ภาพตัดขวางคลื่นไหวสะเทือนของแอ่งหาดใหญ่

Abstract

Hat Yai Basin is a Quaternary sediment basin in the southern part of Songkhla lake basin. The geological structure is thought to be graben and horst structure. Understanding subsurface of this area is important because it is located in the economic zone. Seismic reflection and multichannel analysis of surface wave (MASW) method were conducted nearby the boundary of the Hat Yai basin to characterize the subsurface geological structure and to determine the depth to bedrock. Two survey lines, locating in the east and west of the basin, were investigated nearby the boundary of the Hat Yai Basin with a total length of 5.3 kilometers. The study shows that the seismic sections, seismic tomography and V sections could assist in the delineation of subsurface at about 150 m depth. The thickness of Quaternary sedimentary layers of the first survey and the second survey line is about 50 m and 70 m, respectively. The depth of bedrock is approximately more than 100 m. The appearance of seismic discontinuities in seismic section is interpreted to be paleochannel in the shallow subsurface of Quaternary sediment. This study can develop more details of the hydrogeological structure.