1999 Fiscal Year Final Research Report Summary
Earthquake Disaster Evaluation Based on Estimation of Deep Underground Structure and Observation of Strong Ground Motion in Deep Sedimentary Basins
| Project/Area Number |
10480090
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Natural disaster science
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
SASATANI Tsutomu Hokkaido Univ., Grad. School of Sci., Asso. Pro., 大学院・理学研究科, 助教授 (10002148)
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| Co-Investigator(Kenkyū-buntansha) |
KASAHARA Minoru Hokkaido Univ., Grad. School of Sci., Pro., 大学院・理学研究科, 教授 (40001846)
WATANABE Teruo Hokkaido Univ., Grad. School of Sci., Pro., 大学院・理学研究科, 教授 (40135900)
OKADA Hiroshi Hokkaido Univ., Grad. School of Sci., Emeritus, 物理探査技術顧問
KAGAMI Hiroshi Hokkaido Univ., Grad. School of Eng.., Pro., 大学院・工学研究科, 教授 (70016476)
OSHIMA Hiromitsu Hokkaido Univ., Grad. School of Sci., Inst., 大学院・理学研究科, 助手 (10213703)
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| Project Period (FY) |
1998 – 1999
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| Keywords | deep sedimentary basin / Sapporo urban region / deep underground structure / microtremore exploration method / strong motion observation / site amplification / spatial variation of seismic response / seismic intensity |
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| Research Abstract |
Our target area is Sapporo urban region with almost 2 millions population, that is located on a deep sedimentary basin. We have conducted research there on the following five heads: 1) geological environment, 2) seismological environment, 3) deep underground structure, 4) strong motion observation, and 5) evaluation of earthquake disaster.
Our research results are:
・ We have obtained a few deep-boring data to a depth of about 4000 m. The geological structure shows that the deepest core has a geological time of Miocene (Tertiary).
・ We have obtained PS logging data to a depth of about 500 m at several sites. They show spatial variation of P- and S- wave velocity structures.
・ We have estimated deep underground structures at several sites by the microtremor exploration method. The basement has S-wave velocity of about 3000 m/s.
・ We have carried out a strong motion observation at 15 sites. The data show spatial variation of the seismic response and strong excitation of basin surface waves.
・ We have examined the effects of underground structures on seismic motion based on obtained strong motion data. The examination shows an importance of deep underground structures in evaluation of site amplification.
・ We have found some relationships between seismic intensity distribution and underground structure.
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