地震 第2輯
Online ISSN : 1883-9029
Print ISSN : 0037-1114
ISSN-L : 0037-1114
沖縄トラフの拡大と九州地方の地殻変動
多田 堯
著者情報
ジャーナル フリー

1984 年 37 巻 3 号 p. 407-415

詳細
抄録

The repeated triangulation surveys have revealed the conspicuous N-S extentional strain field in the central Kyusyu. This strain field has been caused by the horizontal crustal movement that the triangulation stations in both the sides of the Beppu-Shimabara Graben have moved away each others to the N-S direction. The Beppu-Shimabara Graben strikes across the central Kyusyu to the E-W direction. The gravity anomaly, the seismological data and other geotectonic data support the idea that the Beppu-Shimabara Graben is a rift of the crust and the north-eastern terminal part of the Okinawa Trough which is the active back arc basin of the Ryukyu Arc and is spreading to the N-S direction. Therefore, it is concluded that the N-S extentional crustal deformation in the central Kyusyu has been caused by the rifting and the spreading of the Okinawa Trough. In other words, the Kyusyu is rifting and spreading to the N-S direction along the Beppu-Shimabara Graben. The spreading ratio is estimated to be about 15mm/a from the horizontal crustal deformation.

著者関連情報
© 社団法人日本地震学会
前の記事 次の記事
feedback
Top