The Weekly Volcanic Activity Report: January 1-7, 2026

New activity/unrest

Ambae, Vanuatu

15.389°S, 167.835°E | Summit elev. 1496 m

The Wellington Volcanic Ash Advisory Center (VAAC) reported that low-level ash plumes at Ambae rose 1.5 km (5,000 ft) a.s.l. and drifted N during 4-5 January. According to the Vanuatu Meteorology and Geohazards Department (VMGD) the Alert Level remained at 2 (on a scale of 0-5), and the public was warned to stay outside of Danger Zone A, defined as a 2-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.

Ambrym, Vanuatu

16.25°S, 168.12°E | Summit elev. 1334 m

The Vanuatu Meteorology and Geohazards Department (VMGD) reported that at 0650 on 8 January an ash plume at Ambrym was identified in satellite images. Seismic data confirmed ongoing unrest that was characterized by volcanic tremor and several volcano-seismic events. The Alert Level remained at 2 (on a scale of 0-5). VMGD warned the public to stay outside of Permanent Danger Zone A, defined as a 1-km radius around Benbow Crater and a 2-km radius around Marum Crater, and to stay 500 m away from the ground cracks created by the December 2018 eruption.

Geological summary: Ambrym is a large basaltic volcano with a 12-km-wide caldera formed during a major Plinian eruption with dacitic pyroclastic flows about 1,900 years ago. A thick, almost exclusively pyroclastic sequence, initially dacitic then basaltic, overlies lava flows of a pre-caldera shield volcano. Post-caldera eruptions, primarily from Marum and Benbow cones, have partially filled the caldera floor and produced lava flows that ponded on the floor or overflowed through gaps in the caldera rim. Post-caldera eruptions have also formed a series of scoria cones and maars along a fissure system oriented ENE-WSW. Eruptions have been frequently reported since 1774, though mostly limited to extra-caldera eruptions that would have affected local populations. Since 1950 observations of eruptive activity from cones within the caldera or from flank vents have occurred almost yearly.

Bur ni Telong, Indonesia

4.769°N, 96.821°E | Summit elev. 2617 m

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported increased seismicity at Bur ni Telong on 30 December. A M 4.5 earthquake was detected at 2043 on 30 December and located about 5 km SW of the summit. The earthquake was followed by an increase in the number of deep volcanic earthquakes (VA) and shallow volcanic earthquakes (VB) beneath the volcano; by 2130 the seismic network had recorded 12 VAs, seven VBs, and one local tectonic earthquake. Four earthquakes were felt. Six more earthquakes located about 5 km SW were detected by 2245. Seismicity began to increase in July 2025, with events progressively getting stronger and closer to the surface, especially during November-December. At 2245 the Alert level was raised to 3 (the second highest level on a scale of 1-4) and the public was warned to stay 4 km away from the crater area and to avoid the fumarole and solfatara regions, especially during cloudy or rainy weather. According to news reports about 2,000 residents evacuated, mainly from Rembune (3 km WSW) and Pantan Pediangan (3 km W). A total of 16 earthquakes were recorded during 30-31 December, though seismicity decreased through the day on 31 December. On 3 January PVMBG lowered the Alert Level to 2 and the public was warned to stay 3 km away from the crater.

Geological summary: The conical Bur ni Telong volcano was constructed at the southern base of the massive Bur ni Geureudong volcanic complex, one of the largest in northern Sumatra. The historically active volcano lies 4.5 km from the summit of Geureudong,and its summit crater has migrated to the ESE, leaving arcuate crater rims. Lava flows are exposed on the southern flank. Explosive eruptions were recorded during the 19th and 20th centuries.

Etna, Italy

37.748°N, 14.999°E | Summit elev. 3357 m

The Sezione di Catania – Osservatorio Etneo (INGV) reported that eruptive activity at Etna’s summit craters continued during 29 December 2025-4 January 2026, characterized by explosive activity (mainly at Voragine Crater) and advancing lava flows in the Valle del Bove. Visual observations were often hindered by weather conditions. On 29 December explosive activity at the BN-2 vent at Bocca Nuova Crater and from the vent on the E flank of the Voragine Crater produced ash emissions that rapidly dispersed near the summit. The NE Crater (Northeast Crater) produced sporadic ash emissions and flashes of incandescence visible at night. Beginning on 30 December summit activity was concentrated at Voragine Crater with Strombolian activity and minor ash emissions. Beginning at around 1730 on 1 January, as the weather conditions cleared, lava flows were visible within the Valle del Bove in webcam images. Satellite images and field observations conducted by INGV scientists revealed that at least two vents had opened just upslope of Mount Simone at about 2,050-2,100 m elevation. Intense spattering activity had built hornitos around the vents. By 1900 the lava flow field consisted of several branches, with the longest branch reaching an area just S of Rocca Musarra, around 1,570 m elevation. On 2 January the most advanced lava flow had reached 1,420 m elevation and was about 2.8 km long. During the next day, on 3 January, INGV scientists observed the flow field and launched drones. They noted that the longest branch had advanced 330 m since the previous day, reaching 1,380 m elevation, and had a total length of 3.14 km. The most active part of the flow field was between 1,800 m and 1,700 m elevation; this area consisted of several active branches, some newer flows overlapped older flows. The flow field area was an estimated 550,000 square meters. Lava flows were active on 4 January, though the longest flow was stationary and cooling.

Geological 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.

Kikai, Japan

30.793°N, 130.305°E | Summit elev. 704 m

The Japan Meteorological Agency (JMA) reported that after the 29 December 2025 eruption at Iodake Crater (at Satsuma Iwo-jima, a subaerial part of Kikai’s NW caldera rim), no additional eruptive activity was detected through 2 January 2026. Nighttime incandescence at the summit was detected in webcam images. Seismicity remained low. The Alert Level remained at 2 (on a 5-level scale), and residents were warned to be cautious within 500 m away from Iodake Crater.

Geological summary: Multiple eruption centers have exhibited recent activity at Kikai, a mostly submerged, 19-km-wide caldera near the northern end of the Ryukyu Islands south of Kyushu. It was the source of one of the world’s largest Holocene eruptions about 6,300 years ago when rhyolitic pyroclastic flows traveled across the sea for a total distance of 100 km to southern Kyushu, and ashfall reached the northern Japanese island of Hokkaido. The eruption devastated southern and central Kyushu, which remained uninhabited for several centuries. Post-caldera eruptions formed Iodake (or Iwo-dake) lava dome and Inamuradake scoria cone, as well as submarine lava domes. Recorded eruptions have occurred at or near Satsuma-Iojima (also known as Tokara-Iojima), a small 3 x 6 km island forming part of the NW caldera rim. Showa-Iojima lava dome (also known as Iojima-Shinto), a small island 2 km E of Satsuma-Iojima, was formed during submarine eruptions in 1934 and 1935. Mild-to-moderate explosive eruptions have occurred during the past few decades from Iodake, a rhyolitic lava dome at the eastern end of Satsuma-Iojima.

Masaya, Nicaragua

11.9844°N, 86.1688°W | Summit elev. 594 m

The Washington Volcanic Ash Advisory Center (VAAC) reported that at 0750 on 2 January a diffuse ash plume from Masaya was visible in satellite and webcam images rising to 1.2 km (4,000 ft) a.s.l. and drifting less than 20 km SW.

Geological summary: Masaya volcano in Nicaragua has erupted frequently since the time of the Spanish Conquistadors, when an active lava lake prompted attempts to extract the volcano’s molten “gold” until it was found to be basalt rock upon cooling. It lies within the massive Pleistocene Las Sierras caldera and is itself a broad, 6 x 11 km basaltic caldera with steep-sided walls up to 300 m high. The caldera is filled on its NW end by more than a dozen vents that erupted along a circular, 4-km-diameter fracture system. The Nindirí and Masaya cones, the source of observed eruptions, were constructed at the southern end of the fracture system and contain multiple summit craters, including the currently active Santiago crater. A major basaltic Plinian tephra erupted from Masaya about 6,500 years ago. Recent lava flows cover much of the caldera floor and there is a lake at the far eastern end. A lava flow from the 1670 eruption overtopped the north caldera rim. Periods of long-term vigorous gas emission at roughly quarter-century intervals have caused health hazards and crop damage.

Mayon, Philippines

13.257°N, 123.685°E | Summit elev. 2462 m

The Philippine Institute of Volcanology and Seismology (PHIVOLCS) reported that escalating numbers of rockfalls preceded the extrusion of new lava at Mayon. Beginning in November 2025 rockfalls from the summit lava dome became more frequent based on visual and seismic observations. A total of 599 rockfalls were recorded during November-December, averaging 21 events per day. Photos of the summit dome on 8 and 10 December revealed that dark lava spines had been recently extruded. On 31 December a total of 47 rockfalls were recorded, the highest number recorded in a single day in 2025. Ground deformation had been anomalous for the previous 18 months, notably at the E and NE flanks; inflation at the W and SW flanks began to be detected in May 2025. At 0600 on 1 January 2026 the Alert Level was raised to 2 (on a 0-5 scale); the public was warned to stay out of the 6-km-radius Permanent Danger Zone (PDZ) and pilots were advised to avoid flying close to the summit.

Sulfur dioxide emissions remained at background levels, averaging 288 tonnes per day (t/d) on 2 January and 702 t/d on 5 January. The seismic network continued to detect a high number of rockfalls from the unstable summit dome; a total of 346 rockfalls were recorded during 1-6 January as well as four volcanic earthquakes. The rockfalls lasted 1-5 minutes and descended the S flank less than 1 km. The volume of the rockfalls increased on 5 January and incandescence at the summit was seen at night, indicting the extrusion of new lava at the summit. Beginning at 1226 on 6 January a collapse of new material from the summit generated a three-minute-long pyroclastic density current (PDC) that traveled less than 2 km down the Bonga drainage on the SE flank. At 1320 the Alert Level was raised to 3. The Albay Provincial Information Office reported that the governor ordered the evacuation of residents living within the PDZ. Activity continued to increase through the day; in total there were 131 rockfalls and five PDCs detected on 6 January . By 0600 on 7 January a total of 3,476 people (952 families) had moved to 13 evacuation shelters, and an additional 39 people (12 families) were staying with friends or relatives, according to a report from the Disaster Response Operations Monitoring and Information Center (DROMIC). Collapses at the summit dome continued on 7 January; a total of 16 discrete PDC events were recorded during 1226-1630, generating grayish to brownish ash clouds that rose 200 m and drifted ENE. According to the Tokyo VAAC ash plumes during 1458-1928 on 7 January rose 2.4-3 km (8,000-10,000 ft) a.s.l., or as high as 580 m above the summit, and drifted NW and ENE.

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.

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 a magmatic intrusion occurred beneath Dolomieu Crater at Piton de la Fournaise on 1 January based on seismic and deformation data. Seismicity began to increase at 0447 and by 0600 the seismic network had recorded 304 volcanic-tectonic earthquakes at depths of 1.6-2.3 km. The majority of earthquakes were less than M 1. The increased seismicity was accompanied by rapid, minor deformation (up to 10 microradians) at the summit area that lasted less than an hour. The data suggested that an intrusion occurred during 0445-0550 beneath the SW edge of Dolomieu Crater at a depth of around 1 km. The Alert Level was raised to 1 (or an Orange Alert) and access to the volcano was restricted at 0600. Seismicity decreased following the intrusion and returned to a pre-intrusion rate of about 1-3 earthquakes per hour.

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.

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 29 December 2025-7 January 2026. The seismic network detected 6-25 daily earthquakes indicating the movement of magma and gases. There were 0-4 daily thermal anomalies at the bottom of the crater identified in satellite images. Ash, steam, and gas plumes generally rose as high as 1 km above the crater rim during 29-30 December, though at 1646 on 30 December a plume rose 1.4 km above the crater rim. During 31 December-6 January gas-and-steam plumes rose 200-600 m above the crater rim. Ash, steam, and gas plumes rose 500 m above the crater rim during 6-7 January. The emissions drifted within 10 km in various directions throughout the week. 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.

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 29 December 2025-6 January 2026. Nightly crater incandescence was visible in webcam images and small eruptive events were occasionally detected. A period of continuous emissions during 1558-1710 on 6 January produced ash plumes that rose as high as 1 km above the crater rim and drifted S. 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.

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 31 December 2025-7 January 2026. Seismicity was quiet and weather clouds often obscured satellite and webcam views. Weakly elevated surface temperatures were observed in satellite images during 30 December-3 January. 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 | Summit elev. 1357 m

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported that the eruption at Ibu continued during 31 December 2025-7 January 2026. Eruptive events were recorded daily. White-to-gray or gray ash plumes rose 400-800 m above the summit and drifted in multiple directions during 31 December-2 January and on 4 January; weather conditions prevented visual confirmation on the other days. 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 30 December 2025-7 January 2026. The seismic network recorded 1-4 daily volcanic earthquakes. Gas-and-steam emissions of variable densities rose as high as 950 m above the crater rim and drifted in various directions. Daily sulfur dioxide emissions ranged from 550 to 2,598 tonnes per day. Two periods of ash emissions were visible on 3 January, one lasted 21 minutes and the other lasted one hour and four minutes. One of the emissions was captured in webcam images at 1635; it was grayish, rose 300 m above the crater rim, and drifted SW. Based on webcam images a grayish plume rose 350 m above the crater rim and drifted SW at 0555 on 6 January; the ash emission lasted for three hours and 30 minutes. Two periods of ash emissions were visible on 7 January, one lasted one hour and 48 minutes and the other lasted for six hours and 21 minutes. One of the emissions was captured in webcam images at 1458; it was grayish, rose 900 m above the crater rim, and drifted NW. 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.

Katmai, United States

58.279°N, 154.9533°W | Summit elev. 2047 m

The Alaska Volcano Observatory (AVO) reported that on 30 December 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.

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 30 December 2025-7 January 2026. Webcam views showed persistent incandescence from the S vent and several instances of brief incandescence from the N vent during most nights. Incandescence at the N vent intensified during 3-4 January and then was intermittent at both vents during 5-6 January. Spattering at the N vent was occasionally visible during 6-7 January. 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.

Krasheninnikov, Russia

54.596°N, 160.27°E | Summit elev. 1816 m

The Kamchatkan Volcanic Eruption Response Team (KVERT) reported that eruptive activity at Krasheninnikov continued during 25 December 2025-1 January 2026. A large daily thermal anomaly over the volcano was identified in satellite images. Satellite images showed active lava flows on the ENE flank on 1 January. The Aviation Color Code remained at Orange (the second highest level on a four-color scale). Dates and times are provided in Coordinated Universal Time (UTC); specific events are indicated in local time where specified.

Geological summary: The late Pleistocene to Holocene Krasheninnikov volcano is comprised of two overlapping stratovolcanoes within a 9 x 10 km Pleistocene caldera. Young lava flows from summit and flank vents descend both into the caldera and down its outer flanks, and older flows that covered much of the SE caldera rim extended downslope at least 7 km. Tephra deposits from the caldera-forming eruption directly overlie a 39,000 years before present (BP) tephra thought to be associated with the formation of Uzon caldera (Florenskii, 1988). The intra-caldera stratovolcanoes are situated along a NE-SW-trending fissure that has also produced zones of Holocene cinder cones extending 15-20 km beyond the caldera. Construction of the southern edifice began about 11,000 years BP and lasted for about 4,500 years; it has a summit crater about 800-900 m wide. The northern edifice was constructed during a cycle of similar length that began about 6,500 years ago; it has a summit crater about 1.5 km wide, within which is low cone with an 800-m-wide crater containing another small cone. An eruptive cycle during about 600-400 years BP (1350-1550 CE) produced the Pauk lava cone in the crater of the northern cone and the Yuzhny lava flow on SW flank outside the caldera, followed by the Molodoy flow from the upper SW flank (Ponomareva, 1987; Ponomareva and Tsyurupa, 1985; Ponomareva and Braitseva, 1990).

Lewotolok, Indonesia

8.274°S, 123.508°E | Summit elev. 1431 m

The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) reported increased eruptive activity at Lewotolok. Increased seismicity was detected during 1-4 January. Generally white plumes rose 25-50 m above the summit, though at 1209 on 4 January a white-and-gray ash plume rose about 300 m above the summit and material was ejected 300 m and onto the SE flank. White-and-gray ash plumes rose 200-500 m above the summit and drifted E and NE at 1543 on 5 January, at 0831 on 6 January, and at 0831, at 1152, and at 1802 on 7 January. 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 and 2.5 km away on the SSE and W flanks.

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 31 December 2025-7 January 2026. An eruptive event at 0458 on 6 January produced a dense white-to-gray ash plume that rose to around 250 m above the summit and drifted SE. An eruptive event was recorded at 1323 on 7 January, though weather conditions prevented visual confirmation. 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.

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 30 December 2025-8 January 2026. The seismic network recorded 13-60 long-period events per day, accompanied by steam-and-gas emissions with occasional minor ash content that drifted in various directions. In addition, the seismic network recorded 0-110 minutes of tremor daily and 0-2 daily volcano-tectonic earthquakes. According to the Washington Volcanic Ash Advisory Center (VAAC) ash plumes visible in webcam and satellite images during 31 December and 1, 3-4, and 7 January rose 5.8-6.7 km (19,000-22,000 ft) a.s.l. (as high as 1.3 km above the summit) and drifted in multiple directions. 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 continuing eruptive activity at Puracé during 30 December 2025-7 January 2026. Seismicity was characterized by pulses of tremor, long-period signals indicating fluid movement, and periods of continuous tremor. The seismicity was located at depths of less than 1.5 km and was related to internal movement of gases as well as emissions. Daily gas-and-ash emissions, 2-11 per day, were associated with some seismic signals and visible in webcam images rising 200 to over 800 m above the summit and drifting downwind, mainly NE, NW, and W; weather conditions sometimes obscured views. Significant sulfur dioxide emissions were detected in satellite data. Elevated temperatures in the crater area continued to be detected and were possibly associated with the emissions of hot gases. White gas-and-steam emissions, first observed on 18 November, continued to rise from the fissure on the inner N wall. Ashfall was reported in Coconuco (12 km WNW) and Popayán (28 km NW) during 31 December-1 January. Ashfall and gas odors were reported in the Cristales area (27 km NW) during 3-4 January. Low-magnitude seismic activity associated with rock fracturing processes was located beneath Piocollo volcano at depths of 1-2 km during 5-7 January. On 6 January high amounts of rainfall on areas of ash deposits produced a secondary lahar down the Cocuy River drainage on the NE flank of the Puracé, Piocollo, and Curiquinga volcano chain. The Alert Level remained at Orange (the second highest level on a four-color scale) and the public was warned to stay away from the crater.

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.

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 31 December 2025-7 January 2026, with daily eruptive events recorded by the seismic network. White-and-gray or gray ash plumes were observed daily rising 400-1,000 m above the summit and drifting in multiple directions. Minor incandescence at the summit on the upper SE flank was visible in some nighttime webcam images. 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 Sheveluch’s “300 years of RAS” dome on the SW flank of Old Sheveluch and at the Young Sheveluch dome during 25 December 2025-1 January 2026. A thermal anomaly was identified in satellite images during 25 and 29-31 December; weather clouds obscured views on the other days. 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 26 December 2025-2 January 2026. Incandescence was observed nightly in webcam images. An eruptive event at 2254 on 6 January generated an ash plume that rose 1.2 km above the crater rim and drifted SE. 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.

Telica, Nicaragua

12.606°N, 86.84°W | Summit elev. 1036 m

The Washington Volcanic Ash Advisory Center (VAAC) reported that at 0720 on 2 January a diffuse ash plume at Telica was visible in satellite and webcam images rising to 1.5 km (5,000 ft) a.s.l. and drifting less than 10 km SW.

Geological summary: Telica, one of Nicaragua’s most active volcanoes, has erupted frequently since the beginning of the Spanish era. This volcano group consists of several interlocking cones and vents with a general NW alignment. Sixteenth-century eruptions were reported at symmetrical Santa Clara volcano at the SW end of the group. However, its eroded and breached crater has been covered by forests throughout historical time, and these eruptions may have originated from Telica, whose upper slopes in contrast are unvegetated. The steep-sided cone of Telica is truncated by a 700-m-wide double crater; the southern crater, the source of recent eruptions, is 120 m deep. El Liston, immediately E, has several nested craters. The fumaroles and boiling mudpots of Hervideros de San Jacinto, SE of Telica, form a prominent geothermal area frequented by tourists, and geothermal exploration has occurred nearby.

References:

¹ Smithsonian Institution / US Geological Survey Weekly Volcanic Activity Report – GVP – January 1 -7, 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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