摘要
利用GRACE卫星RL05时变重力场模型,计算2011年3月11日日本9.0级大地震震源区及周边地区前后1个月、6个月和1年的重力变化情况,发现在震前数年已出现的正负交替现象在震前1年内变得更加明显。计算了基于地震位错理论的同震重力变化并向上延拓至卫星高度,结果表明重力卫星可以清晰地探测到该震的同震重力变化。分析震源区周边4个特征点时间序列变化,结合GMT最佳双力偶震源机制,发现两者揭示的震源区周边物质动力变化状态具有一致性。
Gravity changes in the earthquake source area and the surrounding area before and after 1 month, 6 months and 1 year of Japan MW9.0 earthquake on March 11, 2011 were calculated by using GRACE RL05 time variable gravity field models.We find that a plus or minus alternate phenomenon is more obvious within 1 year before the earthquake. By calculating the coseismic gravity changes based on the earthquake dislocation theory and these of upward continuation to the satellite altitude, the results show that the coseismic gravity changes of the earthquake can be clearly detected by the GRACE satellite. Combined with the GMT best double couple focal mechanism, time series gravity changes of four feature points in the surrounding region are analyzed. We find that dynamic change status of surrounding material of the focal region revealed by the two methods are consistent.
出处
《大地测量与地球动力学》
CSCD
北大核心
2013年第5期1-6,共6页
Journal of Geodesy and Geodynamics
基金
中国地震局基本科研业务费专项(IS201116022)
国家自然科学基金(40704009
41004030
41004010)
关键词
卫星重力
断层模型
重力变化
向上延拓
震源机制解
satellite gravity
fault model
gravity changes
upward continuation
focal mechanism solution
