ <https://urldefense.com/v3/__http://www.insivumeh.gob.gt/__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH-7F7J47g$> 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 5-11 February with daily eruptive events recorded by the seismic network. White-and-gray ash plumes rose 300-900 m above the summit and drifted NE, N, and SW. Emissions were not visible on 5 and 10 February. 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!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH-IAyWlgg$> Sheveluch | Russia | 56.653°N, 161.36°E | Summit elev. 3283 m The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that lava extrusion may have continued at Sheveluchâ??s â??300 years of RASâ?? dome on the SW flank of Old Sheveluch and at the Young Sheveluch dome during 30 January-6 February. Daily thermal anomalies over the domes were identified in satellite images. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted. Geologic Summary. The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1,300 km3 andesitic volcano is one of Kamchatka's largest and most active volcanic structures, with at least 60 large eruptions during the Holocene. The summit of roughly 65,000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera breached to the south. Many lava domes occur on its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large open caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka. Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH9hsQPbBw$> 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 3-10 February. Incandescence was observed nightly in webcam images. An explosion at 0738 on 8 February generated an ash plume that rose 600 m above the crater rim, drifted SE, and entered weather clouds. Large blocks were ejected 400 m from the vent. 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!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH9Nm--GMg$> Ubinas | Peru | 16.345°S, 70.8972°W | Summit elev. 5608 m The Instituto GeofÃsico del Perú (IGP) reported that a lahar carrying blocks descended the Sacohaya River on the S flank of Ubinas at 1618 on 10 February. The public was warned to stay away from the drainage and to take precautions while driving on the Arequipa-Querapi-Ubinas-Huarina highway. The Alert Level remained at Yellow (the second level on a four-color scale) and the public was warned to stay 2 km away from the crater. Geologic Summary. The truncated appearance of Ubinas, Perú's most active volcano, is a result of a 1.4-km-wide crater at the summit. It is the northernmost of three young volcanoes located along a regional structural lineament about 50 km behind the main volcanic front. The growth and destruction of Ubinas I was followed by construction of Ubinas II beginning in the mid-Pleistocene. The upper slopes of the andesitic-to-rhyolitic Ubinas II stratovolcano are composed primarily of andesitic and trachyandesitic lava flows and steepen to nearly 45°. The steep-walled, 150-m-deep summit crater contains an ash cone with a 500-m-wide funnel-shaped vent that is 200 m deep. Debris-avalanche deposits from the collapse of the SE flank about 3,700 years ago extend 10 km from the volcano. Widespread Plinian pumice-fall deposits include one from about 1,000 years ago. Holocene lava flows are visible on the flanks, but activity documented since the 16th century has consisted of intermittent minor-to-moderate explosive eruptions. Source: Instituto GeofÃsico del Perú (IGP) http://www.igp.gob.pe/ <https://urldefense.com/v3/__http://www.igp.gob.pe/__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH-4R2O9oQ$> Whakaari/White Island | New Zealand | 37.52°S, 177.18°E | Summit elev. 294 m On 10 February GeoNet reported that weak-to-moderate gas-and-steam plumes from Whakaari/White Island during the previous week did not contain ash. Gas-and-steam plumes were visible in images from satellite and webcams (at Whakatane and Te Kaha), and during clearer weather conditions a larger plume was occasionally visible from the Bay of Plenty. Recent activity was consistent with moderate-to-heightened levels of unrest, therefore the Volcanic Alert Level remained at 2 (on a scale of 0-5). The Aviation Color Code was lowered to Yellow (the second lowest level on a four-color scale) due to the absence of ash in the emissions. GeoNet relies on remote cameras and satellite images to monitor Whakaari and noted that there is uncertainty due to the current lack of consistent, usable, real-time monitoring data. Geologic Summary. The uninhabited Whakaari/White Island is the 2 x 2.4 km emergent summit of a 16 x 18 km submarine volcano in the Bay of Plenty about 50 km offshore of North Island. The island consists of two overlapping andesitic-to-dacitic stratovolcanoes. The SE side of the crater is open at sea level, with the recent activity centered about 1 km from the shore close to the rear crater wall. Volckner Rocks, sea stacks that are remnants of a lava dome, lie 5 km NW. Descriptions of volcanism since 1826 have included intermittent moderate phreatic, phreatomagmatic, and Strombolian eruptions; activity there also forms a prominent part of Maori legends. The formation of many new vents during the 19th and 20th centuries caused rapid changes in crater floor topography. Collapse of the crater wall in 1914 produced a debris avalanche that buried buildings and workers at a sulfur-mining project. Explosive activity in December 2019 took place while tourists were present, resulting in many fatalities. The official government name Whakaari/White Island is a combination of the full Maori name of Te Puia o Whakaari ("The Dramatic Volcano") and White Island (referencing the constant steam plume) given by Captain James Cook in 1769. Source: GeoNet http://www.geonet.org.nz/ <https://urldefense.com/v3/__http://www.geonet.org.nz/__;!!IKRxdwAv5BmarQ!dQvyCS98TEX0MEZrfwBcFv0p_7qspveU6m_kFz3INasa_ddWws0Ra6RB3PrbhBGCxcXSmRG4FgOiEkScPH-FOE8LZQ$> 1-1-1-1-1-1-1-1-1-1-1-1-1-1 ============================================================== 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 - http://pdx.edu/ GVP - https://volcano.si.edu/ IAVCEI - https://www.iavceivolcano.org/ To subscribe to the volcano list, send the message: subscribe volcano to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxx To unsubscribe from the volcano list, send the message: signoff volcano to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxx. 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