日本地球惑星科学連合2019年大会

講演情報

[E] 口頭発表

セッション記号 M (領域外・複数領域) » M-IS ジョイント

[M-IS04] Interdisciplinary studies on pre-earthquake processes

2019年5月30日(木) 13:45 〜 15:15 A02 (東京ベイ幕張ホール)

コンビーナ:服部 克巳(千葉大学大学院理学研究科)、劉 正彦(国立中央大学太空科学研究所)、Ouzounov Dimitar(Center of Excellence in Earth Systems Modeling & Observations (CEESMO) , Schmid College of Science & Technology Chapman University, Orange, California, USA)、Qinghua Huang(Peking University)、座長:Jann-Yenq Liu(National Central University, Taiwan)、長尾 年恭

14:45 〜 15:00

[MIS04-05] The S-K characteristics of the borehole areal strains associated with the Ms 8.0 Wenchuan and Ms 7.0 Lushan earthquakes

★Invited Papers

*Kaiguang Zhu 1Zining Yu1Chenquan Chi1Mengxuan Fan1Kaiyan Lii1 (1.Jilin University )

キーワード:borehole areal strain、S-K biases、S-K distributions、Wenchuan and Lushan earthquakes

The skewness and kurtosis of daily borehole areal strain at Guza station are jointly analysed on the S-K plane for the Wenchuan and Lushan earthquakes. We define a crustal stationary background to distinguish possible anomalies related to the earthquakes on the assumption that the background exhibits a quasi-Gaussian distribution. By calculating the S-K biases of the daily areal strain from the crustal stationary background, we found that before the Wenchuan earthquake, the large S-K bias anomalies were always negative, implying that the crust was compressed near the station. Whereas for the Lushan earthquake, clustered positive bias anomalies appeared within two time periods, revealing tensile changes in the crust. In addition, the S-K distributions of two arthquakes are separated on the S-K plane, further indicating differences in the associated deformation. These results demonstrate that the S-K characteristics of borehole areal strain data are potentially promising as earthquake precursors.