講演情報
[SSS09-P04]Post-seismic deformation of 2016 Kumamoto Earthquake by continuous GNSS network (2)
*中尾 茂1、松島 健2、田部井 隆雄3、大久保 慎人4、山品 匡史4、大倉 敬宏5、西村 卓也6、澁谷 拓郎6、寺石 眞弘6、伊藤 武男7、鷺谷 威8、松廣 健二郎7、加藤 照之9、福田 淳一9、渡邉 篤志9、三浦 哲10、太田 雄策10、出町 知嗣10、高橋 浩晃11、大園 真子11、山口 照寛11、岡田 和見11 (1.鹿児島大学大学院理工学研究科地球環境科学専攻、2.九州大学大学院理学研究院附属地震火山観測研究センター、3.高知大学理工学部地球環境防災科学科、4.高知大学理工学部附属高知地震観測所、5.京都大学大学院理学研究科附属地球熱学研究施設火山研究センター、6.京都大学防災研究所、7.名古屋大学大学院環境学研究科附属地震山研究センター、8.名古屋大学減災連携研究センター、9.東京大学地震研究所、10.東北大学大学院理学研究科附属地震・噴火予知研究観測センター、11.北海道大学大学院理学研究院附属地震火山研究観測センター)
キーワード：
GNSS連続観測、余効変動、2016年熊本地震
Post-seismic deformation has been observed since April 15, 2016 by extraordinary GNSS observations of 20 sites and cooperative GNSS observations of 15 sites by Kyushu University, Kyoto University and Kagoshima University. Extraordinary GNSS sites started observation in April, 2016 after occurrence of 2016 Kumamoto Earthquake. Cooperative GNSS observations have observed continuously before the earthquake. Bernese GNSS Software V. 5.2 are used for GNSS data analysis with GEONET data, which is operated by GSI and JMA GNSS continuous data in Kyushu. CODE precise ephemerides and Earth rotation pole data are used.
Plate motion in each site should be removed from post-seismic deformation data. Displacement velocities of GNSS sites are estimated by Least Squares method in the period from 2004 to 2013. Displacement velocities of extraordinary GNSS sites are interpolated by velocities around the sites. Post-seismic deformation is derived by extracting the displacement velocity of plate motion.
Post-seismic deformation is observed at sites which are located on the south-east side of Hinagu fault, especially on NS component until December 2017. It seems that clear post-seismic deformation continues until early part of June, 2016 at sites which are located on the north-west side of Hinagu faults. Change in NS component around May, 2017 and in EW component around August, 2017 occurred at sites which are located on both sides of Hinagu fault.
Plate motion in each site should be removed from post-seismic deformation data. Displacement velocities of GNSS sites are estimated by Least Squares method in the period from 2004 to 2013. Displacement velocities of extraordinary GNSS sites are interpolated by velocities around the sites. Post-seismic deformation is derived by extracting the displacement velocity of plate motion.
Post-seismic deformation is observed at sites which are located on the south-east side of Hinagu fault, especially on NS component until December 2017. It seems that clear post-seismic deformation continues until early part of June, 2016 at sites which are located on the north-west side of Hinagu faults. Change in NS component around May, 2017 and in EW component around August, 2017 occurred at sites which are located on both sides of Hinagu fault.