Last Update 05/27 2014
Research: * Heterogeneity in the crust: The study includes researches on the spatial and temporal distribution of micro earthquakes with special attention to heterogeneity of the Earth\\\\\\\'s crust. The methods includes intensive field seismic observations. I have conducted several observation of aftershocks of a large earthquake, including the 1995 Hyogo-ken Nanbu, Kobe, earthquake, and swarm activities in the Izu Peninsula, and aftershocks of the 1999 Chi-Chi, Taiwan earthquake. * Structure and development of the island-arc crust: Study of the evolution of the crustal structure by the observational method of active and passive seismic sources. The goal of the study is to understand dynamic structure of the Japanese island-arc-trench system which causes large earthquakes. I have conducted a seismic experiment in Tohoku and Hokkaido, the northern Japan, to understand a deep structureof the active fault system. The study is aimed to develop a understanding of deformation process of the Japanese island-arc. Publications: 蔵下英司，徳永雅子，平田 直，岩崎貴哉，小平秀一，金田義行，伊藤 潔，西田良平，木村昌三，井川 猛, 四国東部地域における地殻及び最上部マントルの地震波速度構造と沈み込むフィリピン海プレートの形状, 地震2, 54, 4, 489--505, 2002. Sato, H., N.Hirata, T. Iwasaki, M. Matsubara and T. Ikawa, Deep seismic reflection profiling across the Ou Backbone range, northern Honshu Island, Japan, Tectonophysics, 355, 1-4, 41--52, 2002. 飯尾能久・松澤 暢・吉田真吾・加藤照之・平田 直, 非地震性すべりの時空間変化と大地震の発生予測 −三陸沖における近年の進展を中心に−, 地震2, 56, 2, 213--229, 2003. Hirata, N., Past, current and future of Japanese national program for earthquake prediction research, Earth Planets Space, 56, 8, xliii--l, 2004. Matsubara, M., N. Hirata, H. Sato, and S. Sakai, Lower crustal fluid distribution in the northeastern Japan arc revealed by high-resolution 3D seismic tomography, Tectonophysics, 388, 1-4, 33--45, 2004. Nakagawa, S., N. Hirata, and H. Sato, Imaging of the crust using aftershocks of the 2000 western Tottori prefecture earthquake, Geophys. Res. Lett., 32, L10310, doi:10.1029/2004GL022332, , 2005. Sato, H., N., Hirata, K. Koketsu, D. Okaya, S. Abe, R. Kobayashi, M. Matsubara, T. Iwasaki, T. Ito, T. Ikawa, T. Kawanaka, K. Kasahara, S. Harder,, Earthquake Source Fault Beneath Tokyo, Science, 309, 5733, 462--464, 2005. Kato, A., S. Sakai, N. Hirata, E. Kurashimo, T. Iidaka, T. Iwasaki, and T. Kanazawa, Imaging the seismic structure and stress field in the source region of the 2004 mid-Niigata prefecture earthquake: Structural zones of weakness and seismogenic stress concentration by ductile flow, J. Geophys. Res.111, B08308, doi:10.1029/2005JB004016., , 2006. Wu, F., D. Okaya, H. Sato, and N. Hirata, Interaction between two subducting plates under Tokyo and its possible effects on seismic hazards, Geophys. Res. Lett., 34, L18301, doi:10.1029/2007GL030763, , 2007. 平田直, 日本の地震予知研究−地震予知のための観測研究計画−, 地震2, 61, 特集号, S592--S601, 2009. Kato, A., K. Obara, T. Igarashi, H. Tsuruoka, S. Nakagawa and N. Hirata, Propagation of Slow Slip Leading Up to the 2011Mw 9.0 Tohoku-Oki Earthquake, Science, 335, 705--708, 2011. Nanjo, K. Z., S. Sakai, A. Kato, H. Tsuruoka, N. Hirata, Time-dependent earthquake probability calculations for southern Kanto after the 2011 M9.0 Tohoku earthquake, Geophys. J. Int., 193, 914--919, 2013. Hirata, N., S. Sakai, Z-S. Liaw, Y-B. Tsai, and S-B Yu, Aftershock Observation of the 1999 Chi-Chi, Taiwan Earthquake, Bull. Earthq. Res. Inst. Univ. Tokyo, 75, 1, 33--46, 2000. 平田直, 日本の地震予知研究の到達点と第2次新地震予知研究計画, 科学, 73, 9, 1020--1028, 2003. 平田直・佐藤比呂志・能登半島地震合同余震観測グループ, 2007年能登半島地震の意味‐防災のための活断層の考え方‐, 科学, 77, 6, 562--566, 2007. 平田直・佐藤比呂氏・酒井慎一・加藤愛太郎, 2007年新潟県中越沖地震の震源断層 −大地震をおこす「長岡平野西縁断層帯」と関係するか, 科学, 77 , 9, 930--934, 2007. 平田直, 地殻ダイナミクスと地震発生（分担、菊地正幸編）, 朝倉書店, 2002. 平田直・佐竹健治・目黒公郎・畑村洋太郎, 巨大地震・巨大津波 −東日本大震災の検証-, 朝倉書店, 2011. |
