岡山大学 地球科学研究報告
Published by Okayama University Earth Science Reports Editorial Committee

Topography of the Moho discontinuity estimated by column inversion of gravity anomaly data

福永 真理子 Department of Earth Sciences, Okayama University
小田 仁 Department of Earth Sciences, Okayama University
志知 竜一 Faculty of Engineering, Chubu University
抄録
We present an inversion method, called "column inversion", to retrieve two-dimensional variation of the depth to the Moho discontinuity from Bouguer gravity anomaly data, assuming that a density jump between the lower crust and upper mantle is regionally invariant. The inversion method is applied to reveal the apatial undulation of the Moho discontinuity in the Chugoku and Shikoku districts, southwest Japan. The result shows that the Moho is deep in the land area and shallow in the sea area. The Moho is anomalously deep in the west regions of Shikoku and Chugoku districts, where the prominent negative gravity anomaly is observed. The two-dimensional variation of the Moho depth is quite similar to that determined by inversion of the first P-arrival time data. The column inversion of the Bouguer gravity anomaly data is proved to be useful for determining the fine structure of the Moho discontinuity undulation.
キーワード
Bouguer Gravity Anomaly
Column Inversion
Moho Discontinuity
Chugoku and Shikoku Districts
ISSN
1340-7414
NCID
AN10506284
NAID