5-5-5-5-5-5-5-5-5-5-5-5-5-5 From: Sally Kuhn Sennert <kuhns@xxxxxx> Smithsonian / USGS Weekly Volcanic Activity Report 30 November-6 December 2022 Sally Kuhn Sennert - Weekly Report Editor (kuhns@xxxxxx) URL: https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AQIHIJGC$ <https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPYPj9cqE$> New Activity/Unrest: Ahyi, Mariana Islands (USA) | Cotopaxi, Ecuador | Etna, Sicily (Italy) | Mauna Loa, Hawaiian Islands (USA) | San Miguel, Eastern El Salvador | Semeru, Eastern Java | Taupo, North Island (New Zealand) | Villarrica, Central Chile Ongoing Activity: Aira, Kyushu (Japan) | Alaid, Kuril Islands (Russia) | Dukono, Halmahera | Ebeko, Paramushir Island (Russia) | Fuego, South-Central Guatemala | Great Sitkin, Andreanof Islands (USA) | Kerinci, Central Sumatra | Kilauea, Hawaiian Islands (USA) | Late, Tonga Ridge | Machin, Colombia | Merapi, Central Java | Nevado del Ruiz, Colombia | Pavlof, Alaska Peninsula, Alaska | Popocatepetl, Mexico | Reventador, Ecuador | Santa Maria, Southwestern Guatemala | Sheveluch, Central Kamchatka (Russia) | Stromboli, Aeolian Islands (Italy) | Suwanosejima, Ryukyu Islands (Japan) 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 Ahyi | Mariana Islands (USA) | 20.42°N, 145.03°E | Summit elev. -75 m Unrest continued to be detected at Ahyi Seamount during 30 November-6 December. Wake Island hydrophone sensors detected signals on most days and discolored water over the seamount was identified daily in satellite images. 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 sea surface about 18 km SE of the island of Farallon de Pajaros (Uracas) 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 of the seamount, 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://urldefense.com/v3/__https://www.usgs.gov/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AT4UHAJf$ <https://urldefense.com/v3/__https://www.usgs.gov/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPhHlsKvk$> Cotopaxi | Ecuador | 0.677°S, 78.436°W | Summit elev. 5911 m IG reported that the low-level eruption at Cotopaxi continued during 30 November-6 December. At 0841 on 30 November the seismic network recorded a signal associated with an emission. A gas plume with low ash content was visible in webcam images rising 600 m above the summit and drifting E. Earlier in the morning minor ashfall was reported in Latacunga, though the ashfall may have been the result of remobilized material previously deposited. Daily steam-and-gas emissions during 1-6 December rose as high as 1.5 km above the summit and drifted E, SE, S, and W. Daily sulfur dioxide emissions measured by satellite during 1-4 December averaged 119-4,000 tons per day. On 2 December IG noted that the heights of gas-and-steam emissions had increased in the past few weeks, corresponding to greater gas output. Thermal anomalies in the crater were visible in recent days; one was visible on 1 November, and two were visible on each of the days of 28 and 29 November. Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE) maintained the Alert Level at Yellow (the second lowest level on a four-color scale). Geologic Summary. The symmetrical, glacier-covered, Cotopaxi stratovolcano is Ecuador's most well-known volcano and one of its most active. The steep-sided cone is capped by nested summit craters, the largest of which is about 550 x 800 m in diameter. Deep valleys scoured by lahars radiate from the summit of the andesitic volcano, and large andesitic lava flows extend to its base. The modern edifice has been constructed since a major collapse sometime prior to about 5,000 years ago. Pyroclastic flows (often confused in historical accounts with lava flows) have accompanied many explosive eruptions, and lahars have frequently devastated adjacent valleys. Strong eruptions took place in 1744, 1768, and 1877. Pyroclastic flows descended all sides of the volcano in 1877, and lahars traveled more than 100 km into the Pacific Ocean and western Amazon basin. Smaller eruptions have been frequent since that time. Sources: Instituto GeofÃsico-Escuela Politécnica Nacional (IG) https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AUrrZx36$ <https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPxkbZdfA$> ; Servicio Nacional de Gestión de Riesgos y Emergencias (SNGRE) https://urldefense.com/v3/__https://www.gestionderiesgos.gob.ec/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AboyBEBG$ <https://urldefense.com/v3/__https://www.gestionderiesgos.gob.ec/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPERIo6GY$> Etna | Sicily (Italy) | 37.748°N, 14.999°E | Summit elev. 3357 m INGV reported that a new vent, at the NE base of Etnaâ??s SE Crater around 2,800 m elevation, was first seen at about 1800 on 27 November when weather conditions allowed for direct visual observations. The vent produced a lava flow that traveled 300 m E towards the Valle del Leone. Inclement weather conditions from 1000 on 28 November until the end of the next day prevented confirmation of continuing activity, though incandescent flashes in the clouds suggested ongoing effusion. The weather conditions improved on 30 November, and a second vent was observed, located upslope from the first at about 2,900 m elevation. A lava flow from the second vent had traveled about 450 parallel to and N of the first flow, reaching about 2,700 m elevation. 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) https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1ASMwYZhU$ <https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVP2VckjuA$> Mauna Loa | Hawaiian Islands (USA) | 19.475°N, 155.608°W | Summit elev. 4170 m HVO reported that the Northeast Rift Zone eruption at Mauna Loa continued during 30 November-6 December. Fissure 4, at the lowest elevation, produced lava flows that moved NE at a rate of about 60 m per hour during 30 November-1 December and crossed the Mauna Loa Weather Observatory Road overnight. A smaller slower lobe of lava traveled E but had stalled by the afternoon of 1 December. Fissure 4 was not very active during the morning of 2 December, and during an overflight on 3 December HVO geologists confirmed that it was no longer erupting and observed only glowing cracks in the vicinity. Fissure 3, at 3,510 m elevation, was the dominant source of the largest lava flow that continued to advance mainly N towards the Daniel K. Inouye Highway (Saddle Road) during the week. The main flow branched almost halfway down the flow field, but coalesced downslope an advanced as a single front. Lava fountains at the fissure were 20-25 m tall on 30 November, about 33 m tall during 3-4 December, and 40-100 m on 6 December. Molten lava bombs were sometimes ejected, which cooled at the base of the fissure and built a significant spatter rampart around the lava fountains. The rate of lava flow advancement was variable but generally trended down early in the week from 24-45 m per hour during 30 November-2 December to 6-13 m per hour during 3-5 December, as the lava-flow front reached flatter ground. As the flow rate slowed the flow front was widened and thickened. There were surges in the rate during 5-6 December with the lava flow typically advancing at 21 m per hour but moving up to 27.4 m per hour for shorter periods. Several small overflows were visible during 3-6 December near where the main lava flow branched, on the steeper slopes of the NE flank about halfway down the lava flow. By 0500 on 6 December the flow front was about 3.5 km from the highway; weather conditions hampered views of the eruption most of the day. The eruption produced volcanic gas plumes that rose to high altitudes and drifted W, generating vog in areas downwind. Pele's hair (strands of volcanic glass) fell in the Humuâ??ula Saddle area, and were also blown great distances, as far as far Laupahoehoe (59 km NW of Fissure 3), and the Mauna Kea Visitor Information Station. Hawaiâ??i Volcanoes National Park had closed the Mauna Loa Road from Kipukapuaulu, and the closure extended to the summit caldera. Sulfur dioxide emission rates were high through the week with approximate rates of 180,000 tonnes per day on 1 December and 120,000 tonnes per day on 4 December. At 0180 on 4 December the Aviation Color Code was lowered to Orange (the second highest level on a four-color scale) because there was no current threat to aviation from significant volcanic ash emissions. The Federal Aviation Administration issued a temporary flight restriction extending from the surface to 1,500 ft (457 m) above ground level in the eruption area. The Volcano Alert Level remained at Warning (the highest level on a four-level scale) reflecting the ongoing lava-flow hazards. Geologic Summary. Massive Mauna Loa is a basaltic shield volcano that rises almost 9 km from the ocean floor to form the world's largest Holocene volcano. Flank eruptions typically occur from the lengthy NE and SW rift zones, and from the Moku'aweoweo summit is caldera, which is within an older and larger 6 x 8 km caldera. Two of the youngest large debris avalanches documented in Hawaii traveled nearly 100 km from Mauna Loa; the second of the Alika avalanches was emplaced about 105,000 years ago (Moore et al., 1989). Almost 90% of the surface of the volcano is covered by lavas less than 4,000 years old (Lockwood and Lipman, 1987). Beginning about 1,500 years ago, a series of voluminous overflows from a summit lava lake covered about 25% of the volcano's surface. Over the last 750 years, from shortly after the formation of Moku'aweoweo caldera until the present, an additional 25% of the volcano has been covered with lava flows, mainly from summit and NW rift zone vents. Source: US Geological Survey Hawaiian Volcano Observatory (HVO) https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1ARudOhs9$ <https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPD9sOc1s$> San Miguel | Eastern El Salvador | 13.434°N, 88.269°W | Summit elev. 2130 m MARN reported that a total of 194 explosions were recorded at San Miguel during 15-29 November, with a daily average of 12 events. Gas, steam, and ash plumes generally rose 500 m above the crater rim, though plumes occasionally rose higher, particularly during 26-27 November as activity intensified. No explosions were detected during 30 November-6 December and seismicity decreased. MARN noted that those living within a 5 km radius should identify evacuation routes and to take preparation measures identified by the Sistema Nacional de Protección Civil. Geologic Summary. The symmetrical cone of San Miguel, one of the most active volcanoes in El Salvador, rises from near sea level to form one of the country's most prominent landmarks. A broad, deep, crater complex that has been frequently modified by eruptions recorded since the early 16th century caps the truncated unvegetated summit, also known locally as Chaparrastique. Flanks eruptions of the basaltic-andesitic volcano have produced many lava flows, including several during the 17th-19th centuries that extended to the N, NE, and SE. The SE-flank flows are the largest and form broad, sparsely vegetated lava fields crossed by highways and a railroad skirting the base of the volcano. Flank vent locations have migrated higher on the edifice during historical time, and the most recent activity has consisted of minor ash eruptions from the summit crater. Sources: Ministerio de Medio Ambiente y Recursos Naturales (MARN) https://urldefense.com/v3/__https://marn.gob.sv/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AecSGQ2c$ <https://urldefense.com/v3/__https://marn.gob.sv/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPtxp8iX0$> ; Protección Civil de El Salvador https://urldefense.com/v3/__https://www.proteccioncivil.gob.sv/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AeK1dyzi$ <https://urldefense.com/v3/__https://www.proteccioncivil.gob.sv/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPsJHJb0M$> Semeru | Eastern Java | 8.108°S, 112.922°E | Summit elev. 3657 m PVMBG reported that the eruption at Semeru was ongoing the past month, culminating in a collapse of lava causing notable pyroclastic flows and ash plumes on 4 December. During 1 November-2 December an average of 88 daily white-and-gray ash plumes of variable densities were visually observed rising as high as 1.5 km above the summit. Pyroclastic flows, seen twice, traveled as far as 4.5 km down the flank. Deformation data showed inflation and thermal anomalies indicated hot lava-dome material at the summit. A white-to-gray ash plume rose around 500 m above the summit and drifted S on 3 December. At 0246 on 4 December material collapsed on the SE flank, producing a series of pyroclastic flows that mainly traveled 5-13 km SE and S, and as far as 19 km in those same directions, according to BNPB. The pyroclastic flows overtook the Gladak Perak Bridge, 13 km SE of the summit, which connected residents of Pronojiwo (13 km SE) and Lumajang (32 km ESE) and appeared to be under construction based on pictures posted on social media. Dense dark-gray ash plumes rose along the pyroclastic flows up to 1.5 km above the summit and drifted SE and S. The ash plumes caused dark conditions and limited visibility, especially in Kajar Kuning (12 km SE) where residents reported dense ashfall and heavy rain. Ejected incandescent material was deposited as far as 8 km from the summit, and ashfall was reported in areas 12 km SE. Pyroclastic flows were ongoing at least through 0951, traveling 5-7 km down the flanks. At 1200 PVMBG raised the Alert Level to 4 (the highest level on a scale of 1-4) and warned the public to stay at least 8 km away from the summit, and 500 m from Kobokan drainages within 17 km of the summit, along with other drainages originating on Semeru, including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards. A total of 1,979 people were evacuated to 11 centers, a public kitchen was established, and thousands of masks were distributed to minimize respiratory health risks due to volcanic ash. 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. Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AZh-eISy$ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPUnwZMHg$> ; Badan Nacional Penanggulangan Bencana (BNPB) https://urldefense.com/v3/__http://www.bnpb.go.id/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1ARkDGQmn$ <https://urldefense.com/v3/__http://www.bnpb.go.id/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVP4JJOmyA$> Taupo | North Island (New Zealand) | 38.82°S, 176°E | Summit elev. 760 m GeoNet reported that a strong M 5.6 earthquake occurred beneath Taupo on 30 November. The event was widely felt and caused a small tsunami in the lake. Lake water inundated the shore at several locations, mostly along the N shore, traveling inland as far as 40 m at Wharewaka Point (along the NE shore). Both the earthquake and the tsunami caused minor local damage. The instrument at Horomatangi recorded 250 mm of horizontal ground movement towards the SE, the largest movement ever recorded at that location. Other onshore stations recorded smaller movements of around 10-20 mm. More than 600 aftershocks were located by 7 December, though the magnitude and rate of the events had begun to decline. The largest aftershock was an M 4.5 and two other M 4 events were also recorded. Earthquakes larger than M 5 beneath Lake Taupo had occurred only four times since 1952, including a M 5 event that occurred on 4 September 2019 as part of a previous period of volcanic unrest. GeoNet noted that there had been 17 previous episodes of unrest at Taupo over the previous 150 years, some more notable than the current episode, and many others before written records. None resulted in an eruption, with the last eruption occurring around 232 CE. The Volcanic Alert Level remained at 1 (the second lowest level on a six-level scale) and the Aviation Color Code remained at Green (the lowest level on a four-color scale). Geologic Summary. Taupo, the most active rhyolitic volcano of the Taupo volcanic zone, is a large, roughly 35-km-wide caldera with poorly defined margins. It is a type example of an "inverse volcano" that slopes inward towards the most recent vent location. The caldera, now filled by Lake Taupo, largely formed as a result of the voluminous eruption of the Oruanui Tephra about 22,600 years before present (BP). This was the largest known eruption at Taupo, producing about 1,170 km3 of tephra. This eruption was preceded during the late Pleistocene by the eruption of a large number of rhyolitic lava domes north of Lake Taupo. Large explosive eruptions have occurred frequently during the Holocene from many vents within Lake Taupo and near its margins. The most recent major eruption took place about 1800 years BP from at least three vents along a NE-SW-trending fissure centered on the Horomotangi Reefs. This extremely violent eruption was New Zealand's largest during the Holocene and produced the thin but widespread phreatoplinian Taupo Ignimbrite, which covered 20,000 km2 of North Island. Source: GeoNet https://urldefense.com/v3/__http://www.geonet.org.nz/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1ASv-HLGW$ <https://urldefense.com/v3/__http://www.geonet.org.nz/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPVPNakeA$> Villarrica | Central Chile | 39.42°S, 71.93°W | Summit elev. 2847 m SERNAGEOMIN reported that on 1 December weather conditions were clear, allowing for good visual observations of the Villarrica summit. Ejected incandescent material was visible rising 80-220 m above the crater rim. The report noted that gas emissions and high-temperature thermal anomalies had been continuous during the previous few days. The Alert Level remained at Yellow (the second lowest level on a four-color scale) and the public was warned that material could be ejected within 500 m of the crater. ONEMI remained the Alert Level Yellow (the middle level on a three-color scale) for the municipalities of Villarrica, Pucón (16 km N), Curarrehue, and the commune of Panguipulli. Geologic Summary. Glacier-clad Villarrica, one of Chile's most active volcanoes, rises above the lake and town of the same name. It is the westernmost of three large stratovolcanoes that trend perpendicular to the Andean chain. A 6-km-wide caldera formed during the late Pleistocene. A 2-km-wide caldera that formed about 3500 years ago is located at the base of the presently active, dominantly basaltic to basaltic-andesitic cone at the NW margin of the Pleistocene caldera. More than 30 scoria cones and fissure vents dot the flanks. Plinian eruptions and pyroclastic flows that have extended up to 20 km from the volcano were produced during the Holocene. Lava flows up to 18 km long have issued from summit and flank vents. Historical eruptions, documented since 1558, have consisted largely of mild-to-moderate explosive activity with occasional lava effusion. Glaciers cover 40 km2 of the volcano, and lahars have damaged towns on its flanks. Sources: Servicio Nacional de GeologÃa y MinerÃa (SERNAGEOMIN) https://urldefense.com/v3/__http://www.sernageomin.cl/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AdO1admC$ <https://urldefense.com/v3/__http://www.sernageomin.cl/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPJEiIfJ0$> ; Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI) https://urldefense.com/v3/__http://www.onemi.cl/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AY6BUlKJ$ <https://urldefense.com/v3/__http://www.onemi.cl/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPl7vVJYk$> Ongoing Activity Aira | Kyushu (Japan) | 31.593°N, 130.657°E | Summit elev. 1117 m JMA reported ongoing eruptive activity at Minamidake Crater (at Aira Calderaâ??s Sakurajima volcano) consisting of a few eruptive events and two explosions. Crater incandescence was visible nightly, sometimes characterized as incandescent flashes. An explosion at 0340 on 2 December produced an ash plume that rose as high as 3.2 km above the crater rim and ejected large blocks as far as 1.1 km from the vent. The second explosion, recorded at 1929 on 3 December, produced an ash plume that rose as high as 3 km and ejected large blocks 1-1.3 km away. Webcam video of the event showed incandescent material ejected above the crater and lightning in the ash plume. The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from the crater. Geologic Summary. The Aira caldera in the northern half of Kagoshima Bay contains the post-caldera Sakurajima volcano, one of Japan's most active. Eruption of the voluminous Ito pyroclastic flow accompanied formation of the 17 x 23 km caldera about 22,000 years ago. The smaller Wakamiko caldera was formed during the early Holocene in the NE corner of the Aira caldera, along with several post-caldera cones. The construction of Sakurajima began about 13,000 years ago on the southern rim of Aira caldera and built an island that was finally joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kitadake summit cone ended about 4850 years ago, after which eruptions took place at Minamidake. Frequent historical eruptions, recorded since the 8th century, have deposited ash on Kagoshima, one of Kyushu's largest cities, located across Kagoshima Bay only 8 km from the summit. The largest historical eruption took place during 1471-76. Sources: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AW3qIbAG$ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPB4luDeE$> ; Treasure Official Channel https://urldefense.com/v3/__https://www.youtube.com/@zaihoofficialchannel__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1ATK1VDDo$ <https://urldefense.com/v3/__https://www.youtube.com/@zaihoofficialchannel__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPe_PqEKc$> Alaid | Kuril Islands (Russia) | 50.861°N, 155.565°E | Summit elev. 2285 m KVERT reported that the eruption at Alaid was ongoing during 25 November-1 December. A daily thermal anomaly was identified in satellite images. Ash plumes drifted 220 km SE during 25-26 November. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted. Geologic Summary. The highest and northernmost volcano of the Kuril Islands, Alaid is a symmetrical stratovolcano when viewed from the north, but has a 1.5-km-wide summit crater that is breached open to the south. This basaltic to basaltic-andesite volcano is the northernmost of a chain constructed west of the main Kuril archipelago. Numerous pyroclastic cones are present the lower flanks, particularly on the NW and SE sides, including an offshore cone formed during the 1933-34 eruption. Strong explosive eruptions have occurred from the summit crater beginning in the 18th century. Reports of eruptions in 1770, 1789, 1821, 1829, 1843, 1848, and 1858 were considered incorrect by Gorshkov (1970). Explosive eruptions in 1790 and 1981 were among the largest reported in the Kuril Islands. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1Aa1g2bBO$ <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVP8o7gRKQ$> Dukono | Halmahera | 1.693°N, 127.894°E | Summit elev. 1229 m PVMBG reported that almost daily white-and-gray plumes from Dukono rose as high as 450 m above the summit and drifted NE, E, S, and SW during 30 November-6 December. Inclement weather conditions sometimes prevented visual observations. The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 2-km exclusion zone. Geologic Summary. Reports from this remote volcano in northernmost Halmahera are rare, but Dukono has been one of Indonesia's most active volcanoes. More-or-less continuous explosive eruptions, sometimes accompanied by lava flows, occurred from 1933 until at least the mid-1990s, when routine observations were curtailed. During a major eruption in 1550, a lava flow filled in the strait between Halmahera and the north-flank cone of Gunung Mamuya. This complex volcano presents a broad, low profile with multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of the summit crater complex, contains a 700 x 570 m crater that has also been active during historical time. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AZh-eISy$ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPUnwZMHg$> Ebeko | Paramushir Island (Russia) | 50.686°N, 156.014°E | Summit elev. 1103 m KVERT reported that moderate activity at Ebeko was ongoing during 24 November-1 December. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions on 26 November and 1 December generated ash plumes that rose to 2.7 km (8,900 ft) a.s.l. and drifted NE. Ash fell in Severo-Kurilsk on 16 November. A thermal anomaly was identified in satellite images on 30 November; weather clouds prevented satellite views on the other days of the week. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted. Geologic Summary. The flat-topped summit of the central cone of Ebeko volcano, one of the most active in the Kuril Islands, occupies the northern end of Paramushir Island. Three summit craters located along a SSW-NNE line form Ebeko volcano proper, at the northern end of a complex of five volcanic cones. Blocky lava flows extend west from Ebeko and SE from the neighboring Nezametnyi cone. The eastern part of the southern crater contains strong solfataras and a large boiling spring. The central crater is filled by a lake about 20 m deep whose shores are lined with steaming solfataras; the northern crater lies across a narrow, low barrier from the central crater and contains a small, cold crescentic lake. Historical activity, recorded since the late-18th century, has been restricted to small-to-moderate explosive eruptions from the summit craters. Intense fumarolic activity occurs in the summit craters, on the outer flanks of the cone, and in lateral explosion craters. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1Aa1g2bBO$ <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVP8o7gRKQ$> Fuego | South-Central Guatemala | 14.473°N, 90.88°W | Summit elev. 3763 m INSIVUMEH reported that 4-12 explosions per hour were recorded at Fuego during 29 November-6 December, generating ash plumes that rose as high as 1.1 km above the crater rim. The ash plumes drifted as far as 30 km W, WSW, and SW causing daily ashfall in areas downwind including Morelia (9 km SW), Panimaché I and II (8 km SW), Santa SofÃa (12 km SW), El Porvenir (8 km ENE), Los Yucales (12 km SW), Sangre de Cristo (8 km WSW), El Porvenir (8 km ENE), San Pedro Yepocapa (8 km NW), Finca Palo Verde, Ojo de Agua, and Santa Emilia. Daily shock waves rattled structures in communities around the volcano. Daily block avalanches descended the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), Honda, Las Lajas (SE), El Jute (ESE), and Trinity drainages, often reaching vegetated areas. Strombolian explosions ejected incandescent material as high as 400 m above the summit on a few of the days. 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) https://urldefense.com/v3/__http://www.insivumeh.gob.gt/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AWz4LNJ-$ <https://urldefense.com/v3/__http://www.insivumeh.gob.gt/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPXe6KyuM$> Great Sitkin | Andreanof Islands (USA) | 52.076°N, 176.13°W | Summit elev. 1740 m AVO reported that slow lava effusion continued at Great Sitkin during 30 Novmeber-6 December. Lobes of lava advanced an additional 25-30 m along the S edge of the flow field and about 15 m SE, based on 25 November satellite images. Cloud cover prevented satellite and webcam observations during 30 Novmeber-6 December. Seismicity remained at low levels. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale). Geologic Summary. The Great Sitkin volcano forms much of the northern side of Great Sitkin Island. A younger parasitic volcano capped by a small, 0.8 x 1.2 km ice-filled summit caldera was constructed within a large late-Pleistocene or early Holocene scarp formed by massive edifice failure that truncated an ancestral volcano and produced a submarine debris avalanche. Deposits from this and an older debris avalanche from a source to the south cover a broad area of the ocean floor north of the volcano. The summit lies along the eastern rim of the younger collapse scarp. Deposits from an earlier caldera-forming eruption of unknown age cover the flanks of the island to a depth up to 6 m. The small younger caldera was partially filled by lava domes emplaced in 1945 and 1974, and five small older flank lava domes, two of which lie on the coastline, were constructed along northwest- and NNW-trending lines. Hot springs, mud pots, and fumaroles occur near the head of Big Fox Creek, south of the volcano. Historical eruptions have been recorded since the late-19th century. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AchITKOy$ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVP1JDB9KY$> Kerinci | Central Sumatra | 1.697°S, 101.264°E | Summit elev. 3800 m PVMBG reported that white steam-and-gas plumes rose as high as 300 m above Kerinciâ??s summit and drifted E almost daily during 29 November-5 December. Gray and white-to-brown plumes rose 100-300 m above the summit during 1-3 December. At 0822 on 6 December a gray-to-black ash plume rose about 700 m above the summit and drifted SW. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). The Alert Level remained at 2 (on a scale of 1-4), and the public was warned to remain outside of the 3-km exclusion zone. Geologic Summary. Gunung Kerinci in central Sumatra forms Indonesia's highest volcano and is one of the most active in Sumatra. It is capped by an unvegetated young summit cone that was constructed NE of an older crater remnant. There is a deep 600-m-wide summit crater often partially filled by a small crater lake that lies on the NE crater floor, opposite the SW-rim summit. The massive 13 x 25 km wide volcano towers 2400-3300 m above surrounding plains and is elongated in a N-S direction. Frequently active, Kerinci has been the source of numerous moderate explosive eruptions since its first recorded eruption in 1838. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AZh-eISy$ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPUnwZMHg$> Kilauea | Hawaiian Islands (USA) | 19.421°N, 155.287°W | Summit elev. 1222 m HVO reported that lava continued to effuse from a vent in the lower W wall of Kilaueaâ??s Halema`uma`u Crater during 30 November-6 December entering the lava lake and flowing onto the crater floor. The active part of the lake remained at a steady level most of the week, fluctuating only a few meters during 4-6 December. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale). Geologic Summary. Kilauea overlaps the E flank of the massive Mauna Loa shield volcano in the island of Hawaii. Eruptions are prominent in Polynesian legends; written documentation since 1820 records frequent summit and flank lava flow eruptions interspersed with periods of long-term lava lake activity at Halemaumau crater in the summit caldera until 1924. The 3 x 5 km caldera was formed in several stages about 1,500 years ago and during the 18th century; eruptions have also originated from the lengthy East and Southwest rift zones, which extend to the ocean in both directions. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1,100 years old; 70% of the surface is younger than 600 years. The long-term eruption from the East rift zone between 1983 and 2018 produced lava flows covering more than 100 km2, destroyed hundreds of houses, and added new coastline. Source: US Geological Survey Hawaiian Volcano Observatory (HVO) https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1ARudOhs9$ <https://urldefense.com/v3/__https://volcanoes.usgs.gov/observatories/hvo/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPD9sOc1s$> Late | Tonga Ridge | 18.806°S, 174.65°W | Summit elev. 540 m On 29 November Tonga Geological Services reported results from a recent visit to Late. The observers noted warmed ground surfaces, steam rising from fresh cracks, and vents at the summit. The features were too small to be identified in satellite images processed by VOLCAT (Volcanic Cloud Analysis Toolkit) software. They concluded that the features were the result of low-temperature hydrothermal activity driven by a shallow magma body at depth, and that the cracks were the result of past volcanic activity. There were no risks to local communities and mariners were advised to report any observable changes to the island. The Alert Levels all remained at Green (the lowest level on a four-color scale) for mariners, residents, and the aviation community. Geologic Summary. The 6-km-wide circular island of Late, along the Tofua volcanic arc about 55 km WSW of Vavau, contains a 400-m-wide, 150-m-deep summit crater with an ephemeral lake. The largely submerged basaltic-andesite to andesitic volcano rises 1,500 m from the sea floor, with its conical summit reaching 540 m above sea level. Cinder cones are found north of the summit crater, west and north of a semicircular plateau 100-150 m below the summit, and on the NW coast. A graben-like structure on the NE flank contains two large pit craters, the lower of which is partially filled by a saltwater lake. Eruptions from the NE-flank craters produced explosive activity and possible lava flows in 1790 and 1854. Source: Tonga Geological Services, Government of Tonga https://urldefense.com/v3/__https://www.facebook.com/tongageologicalservice__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1Acu57_Fm$ <https://urldefense.com/v3/__https://www.facebook.com/tongageologicalservice__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVP5w2FymQ$> Machin | Colombia | 4.487°N, 75.389°W | Summit elev. 2749 m On 2 December SGC reported that an increase in seismicity was detected at Cerro MachÃn beginning at 1123 on 2 December, with signals indicating rock fracturing. By 1320 a total of 393 signal were counted. The largest event, a M 4.5 recorded at 1236, was located 900 m SSW of the main dome at a depth of 3 km and was felt in Cajamarca (14 km WSW), Ibagué (17 km ESE), and in other municipalities of Tolima. The Alert Level remained at 3 (Yellow; the second lowest level on a four-color scale). Geologic Summary. The small Cerro MachÃn stratovolcano lies at the southern end of the Ruiz-Tolima massif about 20 km WNW of the city of Ibagué. A 3-km-wide caldera is breached to the south and contains three forested dacitic lava domes. Voluminous pyroclastic flows traveled up to 40 km away during eruptions in the mid-to-late Holocene, perhaps associated with formation of the caldera. Late-Holocene eruptions produced dacitic block-and-ash flows that traveled through the breach in the caldera rim to the west and south. The latest known eruption of took place about 800 years ago. Source: Servicio Geológico Colombiano (SGC) https://urldefense.com/v3/__https://www2.sgc.gov.co/volcanes/index.html__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AfRcan4M$ <https://urldefense.com/v3/__https://www2.sgc.gov.co/volcanes/index.html__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPUVRZPdQ$> Merapi | Central Java | 7.54°S, 110.446°E | Summit elev. 2910 m BPPTKG reported that the eruption at Merapi continued during 25 November-1 December and seismicity remained at high levels. The SW lava dome produced five lava avalanches that traveled as far as 1.5 km down the SW flank (upstream in the Kali Bebeng drainage). No significant morphological changes to the central and SW lava domes were evident. The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 3-7 km away from the summit based on location. Geologic Summary. Merapi, one of Indonesia's most active volcanoes, lies in one of the world's most densely populated areas and dominates the landscape immediately north of the major city of Yogyakarta. It is the youngest and southernmost of a volcanic chain extending NNW to Ungaran volcano. Growth of Old Merapi during the Pleistocene ended with major edifice collapse perhaps about 2,000 years ago, leaving a large arcuate scarp cutting the eroded older Batulawang volcano. Subsequent growth of the steep-sided Young Merapi edifice, its upper part unvegetated due to frequent activity, began SW of the earlier collapse scarp. Pyroclastic flows and lahars accompanying growth and collapse of the steep-sided active summit lava dome have devastated cultivated lands on the western-to-southern flanks and caused many fatalities. Source: Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG) https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1Ae2vYv-k$ <https://urldefense.com/v3/__http://www.merapi.bgl.esdm.go.id/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPKe6yw1c$> Nevado del Ruiz | Colombia | 4.892°N, 75.324°W | Summit elev. 5279 m Servicio Geológico Colombianoâ??s (SGC) reported that increased seismicity at Nevado del Ruiz began to be recorded at around 1016 on 2 December and increased further on 3 December. The signals indicated moving fluids within the volcanoâ??s conduit and were associated with gas-and-ash emissions seen from several municipalities in Tolima and Caldas. The gas-and-ash plumes generally rose less than 900 m above the summit and drifted SW but occasionally rose as high as 2.9 km. The Alert Level remained at 3 (Yellow; the second lowest level on a four-color scale). Geologic Summary. Nevado del Ruiz is a broad, glacier-covered volcano in central Colombia that covers more than 200 km2. Three major edifices, composed of andesitic and dacitic lavas and andesitic pyroclastics, have been constructed since the beginning of the Pleistocene. The modern cone consists of a broad cluster of lava domes built within the caldera of an older edifice. The 1-km-wide, 240-m-deep Arenas crater occupies the summit. The prominent La Olleta pyroclastic cone located on the SW flank may also have been active in historical time. Steep headwalls of massive landslides cut the flanks. Melting of its summit icecap during historical eruptions, which date back to the 16th century, has resulted in devastating lahars, including one in 1985 that was South America's deadliest eruption. Source: Servicio Geológico Colombiano (SGC) https://urldefense.com/v3/__https://www2.sgc.gov.co/volcanes/index.html__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AfRcan4M$ <https://urldefense.com/v3/__https://www2.sgc.gov.co/volcanes/index.html__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPUVRZPdQ$> Pavlof | Alaska Peninsula, Alaska | 55.417°N, 161.894°W | Summit elev. 2493 m AVO reported that a minor eruption at a vent on Pavlofâ??s upper E flank was ongoing during 29 November-6 December and nearly continuous seismic tremor was recorded. Daily small explosions were recorded through 3 December. Elevated surface temperatures were identified in satellite and webcam images during 29 November-1 December; weather clouds often prevented views during most of the week. A small plume was visible during 5-6 December; the ash content was unknown. The Volcano Alert Level remained at Watch (the second highest level on a four-level scale) and the Aviation Color Code remained at Orange (the second highest level on a four-color scale). Geologic Summary. The most active volcano of the Aleutian arc, Pavlof is a 2519-m-high Holocene stratovolcano that was constructed along a line of vents extending NE from the Emmons Lake caldera. Pavlof and its twin volcano to the NE, 2142-m-high Pavlof Sister, form a dramatic pair of symmetrical, glacier-covered stratovolcanoes that tower above Pavlof and Volcano bays. A third cone, Little Pavlof, is a smaller volcano on the SW flank of Pavlof volcano, near the rim of Emmons Lake caldera. Unlike Pavlof Sister, Pavlof has been frequently active in historical time, typically producing Strombolian to Vulcanian explosive eruptions from the summit vents and occasional lava flows. The active vents lie near the summit on the north and east sides. The largest historical eruption took place in 1911, at the end of a 5-year-long eruptive episode, when a fissure opened on the N flank, ejecting large blocks and issuing lava flows. Source: US Geological Survey Alaska Volcano Observatory (AVO) https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AchITKOy$ <https://urldefense.com/v3/__https://avo.alaska.edu/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVP1JDB9KY$> Popocatepetl | Mexico | 19.023°N, 98.622°W | Summit elev. 5393 m CENAPRED reported that there were 38-217 steam-and-gas emissions, sometimes containing minor amounts of ash, rising from Popocatépetl each day during 29 November-6 December. Weather clouds sometimes prevented visual observations of activity. Minor ashfall was reported in Amecameca (20 km NW), Cocotitlán, and Tlalmanalco (30 km NW) during 1-2 December, and in Tepetlixpa (20 km W) during 2-3 December, and in Atlautla (17 km W) and Ozumba (18 km W) during 5-6 December. The Alert Level remained at Yellow, Phase Two (the middle level on a three-color scale). Geologic Summary. Volcán Popocatépetl, whose name is the Aztec word for smoking mountain, rises 70 km SE of Mexico City to form North America's 2nd-highest volcano. The glacier-clad stratovolcano contains a steep-walled, 400 x 600 m wide crater. The generally symmetrical volcano is modified by the sharp-peaked Ventorrillo on the NW, a remnant of an earlier volcano. At least three previous major cones were destroyed by gravitational failure during the Pleistocene, producing massive debris-avalanche deposits covering broad areas to the south. The modern volcano was constructed south of the late-Pleistocene to Holocene El Fraile cone. Three major Plinian eruptions, the most recent of which took place about 800 CE, have occurred since the mid-Holocene, accompanied by pyroclastic flows and voluminous lahars that swept basins below the volcano. Frequent historical eruptions, first recorded in Aztec codices, have occurred since Pre-Columbian time. Sources: Centro Nacional de Prevencion de Desastres (CENAPRED) https://urldefense.com/v3/__https://www.gob.mx/cenapred__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AcNmPlvz$ <https://urldefense.com/v3/__https://www.gob.mx/cenapred__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVP-lGJ-DE$> Reventador | Ecuador | 0.077°S, 77.656°W | Summit elev. 3562 m IG described the ongoing eruption at Reventador as moderate during 29 November-6 December. Daily seismicity was characterized by explosions, long-period earthquakes, periods of harmonic tremor, and signals that indicated emissions. Gas, steam, and ash plumes, observed almost daily with webcams or reported by the Washington VAAC, rose as high as 1.9 km above the summit and drifted in multiple directions. Weather clouds occasionally prevented webcam and satellite views of the volcano. Active lava flows on the N and NE flanks were periodically visible in webcam views. Geologic Summary. Volcán El Reventador is the most frequently active of a chain of Ecuadorian volcanoes in the Cordillera Real, well east of the principal volcanic axis. The forested, dominantly andesitic stratovolcano has 4-km-wide avalanche scarp open to the E formed by edifice collapse. A young, unvegetated, cone rises from the amphitheater floor about 1,300 m to a height comparable to the rim. It has been the source of numerous lava flows as well as explosive eruptions visible from Quito, about 90 km ESE. Frequent lahars in this region of heavy rainfall have constructed a debris plain on the eastern floor of the scarp. The largest recorded eruption took place in 2002, producing a 17-km-high eruption column, pyroclastic flows that traveled up to 8 km, and lava flows from summit and flank vents. Source: Instituto GeofÃsico-Escuela Politécnica Nacional (IG) https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AUrrZx36$ <https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPxkbZdfA$> Santa Maria | Southwestern Guatemala | 14.757°N, 91.552°W | Summit elev. 3745 m INSIVUMEH reported that the eruption at Santa MarÃaâ??s Santiaguito lava-dome complex continued during 29 November-6 December. Effusion from Caliente cone fed lava flows that descended the San Isidro and El Tambor drainages on the W and SW flanks. Occasional block avalanches from the dome, and from both the ends and sides of the flows, descended the S, SW, and W flanks. The avalanches sometimes generated minor ash plumes that rose along their paths. Almost daily explosions produced gas-and-steam plumes with minor amounts of ash that rose as high as 800 m above the complex and sometimes drifted 5-8 km SW. Geologic Summary. Symmetrical, forest-covered Santa MarÃa volcano is part of a chain of large stratovolcanoes that rise above the Pacific coastal plain of Guatemala. The sharp-topped, conical profile is cut on the SW flank by a 1.5-km-wide crater. The oval-shaped crater extends from just below the summit to the lower flank, and was formed during a catastrophic eruption in 1902. The renowned Plinian eruption of 1902 that devastated much of SW Guatemala followed a long repose period after construction of the large basaltic-andesite stratovolcano. The massive dacitic Santiaguito lava-dome complex has been growing at the base of the 1902 crater since 1922. Compound dome growth at Santiaguito has occurred episodically from four vents, with activity progressing W towards the most recent, Caliente. Dome growth has been accompanied by almost continuous minor explosions, with periodic lava extrusion, larger explosions, pyroclastic flows, and lahars. Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH) https://urldefense.com/v3/__http://www.insivumeh.gob.gt/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AWz4LNJ-$ <https://urldefense.com/v3/__http://www.insivumeh.gob.gt/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPXe6KyuM$> Sheveluch | Central Kamchatka (Russia) | 56.653°N, 161.36°E | Summit elev. 3283 m KVERT reported that the ongoing eruption at Sheveluch during 24 November-1 December was generally characterized by explosions, hot avalanches, lava-dome extrusion, and strong fumarolic activity. A daily thermal anomaly was identified in satellite images. Collapses generated hot avalanches and ash plumes that drifted 90 km NE on 26 and 29 November, and 1 December. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on UTC times; specific events are in local time where noted. Geologic Summary. The high, isolated massif of Sheveluch volcano (also spelled Shiveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group. The 1,300 km3 andesitic volcano is one of Kamchatka's largest and most active volcanic structures, with at least 60 large eruptions during the Holocene. The summit of roughly 65,000-year-old Stary Shiveluch is truncated by a broad 9-km-wide late-Pleistocene caldera breached to the south. Many lava domes occur on its outer flanks. The Molodoy Shiveluch lava dome complex was constructed during the Holocene within the large open caldera; Holocene lava dome extrusion also took place on the flanks of Stary Shiveluch. Widespread tephra layers from these eruptions have provided valuable time markers for dating volcanic events in Kamchatka. Frequent collapses of dome complexes, most recently in 1964, have produced debris avalanches whose deposits cover much of the floor of the breached caldera. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1Aa1g2bBO$ <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVP8o7gRKQ$> Stromboli | Aeolian Islands (Italy) | 38.789°N, 15.213°E | Summit elev. 924 m INGV reported that starting at 1510 on 4 December lava overflowed Stromboliâ??s Area N (North Crater area) in conjunction with intense explosive activity. A strong explosion occurred at Area C-S (South-Central Crater area) at 1516, and at 1528 small collapses began shedding material onto the upper parts of the Sciara del Fuoco. At 1531 lava overflows and explosive activity likely collapsed part of a crater rim in Area N, resulting in pyroclastic flows that descended the Sciara del Fuoco. At 1619 a large pyroclastic flow descended the Sciara del Fuoco for several minutes and generated abundant ash clouds that temporarily blocked the view of the summit area. The pyroclastic flow went some distance over the water and caused a small tsunami. A lava flow was visible on the Sciara del Fuoco at 1640, and by about 1700 it had reached the coast. The lava flow originated from a fissure located just downslope of the N2 vent in the Area N. Abundant amounts of reddish-colored tephra fell in Ginostra, 1.5 km SW of summit. The Dipartimento della Protezione Civile raised the Alert Level to Orange (the second highest level on a four-color scale). Explosive activity continued at Area N. Lava effused from the vent at variable rates during 5-6 December, with higher rates corresponding to more intense explosive activity. Beginning at about 0830 on 5 December most explosions occurred at N2, with coarse material ejected a few tens of meters above the vent. Boulders rolled down the Sciara del Fuoco and caused diffuse ash plumes that quickly dispersed. Explosions at the summit were generally infrequent. Geologic Summary. Spectacular incandescent nighttime explosions at Stromboli have long attracted visitors to the "Lighthouse of the Mediterranean" in the NE Aeolian Islands. This volcano has lent its name to the frequent mild explosive activity that has characterized its eruptions throughout much of historical time. The small island is the emergent summit of a volcano that grew in two main eruptive cycles, the last of which formed the western portion of the island. The Neostromboli eruptive period took place between about 13,000 and 5,000 years ago. The active summit vents are located at the head of the Sciara del Fuoco, a prominent scarp that formed about 5,000 years ago due to a series of slope failures which extends to below sea level. The modern volcano has been constructed within this scarp, which funnels pyroclastic ejecta and lava flows to the NW. Essentially continuous mild Strombolian explosions, sometimes accompanied by lava flows, have been recorded for more than a millennium. Source: Sezione di Catania - Osservatorio Etneo (INGV) https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1ASMwYZhU$ <https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVP2VckjuA$> Suwanosejima | Ryukyu Islands (Japan) | 29.638°N, 129.714°E | Summit elev. 796 m JMA reported that the eruption at Suwanosejima's Ontake Crater continued during 28 November-5 December and crater incandescence was visible nightly. No explosions were recorded. Eruption plumes rose as high as 1.8 km above the crater rim and blocks were ejected as far as 300 m from the vent. Ashfall was occasionally reported in Toshima village (3.5 km SSW). The Alert Level remained at 3 (on a 5-level scale), and residents were warned to stay 2 km away from the crater. Geologic Summary. The 8-km-long island of Suwanosejima in the northern Ryukyu Islands consists of an andesitic stratovolcano with two historically active summit craters. The summit is truncated by a large breached crater extending to the sea on the east flank that was formed by edifice collapse. One of Japan's most frequently active volcanoes, it was in a state of intermittent Strombolian activity from Otake, the NE summit crater, between 1949 and 1996, after which periods of inactivity lengthened. The largest recorded eruption took place in 1813-14, when thick scoria deposits blanketed residential areas, and the SW crater produced two lava flows that reached the western coast. At the end of the eruption the summit of Otake collapsed, forming a large debris avalanche and creating the open Sakuchi caldera, which extends to the eastern coast. The island remained uninhabited for about 70 years after the 1813-1814 eruption. Lava flows reached the eastern coast of the island in 1884. Only about 50 people live on the island. Source: Japan Meteorological Agency (JMA) https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!Y6B4df2lFpgNEx0NisdCs4BfC-uvA58sd77r55sBgZ0rDZxcPG7LlspqC-hfnGNC_6PSpIo1AW3qIbAG$ <https://urldefense.com/v3/__http://www.jma.go.jp/jma/__;!!IKRxdwAv5BmarQ!Z7iO87qb-O42F4nsySysziVaWKaxid8hhvOqCkE62rnvlab_-vaZjz70KGWcPihfznVPB4luDeE$> 5-5-5-5-5-5-5-5-5-5-5-5-5-5 ============================================================== 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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