Abstract
The shallow subsurface is subject to various human activities, and the place of occurrence of geohazards, e.g. shallow active faults. The identification of the location and orientation of such faults can be vital for infrastructure development. The aim of this study was to develop a low-cost 3D resistivity survey system, with reasonable survey time for shallow fault investigations. The study area in Songkhla Province, Thailand is located in an old quarry where faults could be identified in outcrops. The study area was designed to cover the expected fault with 100 electrodes arranged in a 10×10 square grid with an electrode spacing of 3 meters in x and y axis. Each electrode in turn was used as a current and potential electrode using a dipole-dipole array. Field data have been processed and interpreted using 3DResINV. Results, presented in horizontal depth slices and vertical xz- and yz-cross sections, revealed through differences in resistivity down to 8 m depths a complex structural setting with two shallow faults and dipping sedimentary rock layers. In conclusion, this study has shown that a 3D resistivity survey can imagine complex tectonic structures, thus providing a far more insight into the shallow subsurface.
Highlights
The shallow subsurface, the first few hundred meters below the Earth’s surface, is subject to various human activities, e.g., building foundations, groundwater drilling, and the place of occurrence of potential geohazards, e.g., landslides and shallow active faults
The identification of the location and orientation of shallow faults can be vital for infrastructure development, mitigating the impact of potential earthquakes
In order to get more information about a more complex subsurface either several 2D surveys have to be conducted or real 3D ones. Among the latter ones is the 3D resistivity method. It is a relatively fast and easy method to do in comparison to a real 3D seismic reflection survey, which is commonly applied in petroleum exploration and deeper depths
Summary
The shallow subsurface, the first few hundred meters below the Earth’s surface, is subject to various human activities, e.g., building foundations, groundwater drilling, and the place of occurrence of potential geohazards, e.g., landslides and shallow active faults. The identification of the location and orientation of shallow faults can be vital for infrastructure development, mitigating the impact of potential earthquakes. Various types of geophysical methods can be used to identify and locate faults in the shallow subsurface, e.g. 2D resistivity, seismic reflection, and ground penetrating radar; these techniques produce only a 2D cross section of the subsurface. In order to get more information about a more complex subsurface either several 2D surveys have to be conducted or real 3D ones. Among the latter ones is the 3D resistivity method. It is a relatively fast and easy method to do in comparison to a real 3D seismic reflection survey, which is commonly applied in petroleum exploration and deeper depths
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
