Abstract

In this paper, the authors present some new interpretations of the mantle P wave velocity model and the linkage to the modern geodynamics of the South East Asia (SEA) lithosphere. The obtained results have shown that:

1/ The subduction zones surrounding SEA is characterized by the “columnar” P wave model in the upper mantle, transitional layer and in the layer 1.  The earthquakes occurred along this zones demonstrate higher frequency and stronger magnitude than ones occurred in the intra-plate region.   

2/ The Hải Nam - Natuna intra-plate Fault Zone subdivides the mantle of SEA into two parts: The eastern part demonstrates clear horizontalP wave velocity variation while the estern part is characterized by vertical and horizontal P wave velocity change.

3/ The formation of “mantle flows” from outside into the inside of SEA has triggered  the strong variation of the intra-plate mantle in SEA.