Seismic shear wave imaging reveals the characteristics of magmatic activity and crustal extension in the northeastern part of the South China Sea

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The continental margin of the northeastern South China Sea is a unique continental margin, which has the characteristics of weak magmatism in the early stage of tension fracture and strong magmatism in the later stage of fracture.

The researchers collected the OBS data ( NS5 survey line) collected in the Dongsha waters , and used the inversion method to obtain the structure model of the P wave, S wave and Vp/Vs data

Studies have shown that the degree of crustal extension and thinning in the ocean - continent transition zone in the northeastern South China Sea is intense, forming a large number of extensional faults.

This research has been introduced by the Southern Ocean Science and Engineering Guangdong Laboratory (Guangzhou) talent team to introduce a major special project ( GML2019ZD0204 ), a National Natural Science Foundation project ( 42076071, U1701641, 41906055 ), Guangdong Provincial Science and Technology Plan Project Guangdong Province Earthquake Prevention and Disaster Mitigation Science and Technology Collaboration Joint funding from the Innovation Center ( 2018B020207011 ) and the Guangdong Provincial Key Project ( 2019BT02H594 )

Related paper information: https://doi.

Figure 1Tomo2D inversion model; ( a ) P- wave velocity structure model; ( b ) S- wave velocity structure model; ( c ) Vp/Vs model 

Figure 2Vp and Vp/Vs cast point diagram to judge lithology (corrected to 600 MPa and room temperature)

Figure 3( a ) Vp/Vs model, the dark red area indicates Vp/Vs> 1.