FN Archimer Export Format
PT J
TI Thermal modeling of the SW Ryukyu forearc (Taiwan): Implications for the seismogenic zone and the age of the subducting Philippine Sea Plate (Huatung Basin)
BT 
AF GUTSCHER, M. -A.
   KLINGELHOEFER, Frauke
   THEUNISSEN, T.
   SPAKMAN, W.
   BERTHET, T.
   WANG, T. K.
   LEE, C. -S.
AS 1:1;2:2;3:3;4:4,5;5:6;6:7;7:7;
FF 1:;2:PDG-REM-GM-LAD;3:;4:;5:;6:;7:;
C1 Univ Brest CNRS, CNRS, IUEM, Lab Domaines Ocean, Rue Dumont Durville, F-29280 Plouzane, France.
   IFREMER, Dept Marine Geosci, Brest, France.
   Univ Bergen, Dept Earth Sci, N-5020 Bergen, Norway.
   Univ Utrecht, Dept Earth Sci, Utrecht, Netherlands.
   Univ Oslo, Ctr Earth Evolut & Dynam, N-0316 Oslo, Norway.
   Uppsala Univ, Dept Earth Sci, Uppsala, Sweden.
   Natl Taiwan Ocean Univ, Dept Geophys, Taipei, Taiwan.
C2 UBO, FRANCE
   IFREMER, FRANCE
   UNIV BERGEN, NORWAY
   UNIV UTRECHT, NETHERLANDS
   UNIV OSLO, NORWAY
   UNIV UPPSALA, SWEDEN
   UNIV NATL TAIWAN OCEAN NTOU, TAIWAN
SI BREST
SE PDG-REM-GM-LAD
UM LGO
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-europe
   copubli-univ-france
   copubli-int-hors-europe
IF 2.693
TC 12
UR https://archimer.ifremer.fr/doc/00324/43522/43054.pdf
LA English
DT Article
DE ;Subduction;Finite-element modeling;Forearc thermal structure;Seismogenic zone
AB Subduction mega-thrust earthquakes in the SW Ryukyu trench pose a seismic and tsunami hazard. One of the objectives of this study is to estimate the downdip width of the seismogenic zone using numerical modeling to determine the temperature distribution along the plate interface. However, this approach depends strongly on the thermal parameters of the subducting slab. While the Philippine Sea plate (PSP) subducting beneath the central and eastern Ryukyu arc is of Eocene age (35–50 Ma), its age west of the Gagua Ridge is uncertain, with proposed ages ranging from Lower Cretaceous (140 Ma) to Upper Eocene (35 Ma). Since the sparse available heat flow data are insufficient to resolve this debate, both end-member hypotheses are tested as input parameters. We examined two transects at 122.5°E and 123.5°E on either side of the N-S trending, 4-km high, Gagua Ridge. The shallow forearc geometry is obtained from wide-angle seismic data. The deep slab geometry was obtained from hypocenter distribution and tomography. For an Eocene slab age, we obtain a 100 km and 110 km wide seismogenic zone (between the 150 °C and 350 °C isotherms) west and east of Gagua Ridge, respectively. This is in good agreement with the observed distribution of hypocenters. Using a Cretaceous slab west of Gagua Ridge predicts a deep seismogenic zone (25 km–60 km depth), inconsistent with observed thrust earthquakes. Tomographic images at 122.5°E and 123.5°E show a similar slab thickness of 70–80 km suggesting that the oceanic lithosphere has a young (Eocene) thermal age. The westernmost PSP (Huatung Basin) may have been thermally rejuvenated by mantle convection near the slab corner. The tectonic history since 6 Ma (transition from subduction to collision beneath Taiwan) may have also perturbed the thermal structure.
PY 2016
PD DEC
SO Tectonophysics
SN 0040-1951
PU Elsevier Science Bv
VL 692
IS Part.B
UT 000390823700004
BP 131
EP 142
DI 10.1016/j.tecto.2016.03.029
ID 43522
ER

EF