2021 Fiscal Year Final Research Report
Did large-sized earthquake-induced tsunamis repeatedly strike the Pacific coast of western Hokkaido?
| Project/Area Number |
19K03986
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Review Section |
Basic Section 17030:Human geosciences-related
|
|---|
| Research Institution | Niigata University |
|---|
Principal Investigator |
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
西村 裕一 北海道大学, 理学研究院, 准教授 (20208226)
卜部 厚志 新潟大学, 災害・復興科学研究所, 教授 (20281173)
|
|---|
| Project Period (FY) |
2019-04-01 – 2022-03-31
|
| Keywords | 津波堆積物 / 北海道 / 胆振 / 津波履歴 / 17世紀津波堆積物 |
|---|
| Outline of Final Research Achievements |
In this study, the survey of tsunami deposit were conducted along the western Pacific coast of Hokkaido from FY2021 to FY1991. Whether large-sized tsunamis with an average recurrence interval of 400 years, such as recognized in the eastern part of Hokkaido, can be observed in the western Pacific coast of Hokkaido were examined. In particular, the tsunami reccurence for the past 3,000 years in the Yufutsu area of Tomakomai City and the Shiomi area of Mukawa Town was examined, where the 17th century tsunami deposits were distributed. However no tsunami traces were found in any of the sites. Therefore, it is considered that there were no large-sized tsunami events with an interval of several hundred years at least in the past 3000 years.
|
| Free Research Field |
津波・古津波科学
|
| Academic Significance and Societal Importance of the Research Achievements |
本事業の成果のうち，最も重要なことは，北海道東部太平洋岸で認められているプレート境界で繰り返し発生する様な規模の大きな地震津波は，北海道西部太平洋岸奥部の胆振地域では少なくとも過去3000年間では17世紀津波のみであるということを明確に把握することができたことである。平均400年の再来間隔を持つ道東地域の繰り返し性を持つような地震像では，北海道西部太平洋岸の津波像を説明できないため，新たな形成モデルが必要であることも分かった．また，17世紀津波堆積物の実像解明の調査においては，X線CT画像を用いることによって津波堆積物把握精度を向上させることができることが分かったことも重要な成果であった。
|
