Abstract
The Mid-Niigata Prefecture earthquake in 2004 (MJMA 6.8) generated surface ruptures along the eastern rim of the Uonuma Hills. To elucidate the structural linkage between the surface ruptures and the source fault at depth, the high-resolution seismic reflection profile across the surface ruptures and nearby active faults, and the data of aftershock distribution are examined. The 5.2-km-long, high-resolution, depth-converted seismic section reveals an emergent thrust beneath the surface ruptures. A two-dimensional model of the fault geometry has been constructed based on the aftershock distribution and the shallow reflection profile. The development of the main geologic structure are well explained by forward modeling using a balanced cross-section method. In detail, the fault system generated the main shock dips at a steep angle (60°) below 5 km depth and more shallowly (30°) near the surface.
Original language | English |
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Pages (from-to) | 447-452 |
Number of pages | 6 |
Journal | earth, planets and space |
Volume | 57 |
Issue number | 5 |
DOIs | |
Publication status | Published - 2005 |
Externally published | Yes |
Keywords
- 2004 Mid-Niigata Prefecture earthquake
- Active fault-and-fold
- Balanced-cross section
- Central Japan
- Fault model
- Seismic reflection profile
- Subsurface structure
- Surface rupture
ASJC Scopus subject areas
- Geology
- Space and Planetary Science