Determination of Landslide Area using Geoelectrical Resistivity by Dipole-Dipole Method due to the Cianjur Earthquake, Indonesia

Landslides are complex geological occurrences with socio-economic impacts, causing significant loss of life and physical catastrophe. Most landslides are triggered by heavy rainfall, earthquakes, or combinations. Therefore, it is necessary to study behavior to identify indicators related to landslides. This study will evaluate the geometry and depth of the crucial slip surface zone in the Cianjur earthquake on November 21, 2022 to understand landslide factors. The geoelectric dipole-dipole approach predicts geological layer slip surfaces. This method was chosen to interpret surface visualization and rapid data acquisition by varying electrical resistivity utilizing a pair of current and potential electrodes for rapid and specific geological profile surveys. This study examined six landslide cross-sections. Four sections were studied at 60 meters deep, and two at 30 meters. The investigation showed that the landslide type was rotational and dominated by tuff, with resistivity values ranging from 12 to 60 ohmmeters. The critical slip surface was found in the tuff layer and lava below it, which had higher resistivity than 60 Ohmmeters, a 40-meter slip surface, and a 3200 square-meter landslide area in the middle. Based on this study, the determination of slip surface using geoelectric with the dipole-dipole method can help analyze the landslide area.