4-4-4-4-4-4-4-4-4-4-4-4-4 From: "Marlow, JoAnna" <MarlowJ@xxxxxx> Smithsonian / USGS Weekly Volcanic Activity Report 31 July-6 August 2024 Sally Sennert - Weekly Report Editor (kuhns@xxxxxx) Zac Hastings - contributor (zhastings@xxxxxxxx) JoAnna Marlow - contributor (jmarlow@xxxxxxxx) URL: https://volcano.si.edu/reports_weekly.cfm <https://urldefense.com/v3/__https://volcano.si.edu/reports_weekly.cfm__;!!IKRxdwAv5BmarQ!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlPqGAI2QA$> New Activity/Unrest: Bezymianny, Central Kamchatka (Russia) | Etna, Sicily (Italy) | Karymsky, Eastern Kamchatka (Russia) Ongoing Activity: Aira, Kyushu (Japan) | Dukono, Halmahera | Ebeko, Paramushir Island (Russia) | Fuego, South-Central Guatemala | Great Sitkin, Andreanof Islands (USA) | Ibu, Halmahera | Lewotobi, Flores Island | Merapi, Central Java | Popocatepetl, Mexico | Santa Maria, Southwestern Guatemala | Semeru, Eastern Java | Sheveluch, Central Kamchatka (Russia) | Suwanosejima, Ryukyu Islands (Japan) | Taal, Luzon (Philippines) | Tungurahua, Ecuador The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday, these reports are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of all of Earth's volcanoes erupting during the week, but rather a summary of activity at volcanoes that meet criteria discussed in detail in the "Criteria and Disclaimers" section. Carefully reviewed, detailed reports about recent activity are published in issues of the Bulletin of the Global Volcanism Network. Note that many news agencies do not archive the articles they post on the Internet, and therefore the links to some sources may not be active. To obtain information about the cited articles that are no longer available on the Internet contact the source. New Activity/Unrest Bezymianny | Central Kamchatka (Russia) | 55.972°N, 160.595°E | Summit elev. 2882 m The Kamchatka Volcanic Eruption Response Team (KVERT) reported that the effusive eruption at Bezymianny continued during 25 July-1 August. A notable thermal anomaly was observed over the volcano in satellite imagery during the reporting period. The Aviation Color Code remained at Yellow (the second 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!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlPNsLgnQQ$> Etna | Sicily (Italy) | 37.748°N, 14.999°E | Summit elev. 3357 m INGV reported that activity at Etnaâ??s summit craters continued during 29 July-4 August. On 29 July ongoing Strombolian activity at the Voragine crater generated a small ash emission that quickly dispersed from the summit area. Around 0408 on 4 August the Strombolian activity at Voragine crater began to increase in intensity and frequency, with volcanic tremor amplitude reaching very high levels around 0430 and increasing further by 0520 when activity transitioned to lava fountains. At 0445 the Aviation Color Code was raised from Orange to Red, though the ash cloud height could not be estimated. The fountains produced an SO2-rich eruption plume that by 0542 had reached about 6.5 km above the summit (to about 10 km a.s.l.) and was drifting SE; significant tephra (ash and lapilli) fell towards the E, affecting areas such as Fleri (14 km SE), Fornazzo (10.5 km E), Zafferana (11 km SE), Milo (11 km ESE), Santa Venerina (14 km SE), Giarre (17 km E), Riposto (18 km E), Stazzo (20 km SE), Torre Archirafi (20 km E), San Giovanni La Punta (20 km SSE), Viagrande (17 km SE), Aci Sant'Antonio, Aci Catena (20 km SE), Aci Castello (23 km SE), Aci Trezza (23 km SE), and Acireale (20 km SE). An ash advisory at 1058 noted that a second plume with a high ash concentration had reached 6.2 km a.s.l., and both it and the higher plume were drifting SSE. The high tremor amplitude decreased after 0910, explosive activity decreased over the next few hours, and at 1318 the Aviation Color Code was lowered from Red to Orange, though there were still sporadic emissions with ashfall confined to the summit area. Operations at the Aeroporto de Catania were reduced to six arrivals per hour during part of this period of elevated activity. During the lava fountaining, INGV observers noted that lava from Voragine had completely filled the Bocca Nuova (BN) crater, resulting in lava overflows from its W rim. There was an also an active flow moving NW to an elevation of about 3,000 m, and a flow was present between the Voragine and BN 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. Sources:Sezione di Catania - Osservatorio Etneo (INGV) http://www.ct.ingv.it/ <https://urldefense.com/v3/__http://www.ct.ingv.it/__;!!IKRxdwAv5BmarQ!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlOtIc464g$> ; Toulouse Volcanic Ash Advisory Centre (VAAC) http://vaac.meteo.fr/ <https://urldefense.com/v3/__http://vaac.meteo.fr/__;!!IKRxdwAv5BmarQ!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlOVCYVvIQ$> ; Aeroporto di Catania http://www.aeroporto.catania.it/ <https://urldefense.com/v3/__http://www.aeroporto.catania.it/__;!!IKRxdwAv5BmarQ!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlPDUPWR8Q$> Karymsky | Eastern Kamchatka (Russia) | 54.049°N, 159.443°E | Summit elev. 1513 m The Kamchatka Volcanic Eruption Response Team (KVERT) reported that moderate levels of activity continued at Karymsky during 25 July-1 August. Satellite data analyzed by KVERT showed a thermal anomaly over the volcano during 27-28 and 30 July; weather clouds prevented observations in satellite images on the other days. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates are reported in UTC; specific events are in local time where noted. Geologic Summary. Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed during the early Holocene. The caldera cuts the south side of the Pleistocene Dvor volcano and is located outside the north margin of the large mid-Pleistocene Polovinka caldera, which contains the smaller Akademia Nauk and Odnoboky calderas. Most seismicity preceding Karymsky eruptions originated beneath Akademia Nauk caldera, located immediately south. The caldera enclosing Karymsky formed about 7600-7700 radiocarbon years ago; construction of the stratovolcano began about 2000 years later. The latest eruptive period began about 500 years ago, following a 2300-year quiescence. Much of the cone is mantled by lava flows less than 200 years old. Historical eruptions have been vulcanian or vulcanian-strombolian with moderate explosive activity and occasional lava flows from the summit crater. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlPNsLgnQQ$> Ongoing Activity Aira | Kyushu (Japan) | 31.5772°N, 130.6589°E | Summit elev. 1117 m JMA reported ongoing eruptive activity at Minamidake Crater (Aira Calderaâ??s Sakurajima volcano) during 29 July-6 August. Nighttime crater incandescence was visible in webcam images. An explosion at 1646 on 29 July generated an ash plume that rose 4.4 km above the crater, and large blocks were ejected about 1,400 m WNW from the crater. An eruption at 0559 on 3 August generated an ash plume that rose 1,500 m above the summit. On 6 August multiple explosions generated ash plumes that rose as high as 3,000 m above the crater and drifted SW. Large blocks were ejected 1,300-1,700 m WNW from the crater. 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!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlPh-c7sOg$> Dukono | Halmahera | 1.6992°N, 127.8783°E | Summit elev. 1273 m PVMBG reported that the eruption at Dukono was ongoing during 31 July-6 August. White emissions rose 100-600 m above the summit and drifted W and NW on 31 July. Gray-and-white emissions rose 100-900 m above the summit and drifted SW, W, and NW during 2-6 August. The Alert Level remained at Level 2 (on a scale of 1-4), and the public was warned to remain outside of the 3-km exclusion zone. Geologic Summary. Reports from this remote volcano in northernmost Halmahera are rare, but Dukono has been one of Indonesia's most active volcanoes. More-or-less continuous explosive eruptions, sometimes accompanied by lava flows, have occurred since 1933. During a major eruption in 1550 CE, a lava flow filled in the strait between Halmahera and the N-flank Gunung Mamuya cone. This complex volcano presents a broad, low profile with multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of the summit crater complex, contains a 700 x 570 m crater that has also been active during historical time. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlMGxDNwwA$> Ebeko | Paramushir Island (Russia) | 50.686°N, 156.014°E | Summit elev. 1103 m The Kamchatka Volcanic Eruption Response Team (KVERT) reported that moderate explosive activity continued at Ebeko during 25 July-1 August. Webcam images captured explosions between 26 and 29 July, as well as on 1 August, which generated ash plumes that rose to 3 km a.s.l., drifting SE from 26 to 28 July and NE on 29 July and 1 August. A thermal anomaly was observed over the volcano on 26 July in satellite images analyzed by KVERT; weather clouds prevented views on the other days. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates are reported in UTC; specific events are in local time where noted. Geologic Summary. The flat-topped summit of the central cone of Ebeko volcano, one of the most active in the Kuril Islands, occupies the northern end of Paramushir Island. Three summit craters located along a SSW-NNE line form Ebeko volcano proper, at the northern end of a complex of five volcanic cones. Blocky lava flows extend west from Ebeko and SE from the neighboring Nezametnyi cone. The eastern part of the southern crater contains strong solfataras and a large boiling spring. The central crater is filled by a lake about 20 m deep whose shores are lined with steaming solfataras; the northern crater lies across a narrow, low barrier from the central crater and contains a small, cold crescentic lake. Historical activity, recorded since the late-18th century, has been restricted to small-to-moderate explosive eruptions from the summit craters. Intense fumarolic activity occurs in the summit craters, on the outer flanks of the cone, and in lateral explosion craters. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php <https://urldefense.com/v3/__http://www.kscnet.ru/ivs/kvert/index_eng.php__;!!IKRxdwAv5BmarQ!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlPNsLgnQQ$> Fuego | South-Central Guatemala | 14.473°N, 90.88°W | Summit elev. 3763 m Instituto Nacional de SismologÃa, Vulcanologia, Meteorologia e HidrologÃa (INSIVUMEH) reported that eruptive activity continued at Fuego during 31 July-6 August. Daily explosions were recorded by the seismic network, ranging from 2 to 10 explosions per hour. The explosions generated gas-and-ash plumes that rose as high as 4.8 km above the crater rim and drifted as far as 30 km SW and W. The explosions produced block avalanches that descended the Ceniza (SSW), Santa Teresa (W), Seca (W), Taniluyá (SW), and Las Lajas (SE) drainages. On most days the explosions also ejected incandescent material 100-300 m above the summit, which was observed at night and early morning. The activity was often accompanied by weak-to-moderate rumbling sounds, shock waves, and sounds similar to a turbine engine lasting a few minutes at a time. Ashfall was reported on 31 July and 1 August in areas downwind including Panimaché I and II (8 km SW), Finca Paloverde (10 km SW), El Porvenir (10 km S), Santa Sofia (12 km SW), Sangre de Cristo (10 km SW), Morelia (10 km SW), Los Yucales (12 km SW), and other nearby communities. Ashfall was forecast for areas downwind on some of the other 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) http://www.insivumeh.gob.gt/ <https://urldefense.com/v3/__http://www.insivumeh.gob.gt/__;!!IKRxdwAv5BmarQ!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlPA_DffpQ$> Great Sitkin | Andreanof Islands (USA) | 52.076°N, 176.13°W | Summit elev. 1740 m AVO reported that slow lava effusion in Great Sitkinâ??s summit crater continued during 31 July-6 August. The continued growth of the active flow was confirmed by satellite. Seismicity was low with few small daily earthquakes and rockfall signals. Weakly elevated surface temperatures and steam emissions from the growing dome were occasionally visible. Weather clouds often obscured or partially obscured satellite and webcam views. 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!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlMYoLj_tg$> Ibu | Halmahera | 1.488°N, 127.63°E | Summit elev. 1325 m Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that explosive activity continued at Ibu during 31 July-6 August. Emissions were observed daily; white plumes rose as high as 700 m above the summit and gray plumes produced by explosion events rose as high as 1.5 km above the summit. Seismicity included harmonic tremor episodes, volcanic earthquakes, frequent gas emission signals, and 43-108 daily explosion events. Ashfall was reported at the Ibu Volcano Observation Post (9 km W) on 6 August. The Alert Level remained at 3 (the third level on a four-level scale) and the public was advised to stay 4 km away from the active crater and 5 km away from the N crater wall opening. Geologic Summary. The truncated summit of Gunung Ibu stratovolcano along the NW coast of Halmahera Island has large nested summit craters. The inner crater, 1 km wide and 400 m deep, has contained several small crater lakes. The 1.2-km-wide outer crater is breached on the N, creating a steep-walled valley. A large cone grew ENE of the summit, and a smaller one to the WSW has fed a lava flow down the W flank. A group of maars is located below the N and W flanks. The first observed and recorded eruption was a small explosion from the summit crater in 1911. Eruptive activity began again in December 1998, producing a lava dome that eventually covered much of the floor of the inner summit crater along with ongoing explosive ash emissions. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlMGxDNwwA$> Lewotobi | Flores Island | 8.542°S, 122.775°E | Summit elev. 1703 m Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Lewotobi Laki-laki continued during 31 July-6 August. Emissions were observed daily, with white and gray plumes reaching heights of 50 to 1,200 m above the crater rim. Seismicity included frequent gas emission signals, harmonic tremor episodes, volcanic earthquakes, rockfall events, low-frequency (LF) earthquakes, and 4-7 daily explosive events. The Alert Level remained at 3 (the third level on a four-level scale) and the public was warned to stay outside of the exclusion zone, defined as a 3-km radius around both Laki-laki and Perempuan craters, 4 km to the NNW and SSE of Laki-laki. Geologic Summary. The Lewotobi edifice in eastern Flores Island is composed of the two adjacent Lewotobi Laki-laki and Lewotobi Perempuan stratovolcanoes (the "husband and wife"). Their summits are less than 2 km apart along a NW-SE line. The conical Laki-laki to the NW has been frequently active during the 19th and 20th centuries, while the taller and broader Perempuan has had observed eruptions in 1921 and 1935. Small lava domes have grown during the 20th century in both of the summit craters, which are open to the north. A prominent cone, Iliwokar, occurs on the E flank of Perampuan. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlMGxDNwwA$> Merapi | Central Java | 7.54°S, 110.446°E | Summit elev. 2910 m BPPTKG reported that the eruption at Merapi (on Java) continued during 26 July-2 August. The SW lava dome generated 148 lava avalanches that traveled as far as 1.8 km down the upper part of the Bebeng drainage. One pyroclastic flow also traveled as far as 1 km down the Bebeng drainage. Ten times the lava avalanches were heard from the Kaliurang and Babadan observation posts. Morphological changes to the SW lava dome were due to continuing effusion and collapses of material, but the dome at the main crater remained mostly unchanged. The volume estimates of the two domes did not change from the previous week at 2,538,700 cubic meters (SW dome) and 2,360,700 cubic meters (main dome). 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!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlNN_IJJCg$> Popocatepetl | Mexico | 19.023°N, 98.622°W | Summit elev. 5393 m Centro Nacional de Prevención de Desastres (CENAPRED) reported that eruptive activity continued at Popocatépetl during 30 July-6 August. Daily activity consisted of 30-90 long-period (LP) events that were accompanied by emissions of gas, steam, and sometimes small quantities of ash. A total of 16 minutes of high-frequency, very low-amplitude tremor was registered during 30-31 July, and 169 minutes (approximately 2.8 hours) of harmonic, very low-amplitude tremor was recorded during 30 July-5 August. Additionally, a M1.4 volcano-tectonic (VT) earthquake was registered on 30 July at 2108. On 4 August at 0939, a plume with low ash content reached 800 m above the summit and drifted W; the Washington Volcanic Ash Advisory Center (VAAC) reported that satellite images showed that the ash had dissipated by 2146 later that night. Continuous gas-and-steam emissions were observed on some mornings; plumes dispersed toward the NW, WNW, and W. The Alert Level remained at Yellow, Phase Two (the middle level on a three-color scale) and the public was warned to stay at least 12 km away from the crater. Geologic Summary. Volcán Popocatépetl, whose name is the Aztec word for smoking mountain, rises 70 km SE of Mexico City to form North America's 2nd-highest volcano. The glacier-clad stratovolcano contains a steep-walled, 400 x 600 m wide crater. The generally symmetrical volcano is modified by the sharp-peaked Ventorrillo on the NW, a remnant of an earlier volcano. At least three previous major cones were destroyed by gravitational failure during the Pleistocene, producing massive debris-avalanche deposits covering broad areas to the south. The modern volcano was constructed south of the late-Pleistocene to Holocene El Fraile cone. Three major Plinian eruptions, the most recent of which took place about 800 CE, have occurred since the mid-Holocene, accompanied by pyroclastic flows and voluminous lahars that swept basins below the volcano. Frequent historical eruptions, first recorded in Aztec codices, have occurred since Pre-Columbian time. Sources: Centro Nacional de Prevencion de Desastres (CENAPRED) https://www.gob.mx/cenapred <https://urldefense.com/v3/__https://www.gob.mx/cenapred__;!!IKRxdwAv5BmarQ!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlN7c177zg$> ; Washington Volcanic Ash Advisory Center (VAAC) http://www.ssd.noaa.gov/VAAC/messages.html <https://urldefense.com/v3/__http://www.ssd.noaa.gov/VAAC/messages.html__;!!IKRxdwAv5BmarQ!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlPUOCxjoA$> Santa Maria | Southwestern Guatemala | 14.757°N, 91.552°W | Summit elev. 3745 m Instituto Nacional de SismologÃa, Vulcanologia, Meteorologia e HidrologÃa (INSIVUMEH) reported that eruptive activity continued at Santa Mariaâ??s Santiaguito lava-dome complex during 31 July-6 August with lava extrusion, block collapses, and avalanches at the Caliente dome complex. The continuous effusion of blocky lava produced block avalanches on the domeâ??s flanks and occasional short pyroclastic flows that descended multiple flanks. During most nights and early mornings incandescence was visible around Caliente dome, along the upper parts of the lava flow, and at several locations on other flanks. Daily explosions (a few per hour on most days) generated gas-and-ash plumes that rose 400-800 m above the summit and drifted NW, W, and SW. Ashfall was reported in San Marcos (8 km SW) and Loma Linda Palajunoj (7 km SW) on 1 and 4 August. 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!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlPA_DffpQ$> Semeru | Eastern Java | 8.108°S, 112.922°E | Summit elev. 3657 m PVMBG reported that eruptive activity continued at Semeru during 31 July-6 August. On 3 August white emissions rose about 100 m above the summit and drifted N, S, and SW. Daily eruptive events, several per day as recorded by the seismic network, generated white and gray emissions that rose 500-1,000 m above the summit and drifted several directions, though plumes were not always visually confirmed. The Alert Level remained at 2 (the second lowest level on a scale of 1-4). The public was warned to stay at least 5 km away from the summit in all directions, 13 km from the summit to the SE, 500 m from the banks of the Kobokan drainage as far as 17 km from the summit, and to avoid other drainages including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards. Geologic Summary. Semeru, the highest volcano on Java, and one of its most active, lies at the southern end of a volcanic massif extending north to the Tengger caldera. The steep-sided volcano, also referred to as Mahameru (Great Mountain), rises above coastal plains to the south. Gunung Semeru was constructed south of the overlapping Ajek-ajek and Jambangan calderas. A line of lake-filled maars was constructed along a N-S trend cutting through the summit, and cinder cones and lava domes occupy the eastern and NE flanks. Summit topography is complicated by the shifting of craters from NW to SE. Frequent 19th and 20th century eruptions were dominated by small-to-moderate explosions from the summit crater, with occasional lava flows and larger explosive eruptions accompanied by pyroclastic flows that have reached the lower flanks of the volcano. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ <https://urldefense.com/v3/__http://vsi.esdm.go.id/__;!!IKRxdwAv5BmarQ!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlMGxDNwwA$> Sheveluch | Central Kamchatka (Russia) | 56.653°N, 161.36°E | Summit elev. 3283 m The Kamchatka Volcanic Eruption Response Team (KVERT) reported that eruptive activity at Sheveluch intensified during 25 July-1 August. Vigorous degassing activity accompanied the effusive eruption in the N area of the crater of Young Sheveluch, as well as the growth of the "300 years of RAS" lava dome on the SW flank of Old Sheveluch. Thermal anomalies were observed over both areas in satellite images analyzed by KVERT on 25, 28, and 30-31 July, and 1 August. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates are reported in UTC; 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!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlPNsLgnQQ$> Suwanosejima | Ryukyu Islands (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 29 July-5 August. Crater incandescence was observed nightly in webcam images. Eruption events at 1907 and 2339 on 2 August produced ash plumes that rose 1 km above the crater rim and drifted toward the SE, as well as ejected large ballistic projectiles as far as 400 m from the center of the crater. Rumbling was reported by the Suwanosejima Branch of the Toshima Village Office (3.5 km SSW). Tremor was registered at the same time as the eruption events. 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!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlPh-c7sOg$> Taal | Luzon (Philippines) | 14.0106°N, 120.9975°E | Summit elev. 311 m The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported daily emissions and phreatic eruptions at Taalâ??s Main Crater during 31 July-6 August. There were five phreatic eruptions recorded, each lasting between 1 and 5 minutes. On 31 July diffuse emissions rose 500 m above the crater rim and drifted NE. During 1-6 August moderately dense to dense emissions rose as high as 2.4 km above the crater rim and drifted in several directions. The SO2 concentration was measured at 3,309 tonnes per day (t/d) on 2 August and 4,666 t/d on 5 August. The Alert Level remained at 1 (on a scale of 0-5), and PHIVOLCS reminded the public that the entire Taal Volcano Island was a Permanent Danger Zone (PDZ) and to take extra precaution around Main Crater and along the Daang Kastila fissure. Geologic Summary. Taal is one of the most active volcanoes in the Philippines and has produced some powerful eruptions. The 15 x 20 km Talisay (Taal) caldera is largely filled by Lake Taal, whose 267 km2 surface lies only 3 m above sea level. The maximum depth of the lake is 160 m, with several submerged eruptive centers. The 5-km-wide Volcano Island in north-central Lake Taal is the location of all observed eruptions. The island is composed of coalescing small stratovolcanoes, tuff rings, and scoria cones. Powerful pyroclastic flows and surges have caused many fatalities. Source: Philippine Institute of Volcanology and Seismology (PHIVOLCS) http://www.phivolcs.dost.gov.ph/ <https://urldefense.com/v3/__http://www.phivolcs.dost.gov.ph/__;!!IKRxdwAv5BmarQ!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlMJ_tcCBQ$> Tungurahua | Ecuador | 1.467°S, 78.442°W | Summit elev. 5023 m Instituto GeofÃsico-Escuela Politécnica Nacional (IG-EPN) reported that surveillance cameras showed that ash previously deposited on the NW flank of Tungurahua became resuspended by strong winds on 3 August at around 1252. Additionally, IG-EPN reminded the public that activity levels at Tungurahua remained low. Geologic Summary. Tungurahua, a steep-sided andesitic-dacitic stratovolcano that towers more than 3 km above its northern base, is one of Ecuador's most active volcanoes. Three major edifices have been sequentially constructed since the mid-Pleistocene over a basement of metamorphic rocks. Tungurahua II was built within the past 14,000 years following the collapse of the initial edifice. Tungurahua II collapsed about 3,000 years ago and produced a large debris-avalanche deposit to the west. The modern glacier-capped stratovolcano (Tungurahua III) was constructed within the landslide scarp. Historical eruptions have all originated from the summit crater, accompanied by strong explosions and sometimes by pyroclastic flows and lava flows that reached populated areas at the volcano's base. Prior to a long-term eruption beginning in 1999 that caused the temporary evacuation of the city of Baños at the foot of the volcano, the last major eruption had occurred from 1916 to 1918, although minor activity continued until 1925. Source: Instituto GeofÃsico-Escuela Politécnica Nacional (IG-EPN) http://www.igepn.edu.ec/ <https://urldefense.com/v3/__http://www.igepn.edu.ec/__;!!IKRxdwAv5BmarQ!c5Cc2sSRjsq3CK_XMaGmAt9hTeEQgbsW_CA2EpI2MlTCbpUyURktRiWQ8oImhzmY3SSVRMZP_9LDsm89ZlPbKoN9tQ$> 4-4-4-4-4-4-4-4-4-4-4-4-4 ============================================================== Volcano Listserv is a collaborative venture among Arizona State University (ASU), Portland State University (PSU), the Global Volcanism Program (GVP) of the Smithsonian Institution's National Museum of Natural History, and the International Association for Volcanology and Chemistry of the Earth's Interior (IAVCEI). 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