Report on Nishinoshima (Japan) — 16 December-22 December 2020
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 16 December-22 December 2020
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2020. Report on Nishinoshima (Japan). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 16 December-22 December 2020. Smithsonian Institution and US Geological Survey.
27.247°N, 140.874°E; summit elev. 25 m
All times are local (unless otherwise noted)
JMA reduced the exclusion zone for Nishinoshima from a radius of 2.5 to 1.5 km around the summit crater on 18 December; eruptive activity ended in August. Fumarolic and high-temperature areas remained visible.
Geologic Background. The small island of Nishinoshima was enlarged when several new islands coalesced during an eruption in 1973-74. Another eruption that began offshore in 2013 completely covered the previous exposed surface and enlarged the island again. Water discoloration has been observed on several occasions since. The island is the summit of a massive submarine volcano that has prominent satellitic peaks to the S, W, and NE. The summit of the southern cone rises to within 214 m of the sea surface 9 km SSE.