A PARSIMONIOUS APROACH FOR SUBSURFACE TEMPERATURE ESTIMATION BASED ON MAGNETOTELLURIC (MT) DATA FROM WAE SANO GEOTHERMAL FIELD: PENDEKATAN PARSIMONI UNTUK ESTIMASI TEMPERATUR BAWAH PERMUKAAN BERDASARKAN DATA MAGNETOTELLURIK (MT) DARI LAPANGAN GEOTERMAL WAE SANO

Iqbal Takodama; Tony Rahadinata; Hendra Grandis

doi:10.47599/bsdg.v21i1.594

Penulis

Iqbal Takodama Pusat Sumber Daya Mineral Batubara dan Panas Bumi, Indonesia Penulis
Tony Rahadinata Pusat Sumber Daya Mineral Batubara dan Panas Bumi, Indonesia Penulis
Hendra Grandis Institut Teknologi Bandung, Indonesia Penulis

DOI:

https://doi.org/10.47599/bsdg.v21i1.594

Kata Kunci:

Gradien Resistivitas, Gradien Temperatur, Transformasi Bostick, Arrhenius, Wae Sano

Abstrak

Metode magnetotelurik (MT) secara umum digunakan dalam eksplorasi geotermal untuk mendelineasi zona konduktif yang sering diinterpretasikan sebagai lapisan penudung. Namun, zona konduktif tidak selalu mencerminkan keberadaan temperatur tinggi sehingga berpotensi menimbulkan ambiguitas dalam interpretasi. Makalah ini membahas pendekatan parsimoni berbasis persamaan Arrhenius untuk memperkirakan gradien temperatur bawah-permukaan dari gradien resistivitas, hasil analisis resistivitas-semu dan transformasi Bostick. Metode ini diterapkan pada 102 titik MT di lapangan Wae Sano, NTT dan dikalibrasi dengan data log temperatur pada dua sumur landaian suhu. Hasilnya menunjukkan korelasi linier yang kuat (R² = 0,996) dengan nilai RMSE ~8%. Model temperatur memperlihatkan kubah isotermal ~225°C pada kedalaman 500 - 750 m di sektor tenggara Danau Sano Nggoang yang diinterpretasikan sebagai zona upflow dari sistem geotermal. Pendekatan ini efektif sebagai metode assesmen cepat untuk delineasi awal prospek geotermal serta mendukung optimalisasi desain survei MT pada tahap eksplorasi awal.

Biografi Penulis

Iqbal Takodama, Pusat Sumber Daya Mineral Batubara dan Panas Bumi, Indonesia

Tim Panas Bumi - Pusat Sumber Daya Mineral Batubara dan Panas Bumi

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