Report on Nishinoshima (Japan) — 25 January-31 January 2023
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
25 January-31 January 2023
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2023. Report on Nishinoshima (Japan). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 25 January-31 January 2023. Smithsonian Institution and US Geological Survey.
27.247°N, 140.874°E; summit elev. 25 m
All times are local (unless otherwise noted)
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.
Geological Summary. 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.
Source: Japan Coast Guard