Geospatial Information Authority of Japan (GSI) took aerial photographs of the area around Nishinoshima Island on December 9th, 2015 using its survey airplane “Kunikaze III”. GSI measured area, highest elevation and volume, and these results are publicly available now.
These photographs of the Ogasawara islands were taken at the beginning of December with the cooperation of the Ministry of Defense, and the area around Nishinoshima Island was photographed on December 9th (Attachment 1).
Through the analysis of aerial photographs and orthophotographs taken of the area around Nishinoshima Island, the following results were obtained.
The area was approximately 2.71 square kilometers (unofficial value). This was slightly decreased by approximately 0.03 square kilometers compared with the area of 2.74 square kilometers measured on July 28th, 2015.
The total volume of lava over the sea level emitted and accumulated after the first eruption in November 2013 was approximately 88,010,000 cubic meters (unofficial value). This represented an increase of approximately 2,900,000 cubic meters compared with the volume of 85,110,000 cubic meters measured on July 28th, 2015
The elevation of highest point was approximately 142 meters (unofficial value). This is approximately 8 meters lower than that of 150 meters (unofficial value) measured on July 28th, 2015.
Professor Setsuya Nakada, Earthquake Research Institute, The University of Tokyo,(Leader of The Nishinoshima General Observation Team, Coordinating Committee for Prediction of Volcanic Eruption) gave comments on the survey results (Attachment 5)
The present aerial photographs and related information are being published on the Internet under “GSI Maps”(in Japanese).