Identifikasi Akuifer Air Tanah Di Kaki Gunung Api Gamalama Pulau Ternate Menggunakan Data Geolistrik Tahanan Jenis 2-Dimensi

This study aimed to identify the distribution of groundwater aquifers and seawater intrusion at the foot of Mount Gamalama on Ternate Island using 2-dimensional electrical resistivity data. This island has experienced significant eruptions that have caused new deposits to form on its body and have caused the formation of an aquifer layer. Small in size but surrounded by seawater, Ternate Island experiences seawater intrusion at the aquifer zones. We researched using 2-dimensional electrical resistivity techniques on nine lines in the eastern and southern parts of the Island, namely the Bandara, FKIP, PDAM, Kayu Merah, Skep, Lapangan Fitu, Sasa, and Takome lines. Each line has a length of 75 meters to 230 meters. This measurement was carried out in the direction parallel to the shoreline using two electrode configurations: the Wenner and the Wenner-Schlumberger. Electrode spacing was 10m. The results showed that aquifer zones with a resistivity value of 10 – 150 Ohm.m exist in the eastern and southern parts of the island. We found seawater intrusion in the eastern part of the island on the PDAM lines with a resistivity value of 1 – 10 Ohm.m. The zones show high conductance values in the low resistivity range of 3.01 to 3.41 Ohms. Visual evidence reveals that this PDAM line locates at the beach, where Ternate inhabitants utilize groundwater excessively through dug wells.This study aimed to identify the distribution of groundwater aquifers and seawater intrusion at the foot of Mount Gamalama on Ternate Island using 2-dimensional electrical resistivity data. This island has experienced significant eruptions that have caused new deposits to form on its body and have caused the formation of an aquifer layer. Small in size but surrounded by seawater, Ternate Island experiences seawater intrusion at the aquifer zones. We researched using 2-dimensional electrical resistivity techniques on nine lines in the eastern and southern parts of the Island, namely the Bandara, FKIP, PDAM, Kayu Merah, Skep, Lapangan Fitu, Sasa, and Takome lines. Each line has a length of 75 meters to 230 meters. This measurement was carried out in the direction parallel to the shoreline using two electrode configurations: the Wenner and the Wenner-Schlumberger. Electrode spacing was 10m. The results showed that aquifer zones with a resistivity value of 10 – 150 Ohm.m exist in the eastern and southern parts of the island. We found seawater intrusion in the east part of the island on the PDAM lines with a resistivity value of 1 – 10 Ohm.m. The zones show high conductance values in the low resistivity range of 3.01 to 3.41 Ohms. Visual evidence reveals that this PDAM line locates at the beach, where Ternate inhabitants utilize groundwater excessively through dug wells

Analisa Resistivitas Batuan dengan Menggunakan Parameter Dar Zarrouk dan Konsep Anisotropi

Telah dilakukan analisa resistivitas batuan dengan menggunakan parameter Dar Zarrouk dan konsep anisotropi pada data Vertical Electrical Sounding (VES) konfigurasi schlumberger lapangan FINAL#. Parameter Dar Zarrouk digunakan untuk menghitung resistivitas transversal maupun longitudinal untuk kemudian didapatkan nilai resistivitas media dan koefisien anisotropi lapangan. Digunakan dua data VES saling tegak lurus dan satu data sumur sebagai referensi yang letaknya paling dekat dengan kedua line tersebut. Data hasil pengolahan kemudian dikorelasikan dengan data sumur sebagai data insitu untuk mengetahui kecocokan antara keduanya. Dari hasil korelasi didapat bahwa data pengolahan berdasarkan parameter Dar Zarrouk nilainya mampu mendekati data sumur yang ada dengan range 1 - 10 Ωm. Zonasi lapangan berdasarkan nilai resistivitas mengindikasikan bahwa lapangan FINAL# memiliki litologi shale dan batuan karbonat berpori yang terisi oleh fluida

Multi-dimensional Inversion Modeling of Surface Nuclear Magnetic Resonance (SNMR) Data for Groundwater Exploration

Groundwater is an important economic source of water supply for drinking water and irrigation water for agriculture. Surface nuclear magnetic resonance (SNMR) sounding is a relatively new geophysical method that can be used to determine the presence of culturally and economically important substances, such as subsurface water or hydrocarbon distribution. SNMR sounding allows the determination of water content and pore size distribution directly from the surface. The SNMR method is performed by stimulating an alternating current pulse through an antenna at the surface in order to confirm the existence of water in the subsurface. This paper reports the development of a 3-D forward modeling code for SNMR amplitudes and decay times, after which an improved 2-D and 3-D inversion algorithm is investigated, consisting of schemes for regularizing model parameterization. After briefly reviewing inversion schemes generally used in geophysics, the special properties of SNMR or magnetic resonance sounding (MRS) inversion are evaluated. We present an extension of MRS to magnetic resonance tomography (MRT), i.e. an extension for 2-D and 3-D investigation, and the appropriate inversions