報告書番号

N07036

タイトル（和文）

韓国沿岸における津波に関する研究～日本海と東シナ海を対象にした地震と津波に関する文献調査と津波数値計算～

タイトル（英文）

Study on Tsunami due to Offshore Earthquakes for Korea Coast -Literature Survey and Numerical Simulation on Earthquake and Tsunami in the Japan Sea and the East China Sea-

概要 （図表や脚注は「報告書全文」に掲載しております）

原子力発電所のある韓国沿岸における津波に関して検討した．まず，日本海における歴史地震と歴史津波に関して，データベースを作成し，日本海の津波の津波の80%以上が日本海東縁部で発生したものであることを明らかにした．韓国沿岸において，歴史津波では1983年日本海中部地震津波による被害が最も大きく，その最大津波高さは約4mである．また，琉球諸島付近に位置するフィリピンプレートとユラーシアプレートの境界で起こる断層モデルを想定し，津波計算を実施したところ，津波の高さは0.25m以下となった．
以上のことから，韓国沿岸において最も懸念される津波は，日本海東縁部や北海道西方沖で発生する津波である．1983年日本海中部地震津波では，水位上昇は最大4m程度であったが，その高さに対して韓国の原子力発電所の敷地高に余裕は認められる．ただし，日本海東縁部や北海道西方沖で既往最大以上の津波が発生する可能性は否定できない．

概要 （英文）

In Korea, there has been a concern on tsunami risks for the Nuclear Power Plants since the 1983 Nihonkai-Chubu earthquake tsunami. The maximum run-up height reached 4 m to north of the Ulchin nuclear power plant site. The east coast of Korea was also attacked by a few meters high tsunami generated by the 1993 Hokkaido Nansei-Oki earthquake. Both source areas of them were in the areas western off Hokkaido to the eastern margin of the Japan Sea, which remains another tsunami potential. Therefore it is necessary to study tsunami risks for coast of Korea by means of geological investigation and numerical simulation.
Historical records of earthquake and tsunami in the Japan Sea were re-compiled to evaluate tsunami potential. A database of marine active faults in the Japan Sea was compiled to decide a regional potential of tsunami. Many developed reverse faults are found in the areas western off Hokkaido to the eastern margin of the Japan Sea. The authors have found no historical earthquake in the East China Sea which caused tsunami observed at coast of Korea. Therefore five fault models were determined on the basis of the analysis results of historical records and recent research results of fault parameter and tsunami. Tsunami heights were estimated by numerical simulation of nonlinear dispersion wave theory. The results of the simulations indicate that the tsunami heights in these cases are less than 0.25m along the coast of Korea, and the tsunami risk by these assumed faults does not lead to severe impact. It is concluded that tsunami occurred in the areas western off Hokkaido to the eastern margin of the Japan Sea leads the most significant impact to Korea consequently.

報告者

キーワード