Report on Nishinoshima (Japan) — 18 July-24 July 2018
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 18 July-24 July 2018
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2018. Report on Nishinoshima (Japan). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 18 July-24 July 2018. Smithsonian Institution and US Geological Survey.
27.247°N, 140.874°E; summit elev. 25 m
All times are local (unless otherwise noted)
Based on Japan Coast Guard (JCG) observations, JMA reported that a very small eruption at Nishinoshima occurred at 1124 on 12 July, producing a brownish plume that rose from near the crater. During an aerial survey, JCG noted deposits 400 m from the vent. No thermal anomalies were detected. The report warned people to stay at least 500 m away from the crater.
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.