SUMMARY

Recent geodynamic characteristics of Vietnamese coastal zones

Cao Đình Triều, Lê Duy Bách, Ngô Gia Thắng, Bùi Anh Nam, Trần Nghi,
Chu Văn Ngợi, Nguyễn Văn Vượng, Phạm Huy Long, Đỗ Văn Lĩnh, Nguyễn Tài Thinh

In this article, the authors attempt to present the principles of establishment of recent geodynamic map for Vietnamese coastal zones. The obtained results show that:

1/ The Earth’s crust in the Vietnamese coastal zones is in the equilibre and compressed state. The compression has the N-NE (5-100) direction gradually changing to longitudinal direction from Móng Cái to Nghệ-Tĩnh areas; N-NW direction to sublatitudinal direction from Quảng Bình to Đà Nẵng areas; sublatitudinal to latitudinal from Quảng Ngãi to Phú Yên areas and; from N-NW (20-300) to S-SE in coastal zone of South Trung Bộ, Nam Bộ and Kiên Giang - Cà Mau areas.

2/ Strongest earthquake can occur in the Vietnamese coastal zone with maximal magnitude of  6.5-7.5 Richter degree, and with Mmax = 7.0-7.5 in almost all source areas of the studied region. In the Ba Tơ - Cng Sơn, Biên Hòa - Tuy Hòa, East Côn Sơn, Phú Quý - Cảnh Dương, Hòn Chuối and Cà Mau source areas, earthquake may occur with Mmax of about 6.5-7.0 Richter degree. The Nha Trang source area has the earthquake danger with Mmax not surpassing 6.5.

3/ In recent time, endogenous dynamic activities continue to occur with various scales, such as manifestations of heat flows, volcanic activities and tectonic movements. They have the tendency of concentrating in basic tectono-geodynamic boundaries of the region.

Người biên tập: TS. Phùng n Phách.