Name : NIRATA,  Naoshi
            Position : Professor
            Division/Center : Earthquake Observation Center
            Research Area : Observational Seismology
 

RESEARCH

-  Heterogeneity in the crust. The study includes researches on the spatial and temporal distribution of micro earthquakes with specialattention 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

Matsubara, M., N. Hirata, S. Sakai, and I. Kawasaki, A low velocity zone beneath the Hida Mountains derived from dense array observation and tomographic method, Earth Planets Space, 52, 143--154, 2000.

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.

Nakao, S., C-C. Liu, Y. Hirata, S-B Yu, and N. Hirata, Observations of Postseismic Crustal deformation Following the 1999 Chi-Chi, Taiwan Earthquake Using a Dense GPS Array, Bull. Earthq. Res. Inst. Univ. Tokyo, 75, 1, 47--56, 2000.