HR: 1330h
AN: T12C-0467    [PDF]
TI: Crustal gravitational potential energy change at the convergent plate boundary near Taiwan
AU: * Lo, C
EM: lo@oc.gep.ncu.edu.tw
AF: Institute of Geophysics, National Central University, No. 300, Chung-da Rd., Chung-li City, Taoyuan, Taiwan 320, Chung-li, 32054 Taiwan
AU: Hsu, S
EM: hsu@oc.gep.ncu.edu.tw
AF: Institute of Geophysics, National Central University, No. 300, Chung-da Rd., Chung-li City, Taoyuan, Taiwan 320, Chung-li, 32054 Taiwan
AB: The Taiwan orogen has formed due to the convergence between the Philippine Sea plate and Eurasian plate. Numerous earthquakes are occurring along the active convergent plate boundary in eastern Taiwan. To the northeast, the Philippine Sea plates is subducting northwards beneath the Ryukyu Arc. To the south, the Eurasian plate is subducting eastwards beneath the Luzon Arc. The plate interaction has caused crustal deformation and produced earthquakes. The earthquakes have caused radial permanent displacement of the crust and have altered the crustal gravitational potential energy. Here we use the earthquake source mechanisms, determined by the Broadband Array in Taiwan for Seismology (BATs) from 1995 to 2003, to calculate the crustal gravitational potential energy (GPE) change and discuss their tectonic implication along the convergent plate boundary. In Ilan Plain, the westernmost Okinawa Trough, it shows a crustal GPE loss. It is related to the crustal subsidence because of the backarc extension of the Okinawa Trough. In contrast, due to the Philippine Sea plate subucting northwards beneath Eurasian Plate, the Ryukyu convergent boundary shows systematic crustal GPE gain. Near Taiwan, the crustal GPE change is gained, indicating the collisional convergence of the Luzon Arc. To the south of Taiwan, along the Luzon Arc the crustal GPE is also gain, representing the initial uplifting of the Taiwan mountain belt.
DE: 1208 Crustal movements--intraplate (8110)
DE: 1214 Geopotential theory and determination
DE: 7205 Continental crust (1242)
DE: 7218 Lithosphere and upper mantle
SC: Tectonophysics [T]
MN: 2003 Fall Meeting