Abstract
The Median Tectonic Line (MTL) is the longest arc-parallel fault system in southwest Japan whose right-lateral strike-slip is related to oblique subduction of the Philippine Sea plate (PH). We constructed a dense Global Positioning System network along a 200 km-long traverse line across the MTL in 1998 to estimate deep fault structure and slip distribution. Horizontal velocities were determined at 65 sites through campaign measurements and show crustal shortening in the direction of the plate convergence. Using multi-rectangular segments and depth-dependent coupling at the plate interface, we calculate and remove elastic deformation caused by the PH subduction. The residual velocity field shows right-lateral strike-slip block motion of about 5 mm/yr across the MTL, consistent with geological estimates. However, the block boundary does not coincide with the surface trace of the MTL, being displaced 20-30 km to the north. The residual velocity field is reproduced by a model with a 35-45° northwarddipping fault plane, full locking of the upper portion to a depth of 15 km, and steady slip of 5 mm/yr below. GPS results are supported by imaging of an inclined fault plane revealed by seismic profiling and currently low activity of shallow earthquakes.
| Original language | English |
|---|---|
| Pages (from-to) | 1065-1070 |
| Number of pages | 6 |
| Journal | earth, planets and space |
| Volume | 54 |
| Issue number | 11 |
| DOIs | |
| Publication status | Published - Jan 1 2002 |
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All Science Journal Classification (ASJC) codes
- Geology
- Space and Planetary Science
Cite this
Subsurface structure and faulting of the Median Tectonic Line, southwest Japan inferred from GPS velocity field. / Tabei, Takao; Hashimoto, Manabu; Miyazaki, Shin'ichi; Hirahara, Kazuro; Kimata, Fumiaki; Matsushima, Takeshi; Tanaka, Torao; Eguchi, Yasuhide; Takaya, Takashi; Hoso, Yoshinobu; Ohya, Fumio; Kato, Teruyuki.
In: earth, planets and space, Vol. 54, No. 11, 01.01.2002, p. 1065-1070.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Subsurface structure and faulting of the Median Tectonic Line, southwest Japan inferred from GPS velocity field
AU - Tabei, Takao
AU - Hashimoto, Manabu
AU - Miyazaki, Shin'ichi
AU - Hirahara, Kazuro
AU - Kimata, Fumiaki
AU - Matsushima, Takeshi
AU - Tanaka, Torao
AU - Eguchi, Yasuhide
AU - Takaya, Takashi
AU - Hoso, Yoshinobu
AU - Ohya, Fumio
AU - Kato, Teruyuki
PY - 2002/1/1
Y1 - 2002/1/1
N2 - The Median Tectonic Line (MTL) is the longest arc-parallel fault system in southwest Japan whose right-lateral strike-slip is related to oblique subduction of the Philippine Sea plate (PH). We constructed a dense Global Positioning System network along a 200 km-long traverse line across the MTL in 1998 to estimate deep fault structure and slip distribution. Horizontal velocities were determined at 65 sites through campaign measurements and show crustal shortening in the direction of the plate convergence. Using multi-rectangular segments and depth-dependent coupling at the plate interface, we calculate and remove elastic deformation caused by the PH subduction. The residual velocity field shows right-lateral strike-slip block motion of about 5 mm/yr across the MTL, consistent with geological estimates. However, the block boundary does not coincide with the surface trace of the MTL, being displaced 20-30 km to the north. The residual velocity field is reproduced by a model with a 35-45° northwarddipping fault plane, full locking of the upper portion to a depth of 15 km, and steady slip of 5 mm/yr below. GPS results are supported by imaging of an inclined fault plane revealed by seismic profiling and currently low activity of shallow earthquakes.
AB - The Median Tectonic Line (MTL) is the longest arc-parallel fault system in southwest Japan whose right-lateral strike-slip is related to oblique subduction of the Philippine Sea plate (PH). We constructed a dense Global Positioning System network along a 200 km-long traverse line across the MTL in 1998 to estimate deep fault structure and slip distribution. Horizontal velocities were determined at 65 sites through campaign measurements and show crustal shortening in the direction of the plate convergence. Using multi-rectangular segments and depth-dependent coupling at the plate interface, we calculate and remove elastic deformation caused by the PH subduction. The residual velocity field shows right-lateral strike-slip block motion of about 5 mm/yr across the MTL, consistent with geological estimates. However, the block boundary does not coincide with the surface trace of the MTL, being displaced 20-30 km to the north. The residual velocity field is reproduced by a model with a 35-45° northwarddipping fault plane, full locking of the upper portion to a depth of 15 km, and steady slip of 5 mm/yr below. GPS results are supported by imaging of an inclined fault plane revealed by seismic profiling and currently low activity of shallow earthquakes.
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U2 - 10.1186/BF03353303
DO - 10.1186/BF03353303
M3 - Article
AN - SCOPUS:0037952264
VL - 54
SP - 1065
EP - 1070
JO - Earth, Planets and Space
JF - Earth, Planets and Space
SN - 1343-8832
IS - 11
ER -