Volcanos

Roundup of Global Volcanic Activity – New Activity for the week of 14 March - 20 March 2018

Ambae | Vanuatu : On 18 March the Vanuatu Geohazards Observatory (VGO) reported that eruptive activity at Ambae’s Lake Voui during February-March was similar to activity observed at the end of October 2017, but with more sustained ash emissions from explosions at the vent. The ongoing ash-and-gas emissions were impacting local villages, prompting VGO to raise the Alert Level to 3 (on a scale of 0-5) and to warn residents and tourists to stay outside of the Danger Zone defined as a 3-km radius around the active vent in Lake Voui. A news article noted that ashfall was reported in the NW, W, SW, and S parts of the island.

Kick 'em Jenny | North of Grenada : The University of the West Indies (UWI) Seismic Research Centre (SRC) and the National Disaster Management Agency (NaDMA) reported that during 12-15 March seismicity at Kick 'em Jenny significantly decreased. The Alert Level remained at Orange (the second highest level on a four-colour scale) with a 5-km maritime exclusion zone.

Kikai | Japan : JMA reported that one small-amplitude, short-duration volcanic tremor was detected on 16 March at Satsuma Iwo-jima, a subaerial part of Kikai’s NW caldera rim. The number of volcanic earthquakes increased on 19 March, prompting JMA to raise the Alert Level to 2 (on a 5-level scale), and then decreased the next day. The report noted increased thermal activity since February, with occasional visual observations of incandescence.

Kirishimayama | Kyushu (Japan) : JMA reported that the eruption at Shinmoedake (Shinmoe peak), a stratovolcano of the Kirishimayama volcano group, continued during 13-19 March. Lava effusion possibly stopped on 9 March, though the lava flow on the NW flank continued to advance. An explosion at 1413 on 15 March generated a gray-white plume that rose 2.1 km above the crater and ejected material 1 km from the crater. A high number of volcanic earthquakes continued to be recorded, in addition to many low-frequency earthquakes with shallow hypocenters. Volcanic tremor was occasionally recorded. The Alert Level remained at 3 (on a scale of 1-5).

Stromboli | Aeolian Islands (Italy) : INGV reported that during 12-17 March activity at Stromboli was at normal levels, characterized by explosive activity and gas emissions from two vents (N1 and N2) in Area N and two vents in Area C-S (C and S2). Explosions at N1 ejected lapilli, bombs, and sometimes ash less than 120 m high, and less intense explosions at N2 emitted ash no higher than 80 m. The frequency of explosions in Area N was 3-8 events/hour. Continuous gas emissions rose from C. Explosions at S2 emitted ash no higher than 80 m at a rate of 2-5 explosions/hour. A high-energy explosive sequence began at vent C at 2027 on 19 March and lasted about 40 seconds. The first explosion ejected ash and incandescent material that fell in a radial distribution around the crater. Two subsequent explosions ejected incandescent material as high as 80 m. Tephra fell along the Sciara del Fuoco, towards the NE parts of the island. At 2028 an explosion at N2 ejected lapilli 100-120 m high.