{"created":"2023-03-31T02:00:25.175659+00:00","id":4680,"links":{},"metadata":{"_buckets":{"deposit":"5113a2f2-d00a-4ab5-9340-6719a6db87e5"},"_deposit":{"id":"4680","owners":[1],"pid":{"revision_id":0,"type":"depid","value":"4680"},"status":"published"},"_oai":{"id":"oai:nied-repo.bosai.go.jp:00004680","sets":[]},"author_link":[],"item_10001_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2013","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"1","bibliographicPageEnd":"251","bibliographicPageStart":"238","bibliographicVolumeNumber":"193","bibliographic_titles":[{"bibliographic_title":"Geophysical Journal International","bibliographic_titleLang":"ja"},{"bibliographic_title":"Geophysical Journal International","bibliographic_titleLang":"en"}]}]},"item_10001_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"We detect time-lapse changes in P- and S-wave velocities (hereafter, V-P and V-S, respectively) and shear wave splitting parameters associated with the 2011 Tohoku earthquake, Japan, at depths between 0 and 504 m. We estimate not only medium parameters but also the 95 per cent confidence interval of the estimated velocity change by applying a new least squares inversion scheme to the deconvolution analysis of KiK-net vertical array records. Up to 6 per cent V-S reduction is observed at more than half of the analysed KiK-net stations in northeastern Japan with over 95 per cent confidence in the first month after the main shock. There is a considerable correlation between the S-wave traveltime delay and the maximum horizontal dynamic strain (MDS) by the main shock motion when the strain exceeds 5 x 10(-4) on the ground surface. This correlation is not clearly observed for MDS at the borehole bottom. On the contrary, V-P and shear wave splitting parameters do not show systematic changes after the Tohoku earthquake. These results indicate that the time-lapse change is concentrated near the ground surface, especially in loosely packed soil layers. We conclude that the behaviour of V-P, V-S and shear wave splitting parameters are explained by the generation of omnidirectional cracks near the ground surface and by the diffusion of water in the porous subsurface. Recovery of V-S should be related to healing of the crack which is proportional to the logarithm of the lapse time after the main shock and/or to decompaction after shaking.","subitem_description_language":"en","subitem_description_type":"Other"}]},"item_10001_publisher_8":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"OXFORD UNIV PRESS","subitem_publisher_language":"en"}]},"item_10001_relation_14":{"attribute_name":"DOI","attribute_value_mlt":[{"subitem_relation_type_id":{"subitem_relation_type_id_text":"10.1093/gji/ggs080"}}]},"item_10001_source_id_9":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"0956-540X","subitem_source_identifier_type":"ISSN"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"SAWAZAKI Kaoru","creatorNameLang":"ja"},{"creatorName":"SAWAZAKI Kaoru","creatorNameLang":"en"}]},{"creatorNames":[{"creatorName":"SAWAZAKI Kaoru","creatorNameLang":"ja"},{"creatorName":"SAWAZAKI Kaoru","creatorNameLang":"en"}]},{"creatorNames":[{"creatorName":"SNIEDER Roel","creatorNameLang":"ja"},{"creatorName":"SNIEDER Roel","creatorNameLang":"en"}]}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"item_title":"Time-lapse changes of P- and S-wave velocities and shear wave splitting in the first year after the 2011 Tohoku earthquake, Japan: shallow subsurface","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Time-lapse changes of P- and S-wave velocities and shear wave splitting in the first year after the 2011 Tohoku earthquake, Japan: shallow subsurface","subitem_title_language":"ja"},{"subitem_title":"Time-lapse changes of P- and S-wave velocities and shear wave splitting in the first year after the 2011 Tohoku earthquake, Japan: shallow subsurface","subitem_title_language":"en"}]},"item_type_id":"40001","owner":"1","path":["1670839190650"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2023-03-30"},"publish_date":"2023-03-30","publish_status":"0","recid":"4680","relation_version_is_last":true,"title":["Time-lapse changes of P- and S-wave velocities and shear wave splitting in the first year after the 2011 Tohoku earthquake, Japan: shallow subsurface"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2023-06-08T06:07:50.679518+00:00"}