Subsurface structures of solution dolines inferred from electrical resistivity tomography: A hypothesis on the evolutionary process of solution dolines at the Akiyoshi-dai Plateau, southwest Japan

The evolution of solution dolines is regulated by carbonate dissolution mediated by water and CO2. The subsurface structure influences the evolutionary pattern of the dolines. Despite the significant effects of enlarged joints or shafts on the development of solution dolines, a few studies have identified the subsurface structures of multiple solution dolines. To this end, we utilized 2-D electrical resistivity tomography (ERT) at 15 dolines and an outcrop in the Akiyoshi-dai Plateau, Japan, which is composed of massive and fractured limestone lithology. The results of ERT exhibited the following: (i) a similar range for electrical resistivity in parallel to the topographic relief; (ii) an increase in resistivity with depth, and; (iii) a low resistivity zone characterized by