Roundup of Global Volcanic Activity – Ongoing activity for the week 8 March – 14 March 2023

Ahyi – Mariana Islands (USA) : Unrest at Ahyi Seamount continued during 8-14 March. A few events per day were detected by pressure sensors on Wake Island, 2,270 km E, during 7-11 March. Almost continuous hydroacoustic signals from roughly the direction of Ahyi were recorded by the sensors during 11-13 March, and then signals stopped abruptly on 14 March. Discolored water was visible in satellite images during 12-14 March; the discoloration extended about 35 km at the end of the week.

Aira – Kyushu (Japan) : JMA reported ongoing eruptive activity at Minamidake Crater and Showa Crater (at Aira Caldera’s Sakurajima volcano) during 6-13 March. Incandescence at Minamidake was visible nightly. Five eruptive events at Minamidake were recorded and explosions occurred on 8 and 11 March. Ash plumes rose as high as 1.7 km above the crater rim, and during 10-13 March large blocks were ejected as far as 500 m from the vent. Seven eruptive events occurred at Showa during 6-10 March, producing ash plumes that rose as high as 2.7 km above the crater rim and ejecting large blocks 800 m from the crater.

Chiles-Cerro Negro – Colombia-Ecuador : A seismic swarm at the Cerro Negro de Mayasquer and Chiles volcanoes, called the Chiles-Cerro Negro volcanic complex (CCNVC), began on 9 March according to the Instituto Geofísico de la Escuela Politécnica Nacional (IGEPN) and the Observatorio Vulcanológico de Pasto (OVP-Colombia). A noted increase in the intensity of seismic signals occurred at 0430 and was followed by an increase in the number of volcano-tectonic events (indicating fracturing rock) at 0900. By 1630, there were around 2,200 earthquakes recorded by the seismic network, and 520 of those events had epicenters located within 2.5 km S of Chiles at depths of 1-6 km below the summit (4,700 m elevation). The swarm was accompanied by deformation which was first detected on 28 February. The swarm intensified during 9-10 March, and 86 earthquakes were above M2. At 2010 on 9 March a M 3.4 earthquake was felt by residents in nearby towns in both Colombia and Ecuador; earthquakes recorded at 0137 and 0526 on 10 March were also felt. On 10 March earthquakes were occurring at a rate of around 200 events per hour and were mostly comprised of volcano-tectonic events (indicating fracturing rock) and very-low-frequency earthquakes (indicating fluid movement). At least 4,500 events had been recorded by 1214 on 10 March. There were 4,244-4,915 daily earthquakes during 11-13 March.

Cotopaxi – Ecuador : IG reported that the eruption at Cotopaxi continued during 8-14 March. Gas-and-steam emissions were visible on most days rising as high as 1.5 km above the crater rim and drifting in multiple directions. On 10 March a gas-and-steam plume with low ash content rose as high as 1 km and drifted S. Weather clouds sometimes prevented observations, especially on 11 March.

Ebeko – Paramushir Island (Russia) : KVERT reported that moderate activity at Ebeko was ongoing during 2-9 March. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions during 3, 5-7, and 9 March generated ash plumes that rose as high as 3.6 km (11,800 ft) a.s.l. and drifted E. A thermal anomaly was identified in satellite images on 7 and 9 March. Ashfall was reported in Severo-Kurilsk on 3 March.

Great Sitkin – Andreanof Islands (USA) : AVO reported that slow lava effusion at Great Sitkin likely continued during 8-14 March. Satellite images and web camera views were mostly cloudy, though elevated surface temperatures were identified in satellite images during 8-9 March. Seismicity was low.

Krakatau – Sunda Strait : The Darwin VAAC reported that during 1240-1300 on 10 March continuous ash emissions from Anak Krakatau rose 1.5-1.8 km (5,000-6,000 ft) a.s.l. and drifted W and NW based on satellite images, weather models, and PVMBG webcams. Only steam-and-gas emissions were visible on webcam images on 11 March.

Lewotolok – Lembata Island : PVMBG reported that the eruption at Lewotolok was ongoing during 8-14 March. Daily white gas-and-steam plumes rose as high as 700 m above the summit and drifted in multiple directions. A few webcam images posted with the observatory reports showed incandescence at the summit.

Sabancaya – Peru : Instituto Geofísico del Perú (IGP) reported moderate levels of activity at Sabancaya during 27 February-5 March with a daily average of 46 explosions. Gas-and-ash plumes rose as high as 2.6 km above the summit and drifted NW, W, and SW. Four thermal anomalies originating from the lava dome in the summit crater were identified in satellite data.

San Miguel – Eastern El Salvador : MARN reported increased emissions at San Miguel during 7-9 March. Gas emissions began increasing along with seismicity at 2252 on 7 March and were continuous at least through the morning of 8 March. A total of 12 emissions were recorded, with the last one occurring at 1210 on 9 March. Some of the gas emissions contained ash, with the most intense period causing minor ashfall in El Tránsito (10 km S), La Morita (6 km W), and La Piedrita (3 km W), and a sulfur odor in Piedra Azul (5 km SW).

Semeru – Eastern Java : PVMBG reported that the eruption at Semeru continued during 8-14 March. Weather clouds sometimes prevented views of the volcano, though ash plumes were visible each day. On 8 March white-and-gray ash plumes that were sometimes dense rose as high as 300-700 m above the summit and drifted N and NE. During 9-10 March dense white, gray, and brown ash plumes rose 500-600 m and drifted SW and S. At least six white-and-gray ash plumes of variable densities were visible on 11 March rising 600-800 m and drifting N, W, and S. White-and-gray ash plumes rose 500-700 m and drifted N, NE, and SW during 12-14 March.

Sheveluch – Central Kamchatka (Russia) : KVERT reported that the ongoing eruption at Sheveluch was generally characterized by explosions, hot avalanches, lava-dome extrusion, and strong fumarolic activity. A daily thermal anomaly was identified in satellite images during 2-9 March and ash plumes drifted as far as 118 km E during 4-5 March.

Suwanosejima – Ryukyu Islands (Japan) : JMA reported that the eruption at Suwanosejima’s Ontake Crater continued during 6-13 March. A total of 18 explosions were recorded, sending ash plumes as high as 2.3 km above the crater rim and ejecting large blocks as far as 400 m from the vent. Crater incandescence was visible at night. Occasional ashfall was reported in Toshima village (3.5 km SSW). On 8 March grayish-white plumes were seen rising from the vent during an overflight. No other changes were noted compared to the last overflight conducted on 29 September 2022.

Villarrica – Central Chile : SERNAGEOMIN reported that the eruption at Villarrica was ongoing during 8-14 March. Webcam images on 13 March showed incandescence above the crater rim from Strombolian activity.

Whakaari/White Island – North Island (New Zealand) : On 10 March GeoNet reported continuing unrest at Whakaari/White Island characterized by significant gas-and-steam emissions and increasing gas emissions. Significant amounts of steam and gas at temperatures of around 240 degrees Celsius were measured during an observation flight on 2 March and a gas flight on 9 March. Gas emissions had increased but remained within normal limits. Large steam plumes, which were likely enhanced due to weather conditions, were visible from the mainland rising above the volcano on 5 March. Significant rain during the previous month raised the water levels in the crater lake and some of the smaller pools; geysering and bubbling from underwater fumaroles was visible.

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