SUMMARY

Characteristics of triggered earthquake activity
in the Đà River hydroelectric ladder region

Cao Đình Trọng, Nguyễn Anh Dương, Thải Anh Tuấn, Cao Đình Triều

The characteristics of the triggered earthquake activity of the Đà River ladder of hydropower plants have been carrying out in this study. The results have shown that: The reservoir triggered earthquakes occurrence in the places of strong metamorphosed rocks (gneiss, marble...), granitites and thick limestone that have been strongly broken and with the value of the Vp/Vs ratio equal to 1.63-1.67. In the case of Đà River ladder of hydropower plants, the reservoir triggered earthquakes occurrence needs the additional condition that the height of the reservoir water level is more than 100 m; The danger of the triggered earthquake occurrence must be occurring in the following places: The segment of the Mường La - Bắc Yên seismic source connected with the Sơn I La reservoir, from lowland of the Huội Quảng dam to the lowland of Son La dam. The maximum of the triggered earthquake magnitude, Mmax.kt = 5.0-5.1; The segment I from The Pa Uon bridge to the Son La dam of the Đà River seismic source has the I dangerous of triggered earthquake with the maximum of the magnitude, Mmax.kt = 5.4- I 5.7; Almost the whole of Mường Tè seismic source and a segment of the Mường Nhé I source that connected with the Lai Châu reservoir have the dangerof triggered earthquake with the maximum magnitude, Mmax.kt = 4.8-5.1.

Người biên tập: PGS. TS Nguyễn Hồng Phương.