8-8-8-8-8-8-8-8-8-8-8-8-8 From: "Kuhn, Sally" <KUHNS@xxxxxx> Smithsonian / USGS Weekly Volcanic Activity Report 18-24 June 2025 Sally Sennert - Weekly Report Editor (kuhns@xxxxxx) URL: https://volcano.si.edu/reports_weekly.cfm New Activity/Unrest: Kirishimayama, Japan | Kuchinoerabujima, Japan | Lewotobi, Indonesia | Miyakejima, Japan Ongoing Activity: Aira, Japan | Awu, Indonesia | Dukono, Indonesia | Etna, Italy | Great Sitkin, United States | Home Reef, Tonga | Ibu, Indonesia | Karymsky, Russia | Kilauea, United States | Klyuchevskoy, Russia | Lascar, Chile | Lewotolok, Indonesia | Marapi, Indonesia | Merapi, Indonesia | Nevado del Ruiz, Colombia | Poas, Costa Rica | Raung, Indonesia | Semeru, Indonesia | Sheveluch, Russia | Suwanosejima, 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 Kirishimayama | Japan | 31.934°N, 130.862°E | Summit elev. 1700 m The Japan Meteorological Agency (JMA) reported that an eruption occurred at Shinmoedake (Shinmoe peak, a stratovolcano of the Kirishimayama volcano group) on 22 June, the first eruption since 27 June 2018. The number of volcanic earthquakes with epicenters directly beneath Shinmoedake had been fluctuating since late October 2024 but began to increase starting around 13 June. Another increase occurred at around 2100 on 21 June, and volcanic tremor increased on 22 June. An eruption detected during 1637-1755 on 22 June produced an ash plume that rose 500 m above the crater rim and drifted E. Ashfall was confirmed in a wide area to the NE that included Takaharu Town, Kobayashi City, Miyazaki City, Kunitomi Town, Saito City, and Shintomi Town in Miyazaki Prefecture. A large amount of ashfall in Hirohara, Takaharu-cho, Miyazaki Prefecture obscured the white lines on the roadway. Sulfur dioxide emissions averaged 4,000 tons per day on 23 June; no emissions were detected on 15 May during the last measurement. On 23 June the Alert Level was raised to 3 (on a 5-level scale) and the public was warned to exercise caution within 3 km from Shinmoedake Crater. Geologic Summary. Kirishimayama is a large group of more than 20 Quaternary volcanoes located north of Kagoshima Bay. The late-Pleistocene to Holocene dominantly andesitic group consists of stratovolcanoes, pyroclastic cones, maars, and underlying shield volcanoes located over an area of 20 x 30 km. The larger stratovolcanoes are scattered throughout the field, with the centrally located Karakunidake being the highest. Onamiike and Miike, the two largest maars, are located SW of Karakunidake and at its far eastern end, respectively. Holocene eruptions have been concentrated along an E-W line of vents from Miike to Ohachi, and at Shinmoedake to the NE. Frequent small-to-moderate explosive eruptions have been recorded since the 8th century. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ Kuchinoerabujima | Japan | 30.443°N, 130.217°E | Summit elev. 657 m The Japan Meteorological Agency (JMA) reported that the number of shallow volcanic earthquakes increased beneath an area near Kuchinoerabujimaâ??s Furudake Crater in April and continued to increase. Sulfur dioxide emissions were low, averaging 20-80 tons per day since April, and there were days in April where the emissions were below detectable limits. Deformation data indicated ongoing inflation. Volcanic earthquakes with somewhat large amplitudes were occasionally recorded in May by the seismic network. There were many (135) volcanic earthquakes recorded during 2-11 June. No changes to geothermal areas located in and around both Shindake and Furudake craters were observed during a field survey conducted on 11 June. The Alert Level was raised to 3 (on a scale of 1-5) at 2100 on 11 June; the public was warned that ejected blocks may land within 2 km of both craters, and pyroclastic flows may affect areas between Shindake Crater and the coast. Geologic Summary. A group of young stratovolcanoes forms the eastern end of the irregularly shaped island of Kuchinoerabujima in the northern Ryukyu Islands, 15 km W of Yakushima. The Furudake, Shindake, and Noikeyama cones were erupted from south to north, respectively, forming a composite cone with multiple craters. All historical eruptions have occurred from Shindake, although a lava flow from the S flank of Furudake that reached the coast has a very fresh morphology. Frequent explosive eruptions have taken place from Shindake since 1840; the largest of these was in December 1933. Several villages on the 4 x 12 km island are located within a few kilometers of the active crater and have suffered damage from eruptions. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ Lewotobi | Indonesia | 8.542°S, 122.775°E | Summit elev. 1703 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity continued at Lewotobi Laki-laki during 18-25 June, after the explosive eruption on 17 June. At 0318 and 0641 on 18 June ash plumes rose 1 km above the summit and drifted N and NE. Visual observations of eruptive events recorded at 1229 and 2212 later that day, and at 0922 and 1008 on 19 June, were obscured by weather conditions; incandescence at the summit was visible in a webcam image at 2223 on 18 June. Dense gray ash plumes rose as high as 2 km above the summit and drifted S and SW at 2213 and 2231 on 20 June and at 0014 and 0024 on 21 June. Webcam images taken near midnight showed incandescent material being ejected above the summit and onto the upper flanks. An eruptive event was recorded at 1440 on 23 June but weather conditions again obscured views. According to news reports the number of evacuees totaled 4,954 on 19 June and 4,007 as of 21 June. The Alert Level remained at 4 (on a scale of 1-4) and the public was warned to stay 7 km away from the center of Laki-laki and 8 km in a semicircle clockwise from the SW to the NE. Geologic Summary. The Lewotobi edifice in eastern Flores Island is composed of the two adjacent Lewotobi Laki-laki and Lewotobi Perempuan stratovolcanoes (the "husband and wife"). Their summits are less than 2 km apart along a NW-SE line. The conical Laki-laki to the NW has been frequently active during the 19th and 20th centuries, while the taller and broader Perempuan has had observed eruptions in 1921 and 1935. Small lava domes have grown during the 20th century in both of the summit craters, which are open to the north. A prominent cone, Iliwokar, occurs on the E flank of Perampuan. Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/; Antara News https://www.antaranews.com/berita/4916141/pertamina-salurkan-bantuan-untuk-korban-erupsi-gunung-lewotobi ; Antara News https://www.antaranews.com/berita/4912149/mensos-dirikan-8-dapur-umum-bagi-4954-korban-gunung-lewotobi Miyakejima | Japan | 34.094°N, 139.526°E | Summit elev. 775 m The Japan Meteorological Agency (JMA) reported that the number of small volcanic earthquakes at Miyakejima decreased after a peak on 17 June that led to an Alert Level change. On 17 June the number of small volcanic earthquakes with epicenters directly below the summit crater totaled 59, and uplift near the summit was detected in tiltmeter data. During 18-23 June the number of daily earthquakes decreased to 0-4 earthquakes per day and no changes in tilt were detected after 18 June. The Alert Level remained at 2 (on a 5-level scale) and the public was warned to be cautious in areas inside the Oyama Ring Road. Geologic Summary. The circular, 8-km-wide island of Miyakejima forms a low-angle stratovolcano that rises about 1,100 m from the sea floor in the northern Izu Islands about 200 km SSW of Tokyo. The basaltic volcano is truncated by small summit calderas, one of which, 3.5 km wide, was formed during a major eruption about 2,500 years ago. Numerous craters and vents, including maars near the coast and radially oriented fissure vents, are present on the flanks. Frequent eruptions have been recorded since 1085 CE at vents ranging from the summit to below sea level, causing much damage on this small populated island. After a three-century-long hiatus ending in 1469 CE, activity has been dominated by flank fissure eruptions sometimes accompanied by minor summit eruptions. A 1.6-km-wide summit crater was slowly formed by subsidence during an eruption in 2000. Source: Japan Meteorological Agency (JMA) http://www.jma.go.jp/jma/ Ongoing Activity Aira | Japan | 31.5772°N, 130.6589°E | Summit elev. 1117 m The Japan Meteorological Agency (JMA) reported ongoing eruptive activity at Minamidake Crater (Aira Calderaâ??s Sakurajima volcano) during 16-23 June. One small eruptive event was recorded on 20 June. Weather clouds obscured views during 21-23 June. The Alert Level remained at 3 (on a 5-level scale), and the public was warned to be cautious within 2 km of both the Minimadake and Showa 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/ Awu | Indonesia | 3.689°N, 125.447°E | Summit elev. 1318 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) issued a special report for Awu, noting increased seismicity over a two-day period. On 18 June the seismic network recorded 55 shallow volcanic earthquakes and during 0000-1800 on 19 June the network recorded 81 shallow volcanic earthquakes, three deep volcanic earthquakes, and one low-frequency earthquake. The Alert Level remained at 2 (on a scale of 1-4) and PVMBG reminded the public to stay 3 km away from the craterâ??s center. Geologic Summary. The massive Gunung Awu stratovolcano occupies the northern end of Great Sangihe Island, the largest of the Sangihe arc. Deep valleys that form passageways for lahars dissect the flanks of the volcano, which was constructed within a 4.5-km-wide caldera. Powerful explosive eruptions in 1711, 1812, 1856, 1892, and 1966 produced devastating pyroclastic flows and lahars that caused more than 8000 cumulative fatalities. Awu contained a summit crater lake that was 1 km wide and 172 m deep in 1922, but was largely ejected during the 1966 eruption. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ Dukono | Indonesia | 1.6992°N, 127.8783°E | Summit elev. 1273 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Dukono continued during 18-24 June. Daily white-and-gray or white, gray, and black gas-and-ash plumes rose 500-2,700 m above the summit and drifted SE, E, and NW. Faint rumbling was heard at the observation post, 11 km N, during 6-7 June. Residents 10-11 km away heard occasional booming and rumbling sounds during 18 and 22-24 June. The Alert Level remained at Level 2 (on a scale of 1-4) and the public was warned to stay 4 km away from the Malupang Warirang Crater. Geologic Summary. The Dukono complex in northern Halmahera is on an edifice with a broad, low profile containing multiple peaks and overlapping craters. Almost 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 Gunung Mamuya cone, 10 km NE. Malupang Wariang, 1 km SW of the summit crater complex, contains a 700 x 570 m crater that has also had reported eruptions. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ Etna | Italy | 37.748°N, 14.999°E | Summit elev. 3357 m The Sezione di Catania - Osservatorio Etneo (INGV) reported explosive activity and lava flow at Etna during 16-22 June, though poor weather conditions obscured views all week. Explosive activity at SE Crater was first observed in webcam images at 0123 on 19 June and was described as weak and discontinuous. The intensity strengthened over time, though weather conditions often prevented visual observations. At around 0555 lava overflowed the crater and descended the flanks, traveling NE and curving E. Intense Strombolian activity was visible during 1200-1300 and an eruption plume rose 6-7 km a.s.l. and drifted N. Ashfall was reported in Randazzo (15 km NNE) and in the municipality of Gioiosa Marea (46 km N). The lava flow advanced to 1,930 m elevation and was 3.9 km long. Intermittent incandescent flashes at NE Crater were visible in webcam images on 21 June. Geologic Summary. Mount Etna, towering above Catania on the island of Sicily, has one of the world's longest documented records of volcanism, dating back to 1500 BCE. Historical lava flows of basaltic composition cover much of the surface of this massive volcano, whose edifice is the highest and most voluminous in Italy. The Mongibello stratovolcano, truncated by several small calderas, was constructed during the late Pleistocene and Holocene over an older shield volcano. The most prominent morphological feature of Etna is the Valle del Bove, a 5 x 10 km caldera open to the east. Two styles of eruptive activity typically occur, sometimes simultaneously. Persistent explosive eruptions, sometimes with minor lava emissions, take place from one or more summit craters. Flank vents, typically with higher effusion rates, are less frequently active and originate from fissures that open progressively downward from near the summit (usually accompanied by Strombolian eruptions at the upper end). Cinder cones are commonly constructed over the vents of lower-flank lava flows. Lava flows extend to the foot of the volcano on all sides and have reached the sea over a broad area on the SE flank. Source: Sezione di Catania - Osservatorio Etneo (INGV) http://www.ct.ingv.it/ Great Sitkin | United States | 52.076°N, 176.13°W | Summit elev. 1740 m The Alaska Volcano Observatory (AVO) reported that slow lava effusion continued to feed a thick flow in Great Sitkinâ??s summit crater during 18-24 June. Webcam and satellite views showed slight inflation of the dome near the vent area and rockfall deposits on the S and SE sides of the upper part of the dome. Small daily earthquakes were detected by the seismic network, including signals probably caused by small rockfalls from the growing summit lava dome. Minor steaming from the snow-free dome was visible in clear webcam views during 18-19 June. 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/ Home Reef | Tonga | 18.992°S, 174.775°W | Summit elev. -10 m The Tonga Geological Services reported that unrest at Home Reef continued during 7-21 June. Discolored water around the island was visible in both 16 and 21 June clear satellite images. A steam plume was visible in the 16 June image, but no emissions were visible in the 21 June image. No thermal anomalies nor ash emissions were detected in satellite data. The Aviation Color Code remained at Yellow (the second lowest level on a four-level scale, the Maritime Alert Level remained at Orange (the third level on a four-level scale) with advice to stay at least 2 nautical miles (3.7 km) from the island, and the Alert Level for residents of Vavaâ??u and Haâ??apai remained at Green (the first level on a four-level scale). Geologic Summary. Home Reef, a submarine volcano midway between Metis Shoal and Late Island in the central Tonga islands, was first reported active in the mid-19th century, when an ephemeral island formed. An eruption in 1984 produced a 12-km-high eruption plume, large amounts of floating pumice, and an ephemeral 500 x 1,500 m island, with cliffs 30-50 m high that enclosed a water-filled crater. In 2006 an island-forming eruption produced widespread dacitic pumice rafts that drifted as far as Australia. Another island was built during a September-October 2022 eruption. Source: Tonga Geological Services, Government of Tonga https://www.facebook.com/tongageologicalservice Ibu | Indonesia | 1.488°N, 127.63°E | Summit elev. 1325 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that the eruption at Ibu continued during 18-24 June. Gray or white-to-gray ash plumes rose 300-800 m above the summit and drifted in multiple directions on most days; eruptive events were recorded on 18 June, but visual observations were obscured by weather clouds. Nighttime crater incandescence was visible in some webcam images. The Alert Level remained at 3 (the second highest level on a four-level scale) and the public was advised to stay 4 km away from the active crater and 5 km away from the N crater wall opening. Geologic Summary. The truncated summit of Gunung Ibu stratovolcano along the NW coast of Halmahera Island has large nested summit craters. The inner crater, 1 km wide and 400 m deep, has contained several small crater lakes. The 1.2-km-wide outer crater is breached on the N, creating a steep-walled valley. A large cone grew ENE of the summit, and a smaller one to the WSW has fed a lava flow down the W flank. A group of maars is located below the N and W flanks. The first observed and recorded eruption was a small explosion from the summit crater in 1911. Eruptive activity began again in December 1998, producing a lava dome that eventually covered much of the floor of the inner summit crater along with ongoing explosive ash emissions. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ Karymsky | Russia | 54.049°N, 159.443°E | Summit elev. 1513 m The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that moderate activity continued at Karymsky during 13-19 June. A thermal anomaly over the volcano was identified in satellite images during 17-18 June; the volcano was quiet or weather conditions prevented views on the other days of the week. The Aviation Color Code remained at Orange (the third level on a four-color scale). Dates are based on 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 Kilauea | United States | 19.421°N, 155.287°W | Summit elev. 1222 m The Hawaiian Volcano Observatory (HVO) reported that the eruption within Kilaueaâ??s Kaluapele summit caldera, characterized by episodic fountaining and intermittent spatter at two vents along the SW margin of Halemaâ??umaâ??u Crater, continued at variable levels during 18-24 June. Nighttime incandescence at both the N and S vents and intermittent lava spattering at the N vent were visible during 18-19 June. Small, sporadic periods of spattering and intermittent overflows of lava began at the N vent at 2326 on 19 June. The activity intensified until 0140 on 20 June when lava fountains became sustained. By 0155 the fountain was 250 m tall, and lava was advancing on the crater floor; by 0210 the fountain was over 300 m tall. Lava fountaining at the S vent began at around 0200. The activity at the N vent continued to intensify and by 0326 the fountain at the N vent rose well over 305 m. The eruptive plume rose at least 6 km (20,000 ft) above ground level. Sulfur dioxide emissions were not directly measured, though typical values observed for past episodes of lava fountaining averaged 50,000-75,000 tonnes per day. Gas and tephra drifted S based on wind data from the National Weather Service. Lava flows from both vents covered parts of the crater floor. After about eight hours of continuous fountaining, the N vent stopped erupting at 1007, and the S vent stopped at 1025. Strong incandescence from both vents was visible overnight during 22-24 June. Data analysis revealed that the fountain from the N vent rose 380 m, a new height record for the current eruption. The Volcano Alert Level remained at Watch (the third level on a four-level scale) and the Aviation Color Code remained at Orange (the third color on a four-color scale). Geologic Summary. Kilauea overlaps the E flank of the massive Mauna Loa shield volcano in the island of Hawaii. Eruptions are prominent in Polynesian legends; written documentation since 1820 records frequent summit and flank lava flow eruptions interspersed with periods of long-term lava lake activity at Halemaumau crater in the summit caldera until 1924. The 3 x 5 km caldera was formed in several stages about 1,500 years ago and during the 18th century; eruptions have also originated from the lengthy East and Southwest rift zones, which extend to the ocean in both directions. About 90% of the surface of the basaltic shield volcano is formed of lava flows less than about 1,100 years old; 70% of the surface is younger than 600 years. The long-term eruption from the East rift zone between 1983 and 2018 produced lava flows covering more than 100 km2, destroyed hundreds of houses, and added new coastline. Source: US Geological Survey Hawaiian Volcano Observatory (HVO) https://volcanoes.usgs.gov/observatories/hvo/ Klyuchevskoy | Russia | 56.056°N, 160.642°E | Summit elev. 4754 m The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that a bright thermal anomaly at Klyuchevskoy was identified in satellite images during 13-19 June. 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. Klyuchevskoy is the highest and most active volcano on the Kamchatka Peninsula. Since its origin about 6,000 years ago, this symmetrical, basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. It rises above a saddle NE of Kamen volcano and lies SE of the broad Ushkovsky massif. More than 100 flank eruptions have occurred during approximately the past 3,000 years, with most lateral craters and cones occurring along radial fissures between the unconfined NE-to-SE flanks of the conical volcano between 500 and 3,600 m elevation. Eruptions recorded since the late 17th century have resulted in frequent changes to the morphology of the 700-m-wide summit crater. These eruptions over the past 400 years have originated primarily from the summit crater, but have also included numerous major explosive and effusive eruptions from flank craters. Source: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php Lascar | Chile | 23.37°S, 67.73°W | Summit elev. 5592 m The Servicio Nacional de GeologÃa y MinerÃa (SERNAGEOMIN) reported declining seismicity, low sulfur dioxide emissions, and no deformation at Láscar in recent weeks. During 1-15 June sulfur dioxide emissions measured at a station 6 km ESE averaged 1,254 tonnes per day (t/d) with a maximum value of 2,572 t/d on 12 June. No anomalous emissions were detected in satellite data. White gas plumes visible in webcam views rose as high as 400 m above the crater rim and drifted ESE. Incandescence from the crater was visible during 6, 9-10, and 15 June, and periodically at night through the first half of June. Satellite data continued to show three zones of elevated temperatures on the crater floor. The seismic network recorded fewer and less intense signals indicative of volcanic processes. The Alert Level was lowered to Green (the lowest level on a four-color scale). Geologic Summary. Láscar is the most active volcano of the northern Chilean Andes. The andesitic-to-dacitic stratovolcano contains six overlapping summit craters. Prominent lava flows descend its NW flanks. An older, higher stratovolcano 5 km E, Volcán Aguas Calientes, displays a well-developed summit crater and a probable Holocene lava flow near its summit (de Silva and Francis, 1991). Láscar consists of two major edifices; activity began at the eastern volcano and then shifted to the western cone. The largest eruption took place about 26,500 years ago, and following the eruption of the Tumbres scoria flow about 9000 years ago, activity shifted back to the eastern edifice, where three overlapping craters were formed. Frequent small-to-moderate explosive eruptions have been recorded since the mid-19th century, along with periodic larger eruptions that produced ashfall hundreds of kilometers away. The largest historical eruption took place in 1993, producing pyroclastic flows to 8.5 km NW of the summit and ashfall in Buenos Aires. Source: Servicio Nacional de GeologÃa y MinerÃa (SERNAGEOMIN) http://www.sernageomin.cl/ Lewotolok | Indonesia | 8.274°S, 123.508°E | Summit elev. 1431 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that an eruption at Lewotolok was ongoing during 18-24 June. Daily gray, white-to-gray, or gray-to-black ash plumes rose 400-900 m above the summit of the cone and drifted NW, W, and SW. Clear nighttime webcam images showed incandescent material both at the summit cone and being ejected above the cone. Lava flows on the W and SW flanks of the main volcano edifice were also incandescent. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 2 km away from the vent and 2.5 km away on the S, SE, and W flanks. Geologic Summary. The Lewotolok (or Lewotolo) stratovolcano occupies the eastern end of an elongated peninsula extending north into the Flores Sea, connected to Lembata (formerly Lomblen) Island by a narrow isthmus. It is symmetrical when viewed from the north and east. A small cone with a 130-m-wide crater constructed at the SE side of a larger crater forms the volcano's high point. Many lava flows have reached the coastline. Eruptions recorded since 1660 have consisted of explosive activity from the summit crater. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ Marapi | Indonesia | 0.38°S, 100.474°E | Summit elev. 2885 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Marapi (on Sumatra) continued during 18-24 June. At 1532 on 18 June a gray ash plume rose to around 450 m above the summit and drifted NE. Later that day, at 2009, a gray ash plume to rose around 700 m above the summit and drifted E. According to a news report the second event was accompanied by loud banging and rumbling noises, felt vibrations, and incandescence visible at the summit. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 3 km away from the active crater. Geologic Summary. Gunung Marapi, not to be confused with the better-known Merapi volcano on Java, is Sumatra's most active volcano. This massive complex stratovolcano rises 2,000 m above the Bukittinggi Plain in the Padang Highlands. A broad summit contains multiple partially overlapping summit craters constructed within the small 1.4-km-wide Bancah caldera. The summit craters are located along an ENE-WSW line, with volcanism migrating to the west. More than 50 eruptions, typically consisting of small-to-moderate explosive activity, have been recorded since the end of the 18th century; no lava flows outside the summit craters have been reported in historical time. Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/; Antara News https://www.antaranews.com/berita/4909757/gunung-marapi-sumbar-kembali-erupsi-dengan-abu-capai-700-meter Merapi | Indonesia | 7.54°S, 110.446°E | Summit elev. 2910 m The Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG) reported that the eruption at Merapi (on Java) continued during 13-19 June. Seismicity was less intense than the previous week. The SW lava dome produced 26 lava avalanches that traveled as far as 1.9 km SW down the Bebeng drainage, 20 that traveled as far as 2 km SW down the Krasak drainage, and 56 that traveled as far as 1.9 km W down the Sat/Putih drainage. Small morphological changes to the SW lava dome resulted from continuing effusion and minor collapses. The volume of the SW dome increased by 84,500 cubic meters to an estimated 4,133,800 cubic meters, based on webcam images and a 13 June drone survey. The size of the central dome had not changed. 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/ Nevado del Ruiz | Colombia | 4.892°N, 75.324°W | Summit elev. 5279 m The Servicio Geológico Colombianoâ??s (SGC) Observatorio Vulcanológico y Sismológico de Manizales reported that eruptive activity at Nevado del Ruiz continued during 17-23 June, though weather conditions often obscured visual observations. Seismic data indicated that events associated with fluid movement decreased in both number and intensity compared to the previous week. Seismicity associated with rock fracturing decreased in number but increased in intensity compared to the previous week. The earthquakes were mainly located below Arenas Crater and the NE, E, and SE flanks within 5 km at depths of 1-8 km. Low-energy thermal anomalies on the crater floor were identified in satellite data. Daily sulfur dioxide emissions had decreased compared to the previous week. Gas-and-steam plumes rose as high as 900 m above the summit and drifted NW and WNW; ash was not detected in the plumes. The Alert Level remained at Yellow (the second level on a four-level 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://www2.sgc.gov.co/volcanes/index.html Poas | Costa Rica | 10.2°N, 84.233°W | Summit elev. 2697 m The Observatorio Vulcanológico y Sismológico de Costa Rica-Universidad Nacional (OVSICORI-UNA) reported continuing gas-and-steam emissions with occasional minor amounts of ash at Poás during 18-24 June. Significant amounts of gas-and-steam emissions continued to be emitted, particularly from Boca A. On 18 June sulfur dioxide emissions averaged 273 tons per day (t/d), though they were as high as 1,500 t/d towards the second half of the week; overall, though levels remained high, there has beenwas a decreasing trend in sulfur dioxide emissions during over the previous few weeks, though levels remained high. Gas component ratios indicated less of a magmatic input. Incandescence continued to be visible and detected in infrared webcam views at Boca A vent. The hyperacid lake over Boca C continued to rise, notably on 15 June during a period of heavy rain. Minor amounts of ash in the gas-and-steam plume were visible in webcam images during 1725-1900 on 22 June. The plumes rose 500 m above the crater rim and drifted W. The Comisión Nacional de Emergencias (CNE) lowered the Alert Level to Yellow for Parque Nacional Volcán Poás and district of Toro Amarillo in the Canton of Sarchà (including the Desagüe, Agrio, Anonos, and Gorrión river basins) on 18 June due to decreasing activity. Additionally, the districts of Grecia, Zarcero, Naranjo, Poás, Sabanilla, SarapiquÃ, and Rio Cuarto were no longer under â??alert.â?? The Parque Nacional Volcán Poás remained closed. The Alert Level remained at 2 (the second lowest level on a four-level scale) and the Aviation Color Code remained at Yellow (the second lowest color on a four-color scale). Geologic Summary. The broad vegetated edifice of Poás, one of the most active volcanoes of Costa Rica, contains three craters along a N-S line. The frequently visited multi-hued summit crater lakes of the basaltic-to-dacitic volcano are easily accessible by vehicle from the nearby capital city of San José. A N-S-trending fissure cutting the complex stratovolcano extends to the lower N flank, where it has produced the Congo stratovolcano and several lake-filled maars. The southernmost of the two summit crater lakes, Botos, last erupted about 7,500 years ago. The more prominent geothermally heated northern lake, Laguna Caliente, is one of the world's most acidic natural lakes, with a pH of near zero. It has been the site of frequent phreatic and phreatomagmatic eruptions since an eruption was reported in 1828. Eruptions often include geyser-like ejections of crater-lake water. Sources: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA) http://www.ovsicori.una.ac.cr/; Comisión Nacional de Prevención de Riesgos y Atención de Emergencias (CNE) http://www.cne.go.cr/ Raung | Indonesia | 8.119°S, 114.056°E | Summit elev. 3260 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that Raung continued to erupt during 18-25 June. Seismicity during 16-18 June fluctuated but increased overall. A thermal anomaly on the crater floor was identified in a satellite image on 18 June. Ash plumes rose 500-1,100 m above the crater rim and drifted in multiple directions. Ash plumes during 19-20 June rose as high has 2 km above the crater rim and drifted SE, S, SW, and W. Incandescent emanated from the summit crater during 0302-0500 on 20 June; seismicity decreased that same day. Ash plumes rose 1-2 km above the crater rim and drifted S, SW, and W. PVMBG noted that eruptive activity during 5-20 June produced ash plumes that mostly deposited ash around the crater area. An ash plume on each day during 21-23 June rose 300-600 m above the crater rim and drifted N, NW, W, and SW. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 3 km away from the summit crater. Geologic Summary. Raung, one of Java's most active volcanoes, is a massive stratovolcano in easternmost Java that was constructed SW of the rim of Ijen caldera. The unvegetated summit is truncated by a dramatic steep-walled, 2-km-wide caldera that has been the site of frequent historical eruptions. A prehistoric collapse of Gunung Gadung on the W flank produced a large debris avalanche that traveled 79 km, reaching nearly to the Indian Ocean. Raung contains several centers constructed along a NE-SW line, with Gunung Suket and Gunung Gadung stratovolcanoes being located to the NE and W, respectively. Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM) http://vsi.esdm.go.id/ Semeru | Indonesia | 8.108°S, 112.922°E | Summit elev. 3657 m The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that activity continued at Semeru during 18-24 June, often with multiple daily eruptive events recorded by the seismic network. White-and-gray ash plumes rose 400-1,200 m above the summit and drifted SW, N, and W; no plumes were visible on 22 and 24 June due to weather conditions. The Alert Level remained at 2 (the second lowest level on a scale of 1-4). The public was warned to stay at least 3 km away from the summit in all directions, 8 km from the summit to the SE, 500 m from the banks of the Kobokan drainage as far as 13 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/ Sheveluch | Russia | 56.653°N, 161.36°E | Summit elev. 3283 m The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that lava extrusion may have continued at Sheveluchâ??s â??300 years of RASâ?? dome on the SW flank of Old Sheveluch and at the Young Sheveluch dome during 13-19 June. Thermal anomalies over the domes were identified in satellite images on 13, 15, and 18 June. The Far Eastern Branch of the Russian Academy of Sciences (FEB RAS) reported that minor steam, gas, and ash plumes rose as high as 4.3 km (14,100 ft) a.s.l. and drifted mainly E and SE during 13-14 and 18 June. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates are based on 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. Sources: Kamchatkan Volcanic Eruption Response Team (KVERT) http://www.kscnet.ru/ivs/kvert/index_eng.php; Institute of Volcanology and Seismology (IVS) of the Far Eastern Branch of the Russian Academy of Sciences (FEB RAS) http://www.kscnet.ru/ivs/ Suwanosejima | Japan | 29.638°N, 129.714°E | Summit elev. 796 m The Japan Meteorological Agency (JMA) reported that eruptive activity at Suwanosejima's Ontake Crater continued during 16-23 June. Incandescence was observed nightly in webcam images. Eruptive events at 0730 and at 0823 on 19 June and at 0331 on 21 June produced ash plumes that rose 1.3-1.6 km above the crater rim and drifted E, straight up, and NW, respectively. Another explosion at 1041 on 23 June generated an ash plume that rose 2.3 km above the crater rim and drifted NE. The Alert Level remained at 2 (the second level on a five-level scale) and the public was warned to be cautious within 1.5 km of 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/ 8-8-8-8-8-8-8-8-8-8-8-8-8 ============================================================== 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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