The Weekly Volcanic Activity Report: March 12-18, 2026

New activity/unrest

Akan, Japan

43.384°N, 144.013°E; summit elev. 1499 m

The Japan Meteorological Agency (JMA) reported continuing eruptive activity at Akan (also known as Meakan-dake, which means Meakan Peak) of the Akan volcanic complex during 9-15 March. During a field visit on 9 March scientists measured an average of 300 tons per day of sulfur dioxide emissions, the same as the last measurement on 18 February. Weather clouds obscured webcam views for most of the week, starting during the evening of 11 March. At around 0831 on 13 March a small-amplitude, short-duration volcanic tremor was recorded along with a very slight tilt change; eruptive activity could not be visually confirmed. Weather conditions allowed for clearer webcam views around noon on 15 March. Black deposits, likely volcanic ash, were visible on the snow near Ponmachineshiri Crater’s 96-1 vent; an eruptive event occurred sometime during 11-15 March. The Alert Level remained at 2 (the second lowest level on a 5-level scale) and the public was warned to exercise caution within 500 m of Ponmachineshiri Crater.

Geological summary: Akan is a 13 x 24 km caldera located immediately SW of Kussharo caldera in eastern Hokkaido. The elongated, irregular outline of the caldera rim reflects its incremental formation during major explosive eruptions from the early to mid-Pleistocene. There are four post-caldera stratovolcanoes, three at the SW end of the caldera and the other on the NE side. Conical Oakandake was frequently active during the Holocene. The 1-km-wide Nakamachineshiri crater of Meakandake was formed during a major pumice-and-scoria eruption about 13,500 years ago. The Meakandake group, composed of nine overlapping cones E of Lake Akan, has produced mild phreatic eruptions since the beginning of the 19th century. The main cone of Meakandake proper has a triple crater at its summit. Although recorded eruptions at Meakandake have consisted of minor phreatic explosions, four major magmatic eruptions with pyroclastic flows have also occurred during the Holocene.

Ambae, Vanuatu

15.389°S, 167.835°E; summit elev. 1496 m

The eruption at Ambae continued during 12-18 March based on reports from the Vanuatu Meteorology and Geohazards Department (VMGD) and the Wellington Volcanic Ash Advisory Center (VAAC). According to the VAAC daily gas, steam, and ash plumes were visible in webcam and satellite images rising as high as 4 km (13,000 ft) a.s.l., or about 2.5 km above the summit, and drifting W, SW, and E. The plumes had variable densities, were sometimes intermittent, and occasionally obscured by weather clouds. There was a strong sulfur dioxide signal identified in satellite images, notably during 14-15 March. During 15-16 March the plumes may have contained ash. Active lava was visible in webcam images on 16 March. On 19 March VMGD stated that seismicity remained high characterized by tremor and volcano-seismic events. The gas-and-steam emissions continued to contain variable amounts of ash during 6-19 March based on satellite and webcam images, and a thermal anomaly continued to be identified in satellite images. Incandescence at the summit was visible in webcam images on 8, 12, and 16 March.

The Ministry of Health stated that as of 12 March no deaths or injuries as a result of the activity had been reported, though heavy ashfall continued to impact areas mainly to the S and W. The ashfall damaged gardens and contaminated local water sources. Health facilities reported an increase in illnesses associated with ash and gas exposure and water contamination. A total of 52 people voluntarily evacuated to other areas. 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.

Lascar, Chile

52.331°N, 174.139°W; summit elev. 1518 m

On 14 March the Alaska Volcano Observatory (AVO) reported that small earthquakes and weak tremor at the Atka volcanic complex was recorded by the seismic network during the past week. Elevated levels of sulfur dioxide gas were detected in satellite data. Seismicity significantly increased during 1620-1630 on 14 March, prompting AVO to raise the Volcano Alert Level to Advisory (the second lowest level on a four-level scale) and the Aviation Color Code to Yellow (the second lowest color on a four-color scale) about an hour later.

Geological summary: The Atka Volcanic Complex consists of a central shield and Pleistocene caldera and four notable volcanic cones. A major explosive dacitic eruption accompanied formation of the caldera about 500,000 to 300,000 years ago; approximately half of the caldera rime remains, open towards the NW. The Sarichef cone, ~5 km ESE of the caldera rim, retains a symmetrical profile, unlike most other heavily eroded features outside the caldera to the S and W. The Kliuchef stratovolcano grew within the caldera and exhibits five eruptive vents striking NE, including two at the summit, that have been active in the Holocene. A 700-m-diameter crater 1 km NE of the summit may have been the source vent for a large 1812 CE eruption. Hot springs and fumaroles are located on the flanks of Kliuchef and in a glacial valley to the SW. The most frequently active volcano of the complex is Korovin, at the NE tip of Atka Island about 5 km N of Kliuchef. An 800-m-diameter crater on the SE side of the summit contains a deep circular pit that sometimes contains a crater lake thought to be the source of phreatic ash explosions. The smaller Konia cone, slightly offset to the E, lies between Kliuchef and Korovin. Most of the lava flows in the complex are basaltic, though some dacitic flows are also present.

Lewotobi, Indonesia

8.542°S, 122.775°E; summit elev. 1703 m

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported periodic ash plumes at Lewotobi Laki-laki during 12-18 March. Daily white plumes rose as high as 100 m above the summit and drifted N and NE on most days; emissions were not visible on 14 March. An eruptive event at 0725 on 15 March produced a dense gray ash plume that rose around 800 m above the summit and drifted NE and E. The Alert Level remained at 2 (the second lowest level on a scale of 1-4) and the exclusion zone was a radius of 4 km 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.

Piton de la Fournaise, France

21.244°S, 55.708°E; summit elev. 2632 m

The Observatoire Volcanologique du Piton de la Fournaise (OVPF) reported that the eruption at Piton de la Fournaise continued during 11-18 March. Deformation data showed inflation, then stability, followed by deflation through the week. Tremor levels abruptly dropped at around 0850 on 11 March, along with a decrease in the lava-flow rate, and then remained stable for a few days. Tremor significantly increased on 14 March, and at 1915 on 16 March began to be accompanied by intermittent “gas pistoning” signals. Seismicity resumed beneath the summit with a notable increase recorded early on 18 March.

The crater opening at the active cone on the lower SE flank of Dolomieu Crater continued to be active with minor ejections of lava above the crater rim. Lava mainly flowed downslope though tubes and reemerged at elevations higher than the Grandes Pentes area, causing the flow field to widen, thicken, and expand. The N lava flow had stopped on 16 February, at about 1,725 m elevation approximately 2.6 km from the road. The S lava flow that had begun descending the E flank on 3 March, S of the main branch, continued to advance and produced numerous breakouts. The S flow advanced at variable rates, influenced by the topography and vegetation encountered along its path; flow rates were estimated to be 2-70 meters per hour during 11-13 March, and occasionally stalled. At around 0802 on 13 March the lava flows crossed the National Road 2 (RN2). The Alert Level was raised to 2.2 (on a 0–4 scale). Flows crossed the road at two more locations that day, at 0837 and at 1235, and by the morning of 14 March a section of road over 260 m wide was covered with lava. The most distal area of the flow was about 310 m from the coastline by 0500 on 14 March, and 150 m away by 0200 on 15 March. Several breakouts occurred upslope of the road, though flows from them advanced slowly. Lava reached the ocean at around 1220 on 16 March. OVPF scientists measured lava temperatures of 1,100-1,130 degrees Celsius as it reached the ocean. Acidic plumes composed of sea water, steam, and volcanic gases rose at the points where lava contacted ocean water. Thermal surveys revealed that the water within an area 600 m in diameter exceeded 36 degrees Celsius. Accumulated lava and lava fragments at the ocean entry began building a platform that had extended the coastline about 85 m by 18 March.

Geological summary: Piton de la Fournaise is a massive basaltic shield volcano on the French island of Réunion in the western Indian Ocean. Much of its more than 530,000-year history overlapped with eruptions of the deeply dissected Piton des Neiges shield volcano to the NW. Three scarps formed at about 250,000, 65,000, and less than 5,000 years ago by progressive eastward slumping, leaving caldera-sized embayments open to the E and SE. Numerous pyroclastic cones are present on the floor of the scarps and their outer flanks. Most recorded eruptions have originated from the summit and flanks of Dolomieu, a 400-m-high lava shield that has grown within the youngest scarp, which is about 9 km wide and about 13 km from the western wall to the ocean on the E side. More than 150 eruptions, most of which have produced fluid basaltic lava flows, have occurred since the 17th century. Only six eruptions, in 1708, 1774, 1776, 1800, 1977, and 1986, have originated from fissures outside the scarps.

Whakaari/White Island, New Zealand

37.52°S, 177.18°E; summit elev. 294 m

The GeoNet reported that a minor eruption at Whakaari/White Island may have started as early as 8 March, based on new satellite data, and ended on 11 March. Minor ash emissions were primarily reported by pilots and identified in photos, and ashfall on the crater floor was visible in the photos. The eruption did not alter the vent nor eject rocks. According to the Wellington Volcanic Ash Advisory Center (VAAC) low-level gas-and-steam emissions containing ash were identified in satellite images on 11 March rising 610 m (2,000 ft) a.s.l. and drifting W and SW. GeoNet noted that no eruptive activity was identified during 12-17 March in satellite images or in the Whakatane and Te Kaha webcams located along the Bay of Plenty coast. During a 16 March overflight scientists observed thin ash deposits on the inner crater floor around the active vent and on the S part of the island, but no ash was present in the gas-and-steam emissions rising from the crater. Volcanic gas levels were elevated but not as high compared to those measured during previous eruptive activity last year. At 1500 on 17 March the Volcanic Alert Level was lowered to 2 (on a scale of 0-5) and the Aviation Color Code was lowered to Yellow (the second lowest level on a four-color scale).

Geological summary: The uninhabited Whakaari/White Island is the 2 x 2.4 km emergent summit of a 16 x 18 km submarine volcano in the Bay of Plenty about 50 km offshore of North Island. The island consists of two overlapping andesitic-to-dacitic stratovolcanoes. The SE side of the crater is open at sea level, with the recent activity centered about 1 km from the shore close to the rear crater wall. Volckner Rocks, sea stacks that are remnants of a lava dome, lie 5 km NW. Descriptions of volcanism since 1826 have included intermittent moderate phreatic, phreatomagmatic, and Strombolian eruptions; activity there also forms a prominent part of Maori legends. The formation of many new vents during the 19th and 20th centuries caused rapid changes in crater floor topography. Collapse of the crater wall in 1914 produced a debris avalanche that buried buildings and workers at a sulfur-mining project. Explosive activity in December 2019 took place while tourists were present, resulting in many fatalities. The official government name Whakaari/White Island is a combination of the full Maori name of Te Puia o Whakaari (“The Dramatic Volcano”) and White Island (referencing the constant steam plume) given by Captain James Cook in 1769.

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 Caldera’s Sakurajima volcano) during 9-16 March. Very small eruptive events were recorded and crater incandescence was visible in webcam images at night. 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.

Bulusan, Philippines

12.769°N, 124.056°E; summit elev. 1535 m

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported increased seismicity at Bulusan in a 17 March advisory, with a total of 90 volcanic earthquakes recorded by the seismic network during 0000-1200. The seismicity mostly consisted of weak volcano-tectonic earthquakes associated with rock fracturing located at depths of 5 km or less beneath the edifice. All other monitoring parameters were at baseline levels. Weak-to-moderate gas emissions rose from the summit crater and active vents; sulfur dioxide emissions were below background levels on 12 March averaging 40 tonnes per day. No significant ground deformation or changes in monitored thermal springs were detected. The Alert Level remained at 0 (the lowest level on a scale of 0-5).

Geological summary: Luzon’s southernmost volcano, Bulusan, was constructed along the rim of the 11-km-diameter dacitic-to-rhyolitic Irosin caldera, which was formed about 36,000 years ago. It lies at the SE end of the Bicol volcanic arc occupying the peninsula of the same name that forms the elongated SE tip of Luzon. A broad, flat moat is located below the topographically prominent SW rim of Irosin caldera; the NE rim is buried by the andesitic complex. Bulusan is flanked by several other large intracaldera lava domes and cones, including the prominent Mount Jormajan lava dome on the SW flank and Sharp Peak to the NE. The summit is unvegetated and contains a 300-m-wide, 50-m-deep crater. Three small craters are located on the SE flank. Many moderate explosive eruptions have been recorded since the mid-19th century.

Fuego, Guatemala

14.4748°N, 90.8806°W; summit elev. 3799 m

The Instituto Nacional de Sismología, Vulcanologia, Meteorologia e Hidrología (INSIVUMEH) reported that eruptive activity at Fuego continued during 11-18 March. Daily Strombolian explosions recorded by the seismic network, at rates of 6-13 per hour when reported, generated gas-and-ash plumes that rose as high as 1.2 km above the summit and drifted as far as 30 km in multiple directions. Rumbling sounds that were sometimes loud, shock waves, and/or sounds associated with gas emissions were reported daily or almost daily, and were audible in villages and municipalities around the volcano. Explosions occasionally ejected incandescent material as high as 300 m above the summit and sometimes produced incandescent avalanches on the flanks. Daily incandescent block avalanches descending the Ceniza (SSW), Las Lajas (SE), Santa Teresa (W), Taniluyá (SSW), Seca (W), Honda, and Trinidad (SSW) drainages sometimes reached vegetated areas. Ashfall was reported in areas downwind including Panimaché I and II (8 km SW), Morelia (10 km SW), El Porvenir (11 km SW), Santa Sofia (12 km SW), La Rochela (8 km SW), Ceilán (9 km S), El Rodeo (10 km SSE), El Zapote (10 km SSE), and surrounding areas during 11-15 March, and in San Cayetano (7 km E), La Reunión (7 km SE), El Rodeo, and El Zapote during 17-18 March.

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; summit elev. 1740 m

The Alaska Volcano Observatory (AVO) reported that slow lava effusion continued to feed a thick flow in Great Sitkin’s summit crater during 12-18 March, particularly to the SW. Very low seismic activity was characterized by occasional small volcanic earthquakes and daily small rockfalls within the crater. Minor steaming, rockfalls, and elevated surface temperatures were observed in satellite views on multiple days. 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.

Home Reef, Tonga

18.992°S, 174.775°W; summit elev. -10 m

The Tonga Geological Services reported continuing activity at Home Reef during 6-14 March. Lava flows were active on the S and E flanks. A new cinder cone at the vent was detected in radar satellite data on 6 March and may have formed sometime during 28 February-6 March. A 13 March Sentinel satellite image showed a plume of discolored water drifting S. A diffuse gray gas-and-steam plume rose from the vent. Low-level thermal anomalies were identified in other sources, including MIROVA and Himawari satellite data. The Aviation Color Code remained at Orange (the second highest level on a four-level scale, the Maritime Alert Level remained at Red (the highest 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 Vava’u and Ha’apai remained at Green (the first level on a four-level scale).

Geological 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.

Ibu, Indonesia

1.4941°N, 127.6324°E; summit elev. 1357 m

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that activity at Ibu continued during 12-18 March, with daily eruptive events recorded by the seismic network. White-and-gray ash plumes rose 300-700 m above the summit and drifted N, NE, E, and SE on most days; emissions were not visible during 12-14 March due to weather conditions. Incandescence at the summit was visible in a few 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; summit elev. 2422 m

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported continuing eruptive activity at Kanlaon during 11-18 March. The seismic network recorded 2-9 daily volcanic earthquakes, and on 15 March two periods of volcanic tremor lasting three and 229 minutes long. Daily sulfur dioxide emissions ranged from 434 to 2,021 tonnes per day. Emissions were visible daily, generally rising 150-600 m above the summit and drifting in various directions.

A one-minute moderately explosive eruption at 1807 on 15 March generated a grayish ash plume that rose 5 km above the summit and drifted E then S. Large incandescent blocks were ejected as far as 1 km from the crater rim and hot ejecta ignited two fires along the forest margins on the upper SE flank that burned until approximately 0330 the next morning. The monitoring station closest to the crater was damaged after being engulfed in fire. Pyroclastic density currents (PDCs) descended the upper S flank as far as 1 km. A shockwave produced a booming or rumbling sound, heard up to 18 km away, that registered as a maximum of 181 pascals by an infrasound station about 5 km E. Various amounts of ashfall were reported in 55 barangays (neighborhoods) in 12 cities/municipalities across the central Negros Island Region. The heaviest ashfall occurred in the municipality of La Castellana, with barangays reporting trace amounts to 1 mm of ashfall. One barangay reported a sulfur odor and two reported ground vibrations. Ashfall was also reported in barangays in the cities/municipalities of Moises Padilla, Binalbagan, Isabela, Himamaylan, Kabankalan City, Pontevedra, Ilog, and Hinigaran, Sulfur odors were reported in the municipalities San Carlos and Don Salvador Benedicto, and shockwaves were reported by residents of Canlaon City. The explosion was followed by three hours and 49 minutes of weak volcanic tremor and diffuse and continuous ash emissions that were often obscured. 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; summit elev. 1222 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 11-18 March. Incandescence at both the N and S vents was visible on most nights, though it was stronger and more frequent at the S vent; rainy weather conditions sometimes prevented views, notably during 14-15 March. Both vents emitted steam-and-gas plumes, and during the last part of the week abundant steam rose from the hot flows within Halema’uma’u Crater.

HVO determined that the lava fountains on 10 March were the tallest recorded during this current eruption, with the S vent fountain rising as high as 540 m and the N vent fountain rising as high as 430 m. 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: 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.

Lewotolok, Indonesia

8.274°S, 123.508°E; summit elev. 1431 m

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported ongoing eruptive activity at Lewotolok during 12-18 March. White plumes rose as high as 50 m above the summit and drifted NW, NE, and E during 12, 15-16, and 18 March; emissions were not visible on the other days. Crater incandescence was visible in a webcam image on 13 March. A webcam image from 2112 on 16 March showed incandescent material being ejected above the summit and onto the flanks. 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; summit elev. 2885 m

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that eruptive activity at Marapi (on Sumatra) continued during 12-18 March. White plumes rose as high as 800 m above the summit and drifted SE, SW, and W during 15-18 March. Emissions were not visible on the other days. An eruptive event was recorded at 2329 on 14 March but not visually observed. According to the Darwin Volcanic Ash Advisory Centre (VAAC) an ash plume was identified in satellite images rising to 6.7 km (22,000 ft) a.s.l. (or about 3.8 km above the summit) and drifting NE at 0510 on 15 March. A Volcano Observatory Notice for Aviation (VONA) issued on 16 March noted that a white-and-gray plume rose as high as 1.5 km above the summit and drifted in multiple directions. 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; summit elev. 2462 m

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported that the eruption at Mayon continued during 12-18 March, characterized by lava effusion and collapses at the summit dome, pyroclastic density currents (PDCs), incandescent rockfalls, ash plumes, active lava flows, and occasional minor Strombolian activity. Emissions rose as high as 800 m above the summit and drifted in various directions on most days; views were obscured during 13-14 March. The seismic network recorded 290-444 daily rockfalls and 3-8 daily PDCs. The number of daily earthquakes increased towards the end of the week with 126-287 daily volcanic earthquakes during 11-14 and 18 March, 539 volcanic earthquakes on 15 March, and 425 volcanic earthquakes on 16 March. Daily measurements of sulfur dioxide emissions averaged 1,220-2,928 tonnes per day. The lava flows did not advance in the Mi-isi (S) and Basud (E) drainages, remaining 1.3 and 3.8 km long, respectively. The lava flow in the Bonga (SE) drainage advanced 100 m during 14-15 March to reach a total length of 3.2 km. Short periods of lava fountaining were recorded during 12, 15-16, and 18 March, notably during 0332-0710 and 1133-1134 on 16 March.

By 1800 on 17 March a total of 4,020 people (1,105 families) were staying in 12 evacuation shelters, and an additional 86 people (27 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; summit elev. 2910 m

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that the eruption at Merapi (on Java) continued during 12-18 March with daily lava avalanches and occasional pyroclastic flows. White plumes rose as high as 500 m above the summit and drifted in multiple directions almost daily; emissions were not visible on 12 March. There were 5-23 lava avalanches that traveled as far as 2 km down the Sat/Putih drainage (W flanks) almost daily; on 16 March five lava avalanches descended the Bebeng drainage (SW flank) as far as 2 km. The seismic network detected one pyroclastic flow on 14 March, two on 15 March, and two on 16 March. 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.

Popocatepetl, Mexico

19.023°N, 98.622°W; summit elev. 5393 m

The Centro Nacional de Prevención de Desastres (CENAPRED) reported that eruptive activity continued at Popocatépetl during 11-18 March. The seismic network recorded 6-36 long-period events per day, accompanied by steam-and-gas emissions that drifted in multiple directions; the emissions contained ash during 11-12 March. In addition, the seismic network recorded 0-65 minutes of tremor daily. Periods of seismically detected emissions lasted three hours and 31 minutes during 11-12 March and 43 minutes during 12-13 March. According to the Washington Volcanic Ash Advisory Center (VAAC) a thermal anomaly in the crater was identified in satellite images on 11 March. A plume with possible ash on 11 March and ash plumes during 12-13 March were visible in webcam and satellite images rising 6.1-6.7 km (20,000-22,000 ft) a.s.l. (as high as 1.3 km above the summit) and drifting NW and NE. The Alert Level remained at Yellow, Phase Two (the middle level on a three-color scale) and the public was warned to stay 12 km away from the crater.

Geological 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.

Purace, Colombia

2.3095°N, 76.3948°W; summit elev. 4650 m

The Servicio Geologico Colombiano (SGC) reported ongoing low-level eruptive activity at Puracé during 10-16 March. Seismicity indicating fluid movement included long-period earthquakes, tremor pulses, and continuous tremor. The seismicity was located beneath Puracé Crater at depths of less than 1 km, and was related to internal movement of gases as well as emissions. On 15 March two of the signals were associated with ash emissions (at around 1300 and at 1716) that rose as high as 600 m above the summit and drifted E. Seismic activity associated with rock fracturing processes was mainly located beneath Piocollo and Puracé volcanoes at depths of 1-3 km; the level of seismicity was similar to the previous week. Sulfur dioxide emissions from fissures in Curiquinga and Piocollo volcanoes and a thermal anomaly continued to be detected in satellite images. 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.

Sabancaya, Peru

15.787°S, 71.857°W; summit elev. 5960 m

The Instituto Geofísico del Perú’s (IGP) Centro Vulcanológico Nacional (CENVUL) reported continuing eruptive activity at Sabancaya during 11-18 March. The seismic network detected 8-16 daily earthquakes indicating the movement of magma and gases. As many as four daily thermal anomalies were identified in satellite images. Gas, steam, and ash plumes rose as high as 1.8 km above the summit and drifted SW, W, and NW during 11-12 March. Daily gas-and-steam emissions during the rest of the week rose 100-800 m above the summit and drifted in multiple directions. An explosion at 1357 on 18 March generated an ash plume that rose 2 km above the summit and drifted S, SW, and NW. 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.

Santa Maria, Guatemala

14.757°N, 91.552°W; summit elev. 3745 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 11-18 March, with continuing lava extrusion at Caliente dome. Incandescence at the summit was sometimes observed during dark hours. Daily explosions, 0-3 per hour when reported, generated gas-and-ash plumes that rose 700-800 m above the dome and drifted as far as 20 km in multiple directions. Effusion of blocky lava and collapses of material produced daily incandescent block avalanches that descended the flanks, mainly to the SW, E, and NE. The block avalanches were sometimes accompanied by short pyroclastic flows; curtains of ash were generated by pyroclastic flows during 11-12 March. Minor ashfall was reported in areas downwind including Las Marías (10 km S), Viejo Palmar (11 km S), San Marcos Palajunoj (10 km SW), and Loma Linda (7 km W) during 11-12 March, in Las Marías, Viejo Palmar, and San Marcos Palajunoj during 14-15 March, and in Santa María de Jesús (5 km SE), Calaguaché (9 km S), Belén (10 km S), Las Marías, and Pueblo Nuevo during 17-18 March.

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; summit elev. 3657 m

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that activity continued at Semeru during 12-18 March, with daily eruptive events recorded by the seismic network. Daily white-to-gray ash plumes were visible rising 300-1,500 m above the summit and drifting N and W. 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; summit elev. 3283 m

The Kamchatkan Volcanic Eruption Response Team (KVERT) reported continuing eruptive activity at the active lava domes along the N crater floor of Young Sheveluch (on the SW flank of Old Sheveluch) during 11-18 March. A daily thermal anomaly was identified in satellite images. Explosions during 11-12 March generated ash plumes that rose as high as 8 km (19,700 ft) a.s.l. and drifted 2,410 km E and NE. Ash plumes from explosions on 16 March rose up to 11 km (36,100 ft) a.s.l. and drifted more than 1,800 km E. 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.

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; summit elev. 796 m

The Japan Meteorological Agency (JMA) reported that eruptive activity at Suwanosejima’s Ontake Crater continued during 6-13 March. Incandescence was observed nightly in webcam images. An eruptive event on 10 March produced a plume that rose 900 m above the crater rim. Rumbling was heard at the Suwanosejima Branch Office in Toshima village (3.5 km SSW). 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.

Katmai, United States

58.279°N, 154.9533°W; summit elev. 2047 m

The Alaska Volcano Observatory (AVO) reported that on 15 March strong winds in the vicinity of Katmai and the Valley of Ten Thousand Smokes dispersed unconsolidated ash up to 1.8 km (6,000 ft) a.s.l. to the SE. The ash was originally deposited during the Novarupta-Katmai eruption in 1912. The Volcano Alert Level remained at Normal (the lowest level on a four-level scale) and the Aviation Color Code remained at Green (the lowest level on a four-color scale).

Geological summary: Katmai was initially considered to be the source of the Valley of Ten Thousand Smokes ash flow in 1912. However, the 3 x 4 km caldera of 1912 is now known to have formed as a result of the voluminous eruption at nearby Novarupta volcano. The edifice had four NE-SW-trending summits, most of which were truncated by the 1912 collapse. Two or more large explosive eruptions took place during the late Pleistocene. Most of the two overlapping pre-1912 Katmai volcanoes are Pleistocene, but Holocene lava flows from a flank vent descend the SE flank of the SW edifice into the Katmai River canyon. The steep walled young caldera has a jagged rim that rises 500-1,000 m above the caldera floor and contains a deep lake. Lake waters have covered a small post-collapse lava dome (Horseshoe Island) that was seen on the caldera floor at the time of the initial ascent to the caldera rim in 1916.

References:

¹ Smithsonian Institution / US Geological Survey Weekly Volcanic Activity Report – GVP – March 12-18, 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.

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