HR: 1340h
AN: OS53A-0986 [Abstracts]
TI: Distribution and characteristics of deep-sea sediment waves in the northern South China Sea
AU: * Tsai, C
EM: s0642002@gmail.com
AF: Inst. of Geophysics, No.300, Jhongda Rd., Jhongli City, Taoyuan County 32001, Taiwan
(R.O.C.), Jhongli, 32001, Taiwan
AU: Hsu, S
EM: hsu@ncu.edu.tw
AF: Inst. of Geophysics, No.300, Jhongda Rd., Jhongli City, Taoyuan County 32001, Taiwan
(R.O.C.), Jhongli, 32001, Taiwan
AU: Doo, W
EM: wenbindoo@gmail.com
AF: Inst. of Geophysics, No.300, Jhongda Rd., Jhongli City, Taoyuan County 32001, Taiwan
(R.O.C.), Jhongli, 32001, Taiwan
AU: Yeh, Y
EM: yiching.yeh@gmail.com
AF: Inst. of Geophysics, No.300, Jhongda Rd., Jhongli City, Taoyuan County 32001, Taiwan
(R.O.C.), Jhongli, 32001, Taiwan
AB:
In the northern South China Sea (SCS), the deep-sea sediment waves are distributed in two zones; one is
between the lower reach of the Formosa Canyon and Penghu Canyon, the other is between the lower reach of the
Formosa Canon and LRTPB (Luzon-Ryukyu Transform Plate Boundary). The distribution of these deep-sea
sediment waves are found below 3000 m deep and the wave front is rather parallel to the bathymetric contour
lines. Base on high resolution seismic data, we suggest that these sediment waves are caused by turbidity
currents. The sediment waves have shown asymmetrical internal structures which may be induced by high gravity
flow activity. Most of these sediment waves are less than 85 m high, and most of wavelengthes are less than 6
km long. Most of slopes are less 0.8 degree. We suggest that the Formosa Canyon and Penghu Canyon are two
major sediment transportation channels. The turbidity flows downward and may overflow directly from the turning
points of these two canyons. The sediment deposits in the stoss side and erodes in the lee side. It proceedes
downslope continuously because of gravity effect. Due to the bathymetric offset across the LRTPB, the turbidity
current can not overflow to the south of this tectonic structure, which makes LRTPB a natural sediment wave dam.
DE: 3022 Marine sediments: processes and transport
DE: 3045 Seafloor morphology, geology, and geophysics
DE: 8107 Continental neotectonics (8002)
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting