关键词: 地震地质, 活动断层, 现代构造应力场, 深部构造, 南黄海

Abstract: Jiangsu Province and the adjacent Southern Yellow Sea area is one of the most economically developed regions in east
China, along with dense cities, large population and integrative infrastructures. This area is, unfortunately, vulnerable to earthquake
hazard threatening its socio-economic development. Historically a number of medium and strong magnitude earthquakes frequently
occur this area. The seismogenic mechanism for this area is not well understood. Here we collect all the historical and instrumental
earthquake data available in this area, to investigate the spatiotemporal pattern of the seismicity and its seismotectonics. We found that
the earthquakes are clustered and generally associated with several main active fault zones; the seismically quiescent period for this
area approximates to 60 years, and it is now still at the active phase. In addition, integrative geophysical analysis demonstrates that the
Wunansha Uplift and Southern Depression of the Jiangsu and Southern Yellow Sea areas, where the seismicity is comparatively
intensive, show prominent deep structure anomalies, suggesting a genetic link between the seismicity and deep structure. The westward
subduction of the Philippian Sea Plate and the far field effect of the Indo-Asia continental collision, along with the gravity potential
difference derived from the elevation contrast between the craton and shelf area, account for the driving force trigging the earthquake.
The results presented here not only promote our understanding of seismotectonics in this region but also have important significance for
earthquake hazard mitigation in the Jiangsu and Southern Yellow Sea area.

Key words: seismotectonics, active fault, tectonic stress field, deep structure, Southern Yellow Sea