| Project/Area Number |
08680191
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
自然地理学
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| Research Institution | TSURUOKA NATIONAL COLLEGE OF TECHNOLOGY |
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Principal Investigator |
SAWA Hiroshi TSURUOKA NATIONAL COLLEGE OF THECNOLOGY,GENERAL EDUCATION,LECTURER, 一般科目, 講師 (80241222)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1997: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1996: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | active fault / seimic risk assesment / Holocene surface faulting / flexural scarp / reverse fault / interpretation of large-scale air photographs / morphological analysis / 断層変位地形 |
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| Research Abstract |
Holocene surface faultings are newly recognized in the eastern boundary faults of the Shonai Plain, the western boundary faults of the Yamagata Basin and the eastern boundary faults of the Kamishiro Basin along the Northem part of Itoigawa-Shizuoka Tectonic Line, based on the interpretation of large-scale air photographs and the field survey. Holocene and late Pleistocene deformation is demonstrated along theses faults, and the degree of faults activity, based on vertical displacement, is class A to B (slip rate ; 0.1-1.5m/ka).
Holocen flexural scarps of one to two meters or less in relative height is characteristic deformed feature along these faults, implying that this is resulted from low angle reverse faulting.
Holocene flexural scarps are situated one hundred meters to one kilometer off from the piedmont line, which indicates that Holocene reverse faulting migrates to the basin. The fold systems well develop in the study areas, which shows that the folding is related to the late Quaternary faulting in the unconsolidated basin deposits.
In conclusion, (1) active reverse faults are associated with Holocene flexural scaps which have very gentle slope, (2) the interpretation of large-scale air photographs is helpful to the recognition of active reverse faults which have high seismic risk.
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