Electronic Theses and Dissertation

Studi penentuan struktur lapisan bawah permukaan menggunakan metode geolistrik tahanan jenis telah dilakukan di kawasan Gunung Paro, Kecamatan Lhoong, Kabupaten Aceh Besar, Provinsi Aceh. Penelitian ini bertujuan untuk mengetahui struktur lapisan bawah permukaan berdasarkan variasi nilai resistivitas dan menginterpretasi gambaran bawah permukaan berupa struktur 2D berdasarkan model resistivitas. Pengukuran dilakukan menggunakan empat lintasan, panjang Lintasan 1, 2 dan 3 adalah 112 m dengan jarak spasi elektroda 2 m dan jumlah elektoda 56 unit, khusus Lintasan 4 diukur memotong Lintasan 1, 2 dan 3 memiliki jarak spasi 4 m panjang Lintasan 224 m. konfigurasi yang digunakan adalah Wenner-Schlumberger. Pengolahan data dilakukan menggunakan software Earthimager untuk memperoleh hasil berupa citra 2D. hasil penelitian menunjukkan bahwa nilai resistivitas yang diperoleh pada daerah penelitian berkisar antara 3.0 ˗ 1000 Ωm dari ke empat Lintasan pengukuran. Berdasarkan nilai resistivitas yang diperoleh nilai resistivitas 3.0-100 Ωm yang dicitrakan dengan warna biru tua, biru muda dan hijau terdiri dari lempung. Nilai resistivitas 200-1000 Ωm yang dicitrakan dengan warna kuning dan merah terdiri dari batu pasir. Berdasarkan hasil model 2D struktur lapisan di bawah permukaan pada kawasan kaki Gunung Paro bervariasi dan bila ditinjau dari kemiringan lokasi, maka kawasan tersebut berpotensi longsor. Hasil pengukuran dan interpretasi data di kawasan penelitian berhasil menujukkan struktur lapisan bawah permukaan di kawasan Gunung Paro, Lhoong, Aceh Besar.

Kata kunci: Lapisan bawah permukaan, resistivitas batuan, konfigurasi Wenner-
Schlumberger.

A study to determine the structure of the subsurface layer using the geoelectrical resistivity method was conducted in the Paro Mountain area, Lhoong District, Aceh Besar Regency, Aceh Province, China. This study aims to determine the structure of the subsurface layer based on variations in resistivity values and to interpret the subsurface image in the form of a 2D structure based on the resistivity model. Measurements were carried out using four trajectories, the length of Trajectories 1, 2, and 3 is 112 m with an electrode spacing of 2 m and the number of electrodes is 56 units; Trajectories 4 were measured by intersecting Trajectories 1, 2, and 3 with a spacing of 4 m, and the length of the trajectories was 224 m. The configuration used was Wenner-Schlumberger. Data processing was performed using the Earthimager software to obtain results in the form of 2D images. the results of the study showed that the resistivity values obtained in the study area ranged from 3.0 ˗ 1000 Ωm from the four measurement Trajectories. Based on the resistivity values obtained, the resistivity values of 3.0-100 Ωm imaged in dark blue, light blue, and green consisted of clay. The resistivity values of 200-1000 Ωm imaged in yellow and red, consist of sandstones. Based on the results of the 2D model, the structure of the layers below the surface in the foothills of Mount Paro varied, and when viewed from the slope of the location, the area had the potential for landslides. The results of measurements and data interpretation in the research area have succeeded in showing the structure of the subsurface layers in the Mount Paro, Lhoong, and Aceh Besar areas. Key words: Subsurface layers, rock resistivity, configuration Wenner- Schlumberger.