Study on precursory ground deformation of a phreatic eruption by SAR observation and numerical simulation

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K17797
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Solid earth and planetary physics
• Research Institution: Geospatial Information Authority of Japan (Geography and Crustal Dynamics Research Center)
• Principal Investigator: Kobayashi Tomokazu 国土地理院(地理地殻活動研究センター), その他部局等, 主任研究官 (40447991)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 前駆的地殻変動 / 水蒸気噴火 / 箱根・大涌谷 / 干渉SAR時系列解析

Outline of Final Research Achievements

I have successfully detected precursory inflational ground deformation for the 2015 Hakone volcano eruption by conducting SAR data analysis. The ground inflation proceeded in the early stage; since the end of 2014 at the latest, and then, it accelerated two months before the eruption. Finally the eruption occurred nearby the most deformed part. To further discuss the mechanism of the local deformation, I computed the spatial distribution and the time evolution on pressure and temperature within the volcano body, with taking the magma supply system of the Hakone volcano into account. The numerical simulation showed that a mineralogical conduit sealing could accumulate heat and pressure under the geothermal area, resulting in the local ground deformation prior to the eruption.

Free Research Field

測地学