Report on Nishinoshima (Japan) — 9 July-15 July 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 9 July-15 July 2014
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2014. Report on Nishinoshima (Japan). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 9 July-15 July 2014. Smithsonian Institution and US Geological Survey.
27.247°N, 140.874°E; summit elev. 25 m
All times are local (unless otherwise noted)
Tokyo VAAC reported volcanic ash from Nishinoshima at 3 km (10,000 ft) a.s.l. at 2203 on 30 June; the plume extended NE. However, ash was not visible in satellite images. The University of Hawaii reported that Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data detected thermal anomalies and issued MODVOLC alerts during 25 June-13 July with the exceptions of 8, 11, and 12 July.
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.