Investigation of Deep Aquifers in the Catchment Area of Haruman Peak, Malabar Mountains, Using the Audio-Magnetotelluric (AMT) Method
Asep Harja1), Shofie Dzakia Hanifah2), Nabilah Rahmawati2), Nabila Putri Kusumah2), G. M. Lucki Junursyah3), Kusnahadi Susanto1)

1)Department of Geophysics, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km. 21, Jatinangor, 45363
2}Program Study of Geophysics, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km. 21, Jatinangor, 45363
3Center for Geological Survey, Ministry of Energy and Mineral Resources, Jl. Diponegoro No.57, Bandung, Jawa Barat 40115, Indonesia

Abstract

Haruman Peak, located in the Malabar Mountains in the southern region of the Bandung Basin, plays a significant role as a recharge area for the Bandung-Soreang Groundwater Basin. This recharge function is supported by the area^s dense vegetation, high rainfall, and steep slopes that direct surface water toward the basin. Previous studies using the DC-resistivity method identified a shallow aquifer in the Puncak Haruman area at depths of less than 40 meters. This study aims to explore the presence of deeper aquifers using the Audio-Magnetotelluric (AMT) method.
AMT data acquisition was carried out at six measurement points located in the northern section of a suspected fault zone. The data were processed through 1D inversion to produce resistivity models, which were interpreted to determine subsurface lithology and identify aquifer layers. The results indicate that the subsurface of the Haruman Peak area consists of soil, Malabar-Tilu Volcanics (Qmt), and Waringin-Bedil Andesite of the Old Malabar Formation (Qwb). Aquifer layers were identified with resistivity values ranging from 5 &#937-m to 308 &#937-m, at various depths: MB-02 (805 m), MB-03 (97 m), MB-04 (1,456 m), MB-05 (140 m, 459 m, and 2,080 m), and MB-06 (530 m). It is inferred that deep aquifers at MB-03, MB-05, and MB-06 contribute significantly to groundwater in the southern Bandung Basin.

Keywords: Deep Aquifer, Audio Magnetotelluric, Haruman Peak, Bandung Basin

Topic: Earth Physics and Space Science