最上トラフ酒田海丘(仮称)における海底下構造・比抵抗構造から見る表層型メタンハイドレートの賦存状況

Abstract

A knoll in the Mogami Trough on the eastern margin of the Sea of Japan, called the Sakata Knoll, is known as a shallow methane hydrate (MH) field. There are still many unknowns regarding the distribution of the shallow MH. We try an integrated analysis using subseafloor geological and resistivity structures for understanding more accurate distribution of the shallow MH. We chose one of the seismic attribute analysis results “the acoustic blanking zone” as an initial model for the resistivity inversion. The result of the resistivity inversion shows a large anisotropy, strongly suggesting an anisotropic occurrence of the shallow MH. It is also suggested that the lower boundary of MH coincide with the depth of BSR. To promote integrated analysis using different data sets with different scopes and resolutions, we continue to develop more effective methods for the future.