Last Update 08/30 2003
Research: The complexity of earthquake sources is often modeled in terms of asperities and barriers. In an attempt to extract such a heterogeneity, I developed a useful technique to analyse seismic data. So far I have modeled many earthquakes with various sizes and depths, using the data recorded at local and global networks of broadband seismographs. The results were summarized as a fractal nature of source complexity and an empirical relation between the source duration T and the seismic moment Mo as Mo/T**3=1.0 e17 [Nm/s**3]. Recently I have a special concern in the real-time seismology where the information of seismic source and strong ground motion is desired to be estimated as soon as possible and utilized for disaster mitigation. Thus, I advised Yokohama City to construct high density seismograph network which was set up in 1997, and is now in operation for the purpose of a quick decision-making of rescue action. The seismic data recorded at this network are usually used to investigate the micro-zoning of strong ground motion. Publications: 菊地正幸・中村操・山田眞・伏見実・巽誉樹・吉川一光, 1948年福井地震の震源パラメーター--１倍強震計の解析, 地震2, 52, 121--128, 1999. Koketsu, K. and M. Kikuchi, Propagation of Seismic Ground Motion in the Kanto Basin, Japan, Science, 288, 1237--1239, 2000. Yagi, Y. and M. Kikuchi, Source rupture process of the Kocaeli, Turkey, earthquake of August 17, 1999, obtained by joint inversion of near-field data and teleseismic data, Geophys. Res. Lett., 27, 1969--1972, 2000. 永井理子・菊地正幸・山中佳子, 三陸沖における再来大地震の震源過程の比較研究−1968年十勝沖地震と1994年三陸はるか沖地の比較, 地震2, 54, 267--280, 2001. 菊地正幸・山中佳子・纐纈一起, 三宅島2000年噴火活動に伴う長周期地震のメカニズムとその解釈, 地震2, 110, 204--216, 2001. 橋本徹夫・菊地正幸, 地震記象から見た1946年南海地震の震源過程, 地学雑誌, 111, 118--125, 2001. Yagi, Y. and M. Kikuchi, Partitioning between seismogenic and aseismic slip as hilighted from slow slip events in Hyuganada, Japan, Geophys. Res. Lett., , 2002. 菊地正幸, リアルタイム地震学の展開, UP(東京大学出版会), 323, 1--5, 1999. Kikuchi, M., Y. Yagi, and Y. Yamanaka, Source process of the Chi-Chi, Taiwan, earthquake of September 21, 1999 inferred from teleseismic body waves, Bull. Earthq. Res. Inst., 75, 1--13, 2000. 菊地正幸, 直前・直後対応のための早期地震情報, 地質と調査, 2, 9--14, 2000. 菊地正幸, 大地震の発生予測と都市の地震防災, かんぽ資金, 268, 10--15, 2000. 菊地正幸, リアルタイム地震学, 応用力学論文集, 3, 535--540, 2000. 菊地正幸・山中佳子, 既往大地震の破壊過程=アスペリテイの同定, サイスモ, 7, 6--7, 2001. 山中佳子・菊地正幸, 東北地方のアスペリテイマップ, 東京大学地震研究所広報, 34, 2--4, 2001. 菊地正幸, 地震波形データから震源の破壊過程を探る, 月刊地球, 24, 117--125, 2002. |
