Application of Very Low Frequency (VLF) Method for Underground River Estimation in Donorojo Sub-District, Pacitan
Year: 2024
Type: article
Abstract: Pacitan is included in the Gunung Sewu karst area in the Southern Mountain Zone, and carbonate rocks dominate the constituent rocks. Karst has a unique drainage system because it is dominated by subsurface flow. This research was conducted in Cemeng and Klepu villages, Donorojo sub-district, Pacitan, with 4 track data. Data were collected using the very low frequency electromagnetic (VLF-EM) method with a track length ranging from 200-450 m, a measurement spacing of 5 m, and a transmitter frequency of 19.8 kHz. Data processing uses filtering and inversion, resulting in a cross-section of resistivity values. Based on the subsurface resistivity cross-section profile, the cavity in the carbonate rock layer with a resistivity value of 0-500 Ωm is identified as an underground river. The underground river is found on tracks 1, 2, 3, and 4 near the surface, with a depth of about 30 m below the surface.
Institution: Institut Teknologi Sepuluh Nopember
Language: English
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4404333729