Volcanos

Roundup of Global Volcanic Activity - New Activity for the week 25 January - 31 January 2023

Asosan - Kyushu (Japan) : JMA reported that the amplitude of volcanic tremor signals at Asosan increased at around 1200 on 30 January and then increased again around 1220 and remained high.

Chikurachki - Paramushir Island (Russia) : KVERT reported that an explosive eruption at Chikurachki likely began at 0630 on 29 January. Ash plumes rose to as high as 3 km (10,000 ft) a.s.l. and drifted 75 km SE based on satellite data. At 1406 and 1720 ash plumes were identified in satellite images rising to 4.3 km (14,000 ft) a.s.l. and drifting 70 km E. Ash plumes had dissipated by 2320.

Epi - Vanuatu : The Wellington VAAC reported that a low-level plume of ash and sulfur dioxide from a new eruption at Epi was identified in satellite data at 0730 on 31 January. According to the Vanuatu Meteorology and Geo-Hazards Department (VMGD) residents saw steaming at the ocean’s surface in the area over the vents at around 0748, and phreatic explosions that ejected steam and tephra 100 m above the water. Observers reportedly saw a growing cone from ongoing ash emissions. The VAAC noted that the eruption was short-lived and had ceased by 1548; the ash had dissipated. Three submarine cones, Epi A, Epi B, and Epi C, and smaller cones and craters, are located 10-16 km NNE from the summit of Epi Island and are aligned along the N rim of an inferred caldera. Epi B is the shallowest of the seamounts and has been historically active, most recently in February 2004. A March 2004 bathymetric survey revealed that Epi B was about 300 m tall, with a diameter of about 1.8 km at the base. The summit crater was about 150 m in diameter and the crater floor was at a depth of 90 m. The highest point was on the NW rim of the summit crater, at a depth of 34 m.

Erta Ale - Ethiopia : Small thermal anomalies in both of Erta Ale’s N and S pit craters were identified in satellite images on 23 January. On 28 January the anomaly in the N pit crater was large and intense.

Lascar - Northern Chile : SERNAGEOMIN reported increased seismicity at Láscar on 26 January with long-period (LP) events indicating fluid movement at shallower depths. ONEMI declared an Alert Level Yellow (the middle level on a three-color scale) for San Pedro de Atacama (70 km NW). A seismic signal at 2259 corresponded to the ejection of incandescent material and the emission of a plume that likely contained tephra and rose almost 1.9 km and drifted NW. The intensity of LP events significantly increased at 2300 on 27 January and remained at anomalous levels. A series of four LP events were recorded at 0015, 0032, 0043, and 0052 on 28 January and corresponding emissions rose 380 m above the crater rim and drifted NW. An M 3.2 volcano-tectonic earthquake was recorded at 0115 and felt by residents. LP earthquakes continued to be detected, along with tremor and volcano-tectonic events to a lesser extent. Minor crater incandescence was visible and gas plumes rose as high as 760 m. Elevated levels of seismicity continued to be detected during 28-30 January. Whitish-gray gas plumes possibly containing tephra rose to low heights and minor crater incandescence was occasionally observed. On 31 January SERNAGEOMIN stated that a satellite image from the day before showed a dome-like feature on the crater floor that was 81 m by 93 m in dimension and covered an area of about 5,332 square meters. The exclusion zone was increased to 10 km.

Myojinsho - Izu Islands : According to JMA an area of pale yellow-green discolored water with a diameter of about 100 m was visible about 65 km SSE of Myojinsho on 26 January, based on an overflight conducted by the Japan Coast Guard. An eruption warning was issued to mariners. Discolored water was last observed in March 2017.

Nishinoshima - Izu Islands : The Japan Coast Guard reported that during an overflight of Nishinoshima on 25 January scientists observed intermittent activity and small, blackish-gray plumes rising 900 m from the central part of the crater. The fumarolic zone on the E flank and base of the cone had expanded and emissions had intensified. Dark brown discolored water was visible all around the volcanic island.