Report on Nishinoshima (Japan) — 5 July-11 July 2023
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 5 July-11 July 2023
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2023. Report on Nishinoshima (Japan) (Sennert, S, ed.). Weekly Volcanic Activity Report, 5 July-11 July 2023. Smithsonian Institution and US Geological Survey.
27.247°N, 140.874°E; summit elev. 100 m
All times are local (unless otherwise noted)
JMA reported that at around 1300 on 9 July an eruption plume from Nishinoshima rose 1.6 km above the crater and drifted N. Satellite images acquired at 1420 and 2020 on 9 July and 0220 on 10 July showed continuing emissions rising 1.3-1.6 km and drifting NE and N.
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 ocean surface 9 km SSE.