報告書番号

U00019

タイトル（和文）

平成12年鳥取県西部地震調査速報

タイトル（英文）

Reconnaissance Report on the Western Tottori prefecture earthquake in 2000

概要 （図表や脚注は「報告書全文」に掲載しております）

平成12年（2000年）10月6日13時30分頃に，鳥取県西部の内陸部を震源とする気象庁マグニチュード7.3の地震が発生し，鳥取県内で最大震度6強を記録したほか，中国，四国地方の広い範囲で震度5以上を記録した．本報告は，この地震について，これまで実施した，地表踏査，臨時余震観測，構造物被害調査などの資料を速報記録としてとりまとめたものである．内陸型のマグニチュード7級の地震規模であったにもかかわらず，地表地震断層が明確に確認されていないこと，被害が過去の同規模の地震と比べて小さかったこと，などが特徴である．震源近傍では，地表で最大927Galが記録された（科技庁）ほか，コンクリートダムで最大2051Galが記録された．電力関係では，地震に伴う停電が約２時間で復旧されたが，震源近傍の水力発電設備，送電設備，変電設備に被害があり，それらの原因究明と対策が急務となっている．

概要 （英文）

An earthquake with a magnitude of 7.3 (Mj) occurred on 6 October 2000 in the western Tottori prefecture of Japan. This earthquake is officially called the Western Tottori prefecture earthquake in 2000. The earthquake recorded the maximum seismic intensity of 6-strong on the JMA scale in Tottori prefecture and 5 in a wide area of Chugoku and Shikoku regions. This report summarizes the results of the quick investigations conducted by the CRIEPI’s reconnaissance teams on the fault trace, aftershock observations and damage investigations. Although the large magnitude of over 7 occurred at inland, it should be noted that surface fault raptures are not clearly found yet, and the damages of the infrastructures are not so significant comparing with the similar past earthquakes. As for earthquake motions, it is reported that the peak ground motion is 927Gal at the ground surface, and 2051Gal at the top of a concrete dam. Power supply was recovered within 2 hours after the earthquake though there were some physical damages to hydropower facilities, transmission facilities and substation facilities. At present, the information and the data about the damaged and/or undamaged structures, and geological and ground conditions are not enough collected. More detailed investigations are essential to fully learn the lessons from this earthquake disater and apply those for the earthquake hazard mitigation in the future.

報告者

キーワード