Geophysical Characterization of a Sinkhole Region: A Study toward Understanding Geohazards in the Karst Geosites

The outstanding geosites in Satun UNESCO Global Geopark, Thailand are mainly karst topography. Sinkhole which is originated from the dissolution of rocks by groundwater or acidic rainwater one potential natural disasters these geosites. To gain confident among geotourism, detecting features, cavities and surficial crucial risk assessment sustainable geopark management. As a part geohazard assessment, non-invasive geophysical methods were applied for near-surface defects features. In this study, electrical resistivity tomography (ERT), seismic multichannel analysis surface waves (MASW) have been integrated to understand mechanism an existing sinkhole formation Geopark region. ERT appeared be effective approach investigate cavity development at shallow subsurface. MASW combined help constrain interpretation lithology features vicinity sinkhole. results indicated that occurrence area was probably developed forming due increased fractured limestone bedrock. This carbonate layer contact with overlying weathering shale cohesive soil layer. changing water table infiltration heavy rainfall allowed sudden vertical downward sediments into empty voids, leading hazard.