SUMMARY

Seismic danger in West Bắc Bộ and adjacent areas

Cao Đình Triều, Lê Văn Dũng, Thái Anh Tuấn

In this paper, the authors presente some results of seismic hazard assessment in West Bắc Bộ and adjacent areas on the basis of the neodeterministic algorithm. The following conclusions can be made:

1. The maximum magnitude of earthquake occurrences in the West Bắc Bộ and adjacent areas can reach the average values of: Mmax = 6.5-7.0 in Sông Mã and Sơn La - Sông Đà zones; Mmax = 5.0-5.5 in Sông Hồng; Mmax = 5.5-6.0 in Mường Tè; Mmax = 5.5-6.0 in Lai Châu - Điện Biên and Mmax = 6.0-6.5 in Sông Cả zones.

2. The maximum average value of horizontal displacement component (Dmax) of more than 18 cm covers the whole territory of Sơn La Province, while in Ninh Bình and Hà Nam Provinces it is 16 cm. The velocity (Vmax) is 11 cm/s in Sơn La Province, from 6.0 to 11 cm/s in the east of Điện Biên, Ninh Bình, Hà Nam Provinces and the centre of Lai Châu Province.

3. The maximum average values of A, DGA (using EC8 for A, B, C class of bedrock) can reach: A> 0.2 g; DGA (using EC8 for A class of bed rock) > 0.3 g; DGA (using EC8 for B class of bed rock) > 0.2 g; and DGA (using EC8 for C class of bed rock) > 0.15 g.

Người biên tập: Nguyễn Hồng Phương