| 講演要旨(和文) | | 駿河湾沿岸域（由比沖から富士市沖と内浦湾）で浅部地下構造を広域的に把握するため海底重力調査を50点で実施した．既存の陸上および船上重力データと新規取得の海底重力データとを編集し，海陸を接続したブーゲー異常図を作成した．この結果，由比沖から富士川河口沖にかけて東西方向の低重力異常帯が分布し，その東西両端部が既知の陸域断層の南方延長に位置していることがわかった．より詳細に見ると当該の低重力異常帯は複数の低重力異常からなっており，それらの境界と善福寺断層などの断層の延長部が対応する可能性があり，今後さらなる検討が必要である． |
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| | 講演要旨(英文) | | To better understand the shallow subsurface structure of the coastal area of the Suruga Bay, an ocean bottom gravity survey was conducted from late September to early October in 2013. The measurement points were arranged at an interval of 0.5 - 2km and the total number of them amounted to 50. No unnatural local anomalies by error data are found in the survey area, showing that the accuracy of the ocean bottom gravity data is acceptable. These newly measured ocean bottom gravity data were compiled with the existing gravity data. In a Bouguer anomaly map with an assumed density of 2.3 g/cm3, a gravity low elongated in the east-west direction lies offshore from Yui to Kambara areas. Its western and eastern edges seem to correspond to the southern extensions of the Iriyama Fault and Iriyamase Fault, respectively. In the Uchiura Bay, a gravity low is also distributed implying a basement low below the shelf. |
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