南海珠江口盆地东部海域含似海底反射沉积层纵波速度结构: 反射波旅行时反演结果

doi:10.11978/2015144

Abstract

Abstract: This paper reports the velocity structure of bottom simulating reflector (BSR) -bearing sediment layers from the reflection travel time inversion, using the data acquired in 2012 by Guangzhou marine geological survey in the eastern Pearl River Mouth Basin of the South China Sea. The results show great lateral variation in velocity, namely, there exist a relatively high velocity zone (1800~2200 m•s^-1) and a relatively low velocity zone. Combed with the Multi-channel seismic (MCS) image, we interpret the relatively high velocity zone as gas hydrate-bearing sediments, and the relatively low velocity zone as sediments with no gas hydrate or little gas hydrate. BSR is often considered as the base of gas hydrate stability zone (GHSZ), and our results suggest that gas hydrate has irregular distribution in the stability zone. The relatively low velocity zone indicates that the BSR below may not be associated with gas hydrate, only reflecting the boundary between the normal sediments above and the free gas-bearing sediments below.

Key words: gas hydrate, bottom simulating reflector, reflection travel time inversion, P wave velocity structure

LIU Bin, GENG Jianhua. Velocity structure of bottom simulating reflector-bearing sediment layers in the eastern Pearl River Mouth Basin of the South China Sea: Results from reflection travel time inversion[J].Journal of Tropical Oceanography, 2016, 35(6): 29-35.

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Velocity structure of bottom simulating reflector-bearing sediment layers in the eastern Pearl River Mouth Basin of the South China Sea: Results from reflection travel time inversion

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