Summary

The characteristics of Seismic activity in the South Central Region

Cao Đình Trọng, Mai Xuân Bách, Phạm Nam Hưng, Thái Anh Tuấn; Lê Văn Dũng; Đình Quốc Văn, Cao Đình Triều

This paper presents the content of research on: the feature of seismic activity, the seismic source and the maximum earthquake (Mmax) in the South Central Region. Research results show that: The seismic activity is characterized by the following quantities: b = 0.67; a = 1.91, Mmin = 2.6, the thickness of seismic layer (seismogenic layer) of about 16 km (from 2km depth to 18km depth). The seismic sources (seismogenic zones) with M≥5.0 include: 1) Tanh Linh; 2) Thuan Hai - Minh Hai; 3) Northern Cuu Long; 4) Cuu Long; 5) Southern Cuu Long; 6) Eastern Phu Quy; 7) Canh Duong; and 8) Saigon River. The maximum earthquake (Mmax) by several different methods obtains the following results: a) On the basic of Neural Network method, Mmax=5.5; b) According to the modified Gumbel Type-I distribution, Mmax = 5.472; c) According to the distribution of frequency - magnitude relationship, Mmax = 5.9. The earthquake with the maximum magnitude is likely to occur at Thuan Hai - Minh Hai fault (Mmax = 6.0). The Mmax values at the remaining faults vary between 5.0 ÷ 5.5. 

Keywords: seismic sources, seismic activity, maximum earthquake, South Central Region.