The Weekly Volcanic Activity Report: June 4-10, 2026

New activity/unrest: Ambae, Vanuatu | Nevado de Longavi, Chile | Titan Ridge, Papua New Guinea.

New activity/unrest

Ambae, Vanuatu

15.389°S, 167.835°E; Elev. 1,496 m

The Wellington Volcanic Ash Advisory Center (VAAC) reported that emissions of ash-and-gas plumes from Ambae were identified during 4-5 June using satellite and webcam images. The plumes rose 3 km (10,000 ft) a.s.l. and drifted S. The Alert Level remained at 3 (on a scale of 0-5), and the public was warned to stay outside of Danger Zone B, defined as a 3-km radius around the active vents in Lake Voui, and to stay away from drainages during heavy rains.

Geological summary: The island of Ambae, also known as Aoba, is a massive 2,500 km3 basaltic shield that is the most voluminous volcano of the New Hebrides archipelago. A pronounced NE-SW-trending rift zone with numerous scoria cones gives the 16 x 38 km island an elongated form. A broad pyroclastic cone containing three crater lakes (Manaro Ngoru, Voui, and Manaro Lakua) is located at the summit within the youngest of at least two nested calderas, the largest of which is 6 km in diameter. That large central edifice is also called Manaro Voui or Lombenben volcano. Post-caldera explosive eruptions formed the summit craters about 360 years ago. A tuff cone was constructed within Lake Voui (or Vui) about 60 years later. The latest known flank eruption, about 300 years ago, destroyed the population of the Nduindui area near the western coast.

Nevado de Longavi, Chile

36.1959°S, 71.1641°W; Elev. 3,175 m

The Servicio Nacional de Geología y Minería (SERNAGEOMIN), Servicio Nacional de Prevención y Respuesta ante Desastres (SENAPRED), and the Servicio Geológico Minero Argentino (SEGEMAR) stated that seismicity at Nevado de Longaví gradually declined after a seismic swarm on 20 May. A few isolated seismic events were recorded during 21-31 May, with activity close to baseline levels. The Alert Level remained at Yellow (the second lowest level on a four-color scale) and SENAPRED maintained a “Preventative Early Warning” for the communities of Longaví (53 km WNW), Linares (55 km NW), and Colbún (60 km NNW).

Geological summary: The conical Nevado de Longaví is a late-Pleistocene to Holocene, dominantly andesitic stratovolcano constructed over a basement of Tertiary volcaniclastic and granitic rocks. Two edifice-collapse events modified the E and SW flanks of a pre-Holocene edifice, and Holocene activity has been concentrated at the summit and on the E flanks. Andesitic-to-dacitic lava domes occupy the summit region. The latest eruptions produced a lava dome in the upper part of the collapse scarp and summit region that partially collapsed to the E, forming block-and-ash flow deposits. Fumarolic activity has been reported.

Titan Ridge, Papua New Guinea

3.03°S, 147.78°E; Elev. -1,300 m

The Rabaul Volcano Observatory (RVO) reported that the eruption at Titan Ridge continued during 4-9 June. The number of hydroacoustic signals per day decreased during 4-8 June, followed by a minor increase on 9 June. A narrow but dense steam plume drifted about 50 km NW at low altitudes due to strong winds. A possible small intermittent plume may have risen from an area just to the SW of the main plume. Despite a reduction in the number of daily acoustic events, thermal anomalies around the plume area had intensified. Significant amounts of floating pumice, forming thick and extensive rafts, continued to wash up on the shores of the Admiralty Islands. According to a news article pumice rafts impacted the S coastline of Manus Island and made boat access difficult or impossible. An observer reported that one of the pumice rafts was about 3 km wide, 5 km long, and around 5 m deep. The rafts covered reefs and grasses, and caused the deaths of fish.

Geological summary: SOFAR signals resembling those produced at known submarine eruptions were recorded in January 1972 in the central Bismarck Sea (Johnson et al., 1981). The source of the signals was at the junction of two segments of the N margin of the South Bismarck plate. The more easterly of these segments is a transform fault, whereas the more westerly is an area of oblique active seafloor spreading. The signals were detected by a seismic station on nearby Manus Island, as well as at hydrophone stations on Wake and Midway Islands in the central Pacific. During the eruption in 2026 the “Titan Ridge” name was proposed by local residents. The general story of the Titan (pronounced Tee-Tahn) people is that their island home got devastated and reduced to the Circular Reef (~40 km SSW) due to an uncertain natural phenomenon; they drifted for awhile before they settled, and most of the Titan villages are now mainly along the south coast of Manus Island.

Ongoing activity

Aira, Japan

31.5772°N, 130.6589°E; Elev. 1,117 m

The Japan Meteorological Agency (JMA) reported ongoing eruptive activity at Minamidake Crater (Aira Caldera’s Sakurajima volcano) during 1-8 June. Sulfur dioxide emissions were high, averaging 2,900 tons per day on 3 June. Very small eruptive events were detected during 1-5 June. Continuous ash emissions during 0652-0755 on 7 June rose as high as 1.3 km above the crater rim and drifted SE and W. A news article stated that ash fell across Kagoshima City, though this was unconfirmed by JMA. An explosion later that day, at 1907, was recorded by the seismic network but not visually observed. An explosion at 2141 on 8 June generated an ash plume that rose 700 m above the crater rim and drifted SE and ejected large blocks 500-700 m from the crater. 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.

Geological 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.

Dukono, Indonesia

1.6992°N, 127.8783°E; Elev. 1,273 m

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Dukono continued during 4-10 June. Daily white-to-gray or gray-to-black plumes rose 300-2,000 m above the summit and drifted N, NE, E, and NW. Faint rumbling was heard at the Dukono observation post (11 km N) on 6 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.

Geological 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.

Fuego, Guatemala

14.4748°N, 90.8806°W; Elev. 3,799 m

The Instituto Nacional de Sismología, Vulcanologia, Meteorologia e Hidrología (INSIVUMEH) reported that eruptive activity at Fuego continued during 3-10 June. Daily Strombolian explosions recorded by the seismic network, at rates of 4-12 per hour when reported, generated gas-and-ash plumes that rose as high as 1.1 km above the summit and drifted as far as 40 km NW, W, and SW. Rumbling sounds, shock waves, and/or sounds associated with gas emissions were reported almost every day. Explosions ejected incandescent material as high as 300 m above the summit and onto the flanks, causing incandescent block avalanches to descend the W, SW, and S flanks; notably the avalanches descended the Seca (W), Taniluyá (SSW), Ceniza (SSW), Las Lajas (SE), and Honda drainages, sometimes reaching vegetated areas. Ashfall was reported in communities on the W flanks or around the crater area on a few of the days. Rainfall during the evenings of 4 to 5 June triggered lahars on both days that descended the Ceniza drainage and were composed of a mixture of water, fine volcanic material, tree branches and trunks, and blocks measuring from 30 cm to 3 m in diameter. During the evening of 6 June lahars of similar composition descended the El Jute and Las Lajas drainages.

Geological 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 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.

Great Sitkin, United States

52.076°N, 176.13°W; Elev. 1,740 m

The Alaska Volcano Observatory (AVO) reported that slow lava effusion continued to feed a thick flow in Great Sitkin’s summit crater during 3-10 June. A satellite image acquired on 6 June confirmed that slow growth was concentrated along the E margin. Daily minor seismicity was detected by the seismic network. Weather clouds sometimes prevented webcam and satellite observations, though slightly elevated surface temperatures were visible in satellite images during 5-10 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).

Geological 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.

Ibu, Indonesia

1.4941°N, 127.6324°E; Elev. 1,357 m

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that activity at Ibu continued during 4-10 June, with daily eruptive events recorded by the seismic network. Daily gray or white-to-gray ash plumes rose 300-800 m above the summit and drifted in multiple directions. Incandescence at the summit was visible in some nighttime webcam images. The Alert Level remained at 2 (the second lowest level on a four-level scale) and the public was advised to stay 2 km away from the active crater and 3.5 km away from the N crater wall opening.

Geological 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.

Kanlaon, Philippines

10.4096°N, 123.13°E; Elev. 2,422 m

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported continuing eruptive activity at Kanlaon during 4-10 June. The seismic network recorded 5-15 daily volcanic earthquakes; during 4-8 June the seismic counts included 1-4 daily periods of volcanic tremor lasting 3 minutes to two hours and 39 minutes each. Sulfur dioxide emissions ranged from 990 to 2,682 tonnes per day. Daily volcanic emissions rose as high as 1.5 km above the summit and drifted SE, S, and W. There were 1-4 daily periods of ash emissions during 4-8 June lasting as short as five minutes to as long as two hours and 39 minutes. Specifically, the webcam recorded grayish ash emissions at 0553 on 6 June rising 800 m above the crater rim and drifting SW. The Alert Level remained at 2 (on a scale of 0-5); the public was warned to stay out of the 4-km-radius Permanent Danger Zone (PDZ) and pilots were advised to avoid flying close to the summit.

Geological summary: Kanlaon volcano (also spelled Canlaon) forms the highest point on the Philippine island of Negros. The massive andesitic stratovolcano is covered with fissure-controlled pyroclastic cones and craters, many of which are filled by lakes. The largest debris avalanche known in the Philippines traveled 33 km SW from Kanlaon. The summit contains a 2-km-wide, elongated northern caldera with a crater lake and a smaller but higher active vent, Lugud crater, to the south. Eruptions recorded since 1866 have typically consisted of phreatic explosions of small-to-moderate size that produce minor local ashfall.

Kilauea, United States

19.421°N, 155.287°W; Elev. 1,222 m

The Hawaiian Volcano Observatory (HVO) reported that the eruption within Kilauea’s Kaluapele summit caldera, characterized by episodic fountaining, incandescence, and intermittent spatter from craters along the SW margin of Halema’uma’u Crater, continued at variable levels during 3-10 June. Robust gas plumes rose from both the N and S vents though the week. Bright and continuous incandescence persisted at the S vent and flames likely caused by the ignition of volcanic gases escaping the vent were periodically observed. Incandescence at the N vent was intermittent. A small lava flow oozed out of the main cooling flow overnight during 3-4 June. The Volcano Alert Level remained at Advisory and the Aviation Color Code remained at Yellow.

Geological 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.

Lewotobi, Indonesia

8.542°S, 122.775°E; Elev. 1,703 m

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that activity continued at Lewotobi Laki-Laki during 2-10 June. Two dense gray ash plumes rose 600 m and 1,000 m above the summit and drifted in multiple directions on 2 June. A few dense gray ash plumes were visible on 4 June rising 800-1,200 m above the summit and drifted SW, W, and NW. Multiple daily dense gray ash plumes rose as high as 2.5 km above the summit and drifted SW, W, and NW during 5-10 June. Incandescence at the summit and incandescent material being ejected above the summit and onto the flanks were visible in webcam images at 1828 and 2250 on 5 June. Summit incandescence was visible in webcam images on 6 June (at 0049, 0117, and 0213), and 10 June (at 2230 and 2355). The Alert Level remained at 3 (on a scale of 1-4), and the public was warned to stay 5 km away from the center of Laki-Laki.

Geological 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.

Lewotolok, Indonesia

8.274°S, 123.508°E; Elev. 1,431 m

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported ongoing eruptive activity at Lewotolok during 4-10 June. Daily white plumes rose as high as 500 m above the summit and drifted in multiple directions. Incandescent material was ejected above the summit on 6 June, and summit incandescence was visible in a webcam image at 2150 on 8 June and at 2343 on 10 June. Rumbling was heard at the observation post (6 km SW) on 10 June. The Alert Level remained at 2 (on a scale of 1-4) and the public was warned to stay 2 km away from the summit.

Geological 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.

Marapi, Indonesia

0.38°S, 100.474°E; Elev. 2,885 m

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Marapi (on Sumatra) continued during 4-10 June. A diffuse gray plume rose 500 m above the crater rim on 6 June and gray plumes rose 400 m above the summit on 10 June. White plumes rose 100-500 m above the crater rim during 7-8 June. An eruptive event at 2219 on 9 June generated a gray ash plume that rose 500 m above the crater rim and drifted NE. 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.

Geological 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.

Mayon, Philippines

13.257°N, 123.685°E; Elev. 2,462 m

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported that the eruption at Mayon continued during 4-10 June, characterized by lava effusion, periodic pyroclastic density currents (PDCs), incandescent rockfalls, ash-and-gas plumes, and occasional minor Strombolian activity. Emissions were visible daily rising as high as 1.3 km above the summit and drifting in various directions. Each day the seismic network recorded 185-391 rockfalls, 0-3 PDCs, and 12-39 volcanic earthquakes. The earthquake counts included 3-22 daily periods of volcanic tremor, each lasting between 1-41 minutes. Daily measurements of sulfur dioxide emissions averaged 1,088-3,096 tonnes per day. The lava flows did not advance in the Mi-isi (S), Basud (E), and Bonga (SE) drainages, remaining 1.8, 3.8, and 3.2 km long, respectively.

The number of evacuees was similar to the previous week; by 1800 on 8 June a total of 3,973 people (1,088 families) were staying in 12 evacuation shelters, and an additional 137 people (40 families) were staying with friends or relatives, according to the Disaster Response Operations Monitoring and Information Center (DROMIC). The Alert Level remained at 3 (on a 0-5 scale) and residents were reminded to stay away from the 6-km-radius Permanent Danger Zone (PDZ). PHIVOLCS recommended that civil aviation authorities advise pilots to avoid flying close to the summit.

Geological summary: Symmetrical Mayon, which rises above the Albay Gulf NW of Legazpi City, is the most active volcano of the Philippines. The steep upper slopes are capped by a small summit crater. Recorded eruptions since 1616 CE range from Strombolian to basaltic Plinian, with cyclical activity beginning with basaltic eruptions, followed by longer periods of andesitic lava flows. Eruptions occur predominately from the central conduit and have also produced lava flows that travel far down the flanks. Pyroclastic density currents and mudflows have commonly swept down many of the approximately 40 ravines that radiate from the summit and have often damaged populated lowland areas. A violent eruption in 1814 killed more than 1,200 people and devastated several towns.

Merapi, Indonesia

7.54°S, 110.446°E; Elev. 2,910 m

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that the eruption at Merapi (on Java) continued during 4-10 June with occasional lava avalanches produced by the active lava dome on the upper SW flank. White plumes rose as high as 150 m above the summit on most days. There were 1-6 daily lava avalanches that traveled as far as 2 km down the Sat/Putih drainage (W flank). The seismic network also detected one daily pyroclastic flow each day during 5 and 8-9 June. A pyroclastic flow traveled 2 km down the Sat/Putih drainage on 10 June. 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.

Geological 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.

Purace, Colombia

2.3095°N, 76.3948°W; Elev. 4,650 m

The Servicio Geologico Colombiano (SGC) reported ongoing low-level eruptive activity at Puracé during 2-8 June. Seismic activity associated with rock fracturing processes and hybrid events were mainly located beneath Piocollo and Puracé volcanoes at depths of 1-4 km; the level of seismicity slightly increased compared to the previous week. A thermal anomaly continued to be detected in satellite images within the crater of Puracé and in the fumarolic field along its outer rim. Sulfur dioxide emissions rates persisted at high levels. The rate of deformation between Puracé, Piocollo, and Curiquinga volcanoes slowed. Signals associated with fluid movement and emissions, primarily periods of continuous tremor or tremor pulses, increased in both frequency and intensity. The signals located beneath both Puracé and Piocollo at depths less than 3 km. Gas-and-ash emissions rose as high as 2 km above the summit and drifted NW and W. Ashfall was reported in the rural communities of Hato Viejo (12 km WNW), Ambiró, Patico, Pululó, Chapío (9 km NW), Cristales, Campamento, 20 de Julio, Anambío, Loma Linda, the municipal seat of Coconuco (Puracé municipality), and from certain sectors of the city of Popayán. The Alert Level remained at Yellow (the second lowest level on a four-color scale).

Geological summary: Puracé is an active andesitic volcano with a 600-m-diameter summit crater at the NW end of the Los Coconucos Volcanic Chain. This volcanic complex includes nine composite and five monogenetic volcanoes, extending from the Puracé crater more than 6 km SE to the summit of Pan de Azúcar stratovolcano. The dacitic massif which the complex is built on extends about 13 km NW-SE and 10 km NE-SW. Frequent small to moderate explosive eruptions reported since 1816 CE have modified the morphology of the summit crater, with the largest eruptions in 1849, 1869, and 1885.

Reventador, Ecuador

0.077°S, 77.656°W; Elev. 3,562 m

The Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN) reported that eruptive activity at Reventador continued at a high level during 3-10 June. Seismicity included 56-103 daily explosions, long-period earthquakes, harmonic tremor, and tremor associated with emissions. Ash-and-gas plumes, sometimes multiple per day, were visible in webcam and satellite images and reported by the Washington Volcanic Ash Advisory Center (VAAC). The ash plumes rose 400-1,300 m above the crater rim and drifted mainly NW, W, and SW. Incandescent blocks were also visible during dark hours rolling as far as 1,050 m down the flanks. Thermal anomalies were often identified in satellite images. Secretaría de Gestión de Riesgos (SGR) maintained the Alert Level at Orange (the second highest level on a four-color scale).

Geological summary: Volcán El Reventador is the most frequently active of a chain of Ecuadorian volcanoes in the Cordillera Real, well east of the principal volcanic axis. The forested, dominantly andesitic stratovolcano has 4-km-wide avalanche scarp open to the E formed by edifice collapse. A young, unvegetated, cone rises from the amphitheater floor to a height comparable to the rim. It has been the source of numerous lava flows as well as explosive eruptions visible from Quito, about 90 km ESE. Frequent lahars in this region of heavy rainfall have left extensive deposits on the scarp slope. The largest recorded eruption took place in 2002, producing a 17-km-high eruption column, pyroclastic flows that traveled up to 8 km, and lava flows from summit and flank vents.

Sabancaya, Peru

15.787°S, 71.857°W; Elev. 5,960 m

The Instituto Geofísico del Perú’s (IGP) Centro Vulcanológico Nacional (CENVUL) reported continuing eruptive activity at Sabancaya during 1-7 June. The seismic network detected 51 seismic events related to the movement of magmatic fluids and additional earthquakes indicating rock fracturing. Gas, steam, and ash plumes periodically rose as high as 2.5 km above the crater rim and drifted less than 10 km E and SE. Thermal anomalies on the crater floor were identified in satellite images and moderate sulfur dioxide emissions averaged 565 tons per day. An explosion was detected at 1154 on 1 June. The Alert Level remained at Orange (the third level on a four-color scale) and the public was warned to stay outside of a 12 km radius from the summit.

Geological summary: Sabancaya, located in the saddle NE of Ampato and SE of Hualca Hualca volcanoes, is the youngest of these volcanic centers and the only one to have erupted in historical time. The oldest of the three, Nevado Hualca Hualca, is of probable late-Pliocene to early Pleistocene age. The name Sabancaya (meaning “tongue of fire” in the Quechua language) first appeared in records in 1595 CE, suggesting activity prior to that date. Holocene activity has consisted of Plinian eruptions followed by emission of voluminous andesitic and dacitic lava flows, which form an extensive apron around the volcano on all sides but the south. Records of observed eruptions date back to 1750 CE.

Sangay, Ecuador

2.005°S, 78.341°W; Elev. 5,286 m

The Instituto Geofísico-Escuela Politécnica Nacional (IG-EPN) reported that the eruption continued at Sangay during 3-10 June. The seismic network recorded 41-317 daily explosions. Ash-and-gas plumes were visible in webcam views, satellite images, and/or reported by the Washington Volcanic Ash Advisory Center on most days rising 500-1,100 m above the crater rim and drifting W and NW. Weather conditions often obscured views. The Secretaría de Gestión de Riesgos (SGR) maintained the Alert Level at Yellow (the second highest level on a four-color scale).

Geological summary: The isolated Sangay volcano, located east of the Andean crest, is the southernmost of Ecuador’s volcanoes and its most active. The steep-sided, glacier-covered, dominantly andesitic volcano grew within the open calderas of two previous edifices which were destroyed by collapse to the east, producing large debris avalanches that reached the Amazonian lowlands. The modern edifice dates back to at least 14,000 years ago. It towers above the tropical jungle on the east side; on the other sides flat plains of ash have been eroded by heavy rains into steep-walled canyons up to 600 m deep. The earliest report of an eruption was in 1628. Almost continuous eruptions were reported from 1728 until 1916, and again from 1934 to the present. The almost constant activity has caused frequent changes to the morphology of the summit crater complex.

Santa Maria, Guatemala

14.757°N, 91.552°W; Elev. 3,745 m

The Instituto Nacional de Sismología, Vulcanología, Meteorología e Hidrología (INSIVUMEH) reported high levels of ongoing eruptive activity at Santa Maria’s Santiaguito dome complex during 3-10 June, with continuing lava extrusion at Caliente dome. Incandescence at the summit was observed during dark hours. Daily explosions, 0-4 per hour when reported, generated gas-and-ash plumes that rose 700-900 m above the dome and drifted as far as 20 km S, SW, and W. Effusion of blocky lava and collapses of material produced daily incandescent block avalanches that descended the flanks, mainly to the W, SW, and S; on a few of the days these collapses occurred at a rate of 2-5 per hour. Minor ashfall was reported in Finca Monte Bello (6 km WSW), Loma Linda (7 km W), and surrounding areas during 3-4 June. Heavy rain caused lahars to descend the Nimá I drainage on the S flank and the El Tambor drainage on the SSW flank on 3 June and the El Tambor drainage on 5 June. The lahars were composed of water, fine sediments, tree trunks and branches, and blocks up to 1 m in diameter. A collapse on the SW flank was accompanied by a pyroclastic flow that reached the base of the cone and caused the suspension of ash in the air around the SW, S, and SE flanks during 9-10 June. Ashfall was reported in San Marcos Palajunoj (8 km SW), Loma Linda (7 km W), and surrounding communities.

Geological summary: Symmetrical, forest-covered Santa María 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.

Semeru, Indonesia

8.108°S, 112.922°E; Elev. 3,657 m

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that activity continued at Semeru during 4-10 June, with daily eruptive events recorded by the seismic network. Daily white-to-gray ash plumes rose 300-1,200 m above the summit and drifted in multiple directions. The Alert Level remained at 3 (the second lowest level on a scale of 1-4) and the public was warned to stay at least 5 km away from the summit in all directions, 13 km from the summit on the SE flank along the Kobokan drainage, and 500 m from the banks of the Kobokan drainage as far as 17 km SE of the summit.

Geological 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.

Sheveluch, Russia

56.653°N, 161.36°E; Elev. 3,283 m

The Kamchatkan Volcanic Eruption Response Team (KVERT) reported continuing eruptive activity at the lava domes along the N crater floor of Young Sheveluch (on the SW flank of Old Sheveluch) during 4-10 June. A daily thermal anomaly was identified in satellite images. Ash plumes from an explosive event at 1135 on 4 June rose 8 km (26,200 ft) a.s.l. and drifted 370 km NW and N. The ash cloud had drifted 440 km NE by the next day. Explosive and extrusive activity escalated on 6 June at 0755; an ash plume had risen to 12 km (39,400 ft) a.s.l. by 0800 and was drifting 10 km E based on satellite data. At 0817 KVERT raised the Aviation Color Code (ACC) to Red (the highest level on a four-color scale). Ash plumes continued be generated and by 0905 ash plumes were rising to10 km (32,800 ft) a.s.l. and drifting 50 km NE. An ash cloud identified in satellite images at 2110 was 346 x 32 km in size and had drifted 68 km downwind. The ACC was lowered to Orange at 2241 on 6 June because explosive activity had ceased. Another strong explosive event starting at 0439 on 8 June produced ash plumes that rose 10 km a.s.l. and drifted NW. The ACC was raised to Red at 0452. Explosions ceased and an ash cloud, 250 x 230 km in dimension, drifted 300 km NE. The ACC was lowered to Orange at 2221. Dates are based on UTC; specific events are in local time where noted.

Geological 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.

Suwanosejima, Japan

29.638°N, 129.714°E; Elev. 796 m

The Japan Meteorological Agency (JMA) reported that eruptive activity at Suwanosejima’s Ontake Crater continued during 29 May-5 June. Eruptive events generated plumes that rose as high as 900 m above the crater rim. No explosions were recorded. 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.

Geological 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.

Taal, Philippines

14.0106°N, 120.9975°E; Elev. 311 m

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported eruptive activity at Taal during 3-10 June. The seismic network recorded 1-11 daily periods of volcanic tremor lasting one minute to three hours and 14 minutes, and as many as 11 volcanic earthquakes during 6-9 June. Daily gas-and-steam emissions rose as high as 1.5 km above the crater rim and drifted NE. Daily minor phreatomagmatic events, lasting 1-4 minutes, were recorded during 3-6 June. A phreatomagmatic event during 1624-1628 on 5 June generated a jetting plume to a height of 300 m as seen in images from webcams on the N and W rims. Another event the next day, during 1455-1456 on 6 June, produced a plume that rose 100 m above the lake. The Alert Level remained at 1 (on a scale of 0-5); PHIVOLCS reminded the public that the entire Taal Volcano Island (TVI) was a Permanent Danger Zone (PDZ) and recommended that the Main Crater and areas along the Daang Kastila fissure should remain prohibited. Pilots were warned to avoid flying over TVI.

Geological 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.

References:

¹ Smithsonian Institution / US Geological Survey Weekly Volcanic Activity Report – GVP – June 4-10, 2026 – Managing Editor: Sally Sennert

Teo Blašković

I'm a dedicated researcher, journalist, and editor at The Watchers. With over 20 years of experience in the media industry, I specialize in hard science news, focusing on extreme weather, seismic and volcanic activity, space weather, and astronomy, including near-Earth objects and planetary defense strategies. You can reach me at teo /at/ watchers.news.

Earth

Space

Space weather

Monitoring tools

watchers.LIVE

SWX

SAM

StormWall

Support, updates, and contact

Subscribe

Newsletter

Report an event

Feeds and contact