Phase transformation and study of earthquakes formation mechanism of Manila trench
Chen Aihua1, Xu Hehua2
1. Key Laboratory of Marine Mineral Resources, Ministry of Land and Resources, Guangzhou Marine Geology Survey, Guangzhou 510075;
2. Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301
According to geophysical data of Manila subduction zone, we select three typical cross-sections to simulate the thermal structure, analyze the phase transformation, and study the earthquakes formation mechanism. The results show that: 1)Oceanic crust of B—B' cross-section enter eclogite at about 95 km depth while C—C' cross-section at 160 km depth,2)Earthquake in the middle of Manila subduction zone is tend to occur above 100 km depth, but the south is more deeper,3)Manila subduction plate have been torn off, under where is not prone to cause seismic activity, which impact deep source earthquake.