SUMARY

The distribution characteristics of shallow gas in Quaternary sediments in Thửa Thiên Huế - Bình Định

coastal areas and their influence to engineering geology

Lê Anh Thắng, Nguyễn Hữu Hiệu, Ngô Thanh Thủy. Nguyền Quốc Huy,

Nguyễn Vãn Thắng, Nguyễn Trọng Phương, Nguyễn Thị Thùy Dung

The results of the Project "Investigation of geological charateristics. geodynamics, mineral geology, environmental geology and geohazard prediction in Thừa Thiên Huế- Bình Định coastal areas from 0 m to 60 m water depth, ratio 1: 100.000" has identified some gas seepage zones and the expression of shallow gas. The shallow gas pockets distributed in Quaternary sediments, the depth of distribution is not great below the seabed, they relate to the old swamp formations and directly affect to engineering geology conditions in the study area; The shallow gas presence was discovered by the interpretation of high resolution shallow seismic data. It is linked to the zones of acoustic blank, acoustic lurbidity, gas seepage and dome reflection of seismic waves on the sea floor. Within the research area, seismic reflection configurations are characterized by: White reflections, in which the upper formations demonstrate clear reflections while the lower part shows chaotic configurations of the seismic reflection; Mixed seismic reflections are characterized by a localized continuous variation in seismic reflection configuration (Due to enhanced reflections). Dome-shape reflection is characterized by dome-shape and emerging above high resolution shallow seismic data of section.

Người biên tập: TS. Nguyễn Thế Hùng.