Detections of sub-micro-gal gravity changes associated with earthquakes and volcanism, revealed by precise corrections of hydrological gravity disturbances

2014 Fiscal Year Final Research Report

• Project/Area Number: 25887035
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Solid earth and planetary physics
• Research Institution: Kyoto University
• Principal Investigator: KAZAMA Takahito 京都大学, 理学(系)研究科(研究院), 助教 (20700363)
• Project Period (FY): 2013-08-30 – 2015-03-31
• Keywords: 重力観測 / 地震 / 火山活動 / 陸水擾乱 / 桜島 / 浅間山 / 地下水 / 土壌水分

Outline of Final Research Achievements

In order to obtain gravity changes associated with spatiotemporal mass variations due to earthquakes and volcanic activities, we corrected observed gravity data for hydrological gravity disturbances with a high degree of precision. For Sakurajima Volcano, we reproduced the hydrological disturbances of the observed relative gravity data within 8 micro-gal, using an empirical hydrological model. For Asama Volcano, we retrieved the 5-micro-gal gravity signal due to magma movement during the 2004 eruptions, by correcting the hydrological disturbances observed by absolute gravimeters using a physical hydrological model. Gravity measurements will enable us to monitor mass redistributions related to earthquakes and volcanism, by means of these hydrological models for the hydrological disturbance corrections.

Free Research Field

測地学