Report on Kuchinoerabujima (Japan) — 5 February-11 February 2020
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 5 February-11 February 2020
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2020. Report on Kuchinoerabujima (Japan). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 5 February-11 February 2020. Smithsonian Institution and US Geological Survey.
30.443°N, 130.217°E; summit elev. 657 m
All times are local (unless otherwise noted)
JMA reported that after the 3 February eruption at Kuchinoerabujima’s Shindake Crater the number of volcanic earthquakes decreased, and very small eruptive events occurred intermittently though 5 February and on 9 February. A large amount of ashfall (including lapilli up to 2 cm in diameter) was confirmed on the SE flank during field observations on 3 and 6 February. Thermal image observations revealed 5-km-long pyroclastic flow deposits on the SW flank. The number of volcanic earthquakes began increasing on 9 February and continued to be elevated the next day. A large-amplitude volcanic tremor event was accompanied by fluctuating tilt at 1318 on 11 February. The Alert Level remained at 3 (the middle level on a scale of 1-5).
Geologic Background. A group of young stratovolcanoes forms the eastern end of the irregularly shaped island of Kuchinoerabujima in the northern Ryukyu Islands, 15 km W of Yakushima. The Furudake, Shindake, and Noikeyama cones were erupted from south to north, respectively, forming a composite cone with multiple craters. The youngest cone, centrally-located Shindake, formed after the NW side of Furudake was breached by an explosion. All historical eruptions have occurred from Shindake, although a lava flow from the S flank of Furudake that reached the coast has a very fresh morphology. Frequent explosive eruptions have taken place from Shindake since 1840; the largest of these was in December 1933. Several villages on the 4 x 12 km island are located within a few kilometers of the active crater and have suffered damage from eruptions.