Prospek panas bumi Gunung Ungaran ditunjukkan dengan munculnya manifestasi di permukaan. Penelitian bertujuan untuk mengetahui intensitas medan total, anomali magnetik, dan distribusi panas bumi di sekitar sumber air panas Medini dan Gonoharjo. Pengambilan data geomagnetik dilakukan pada koordinat bujur 110⁰19'47.3"E sampai 110⁰20'12.3"E dan koordinat lintang 7⁰08'56.9"S sampai 7⁰09'42.1"E menggunakan Proton Precession Magnetometer model GSM-19T dengan sensitivitas 0,05 nT, GPS, dan kompas

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... gi. Data intensitas medan magnet total hasil pengukuran diolah dengan melakukan koreksi diurnal dan IGRF, kontinuasi ke atas, pemisahan anomali lokal dan regional, dan reduksi ke kutub. Intensitas medan total daerah penelitian berrnilai 43.000 nT sampai 47.650 nT dengan anomali magnetik bernilai-1.800 nT sampai 2.700 nT. Pola anomali magnetik cenderung berarah tenggara yang diduga menuju pusat panas bumi Gunung Ungaran. Distribusi prospek panas bumi daerah Medini-Gonoharjo berhubungan dengan sebaran luas nilai anomali magnetik rendah akibat alterasi hidrotermal sistem panas pumi sehingga mengalami penurunan sifat kemagnetan batuan. Abstract The existence of Medini and Gonoharjo hot springs in northern part of Ungaran Volcano indicate geothermal energy potential area. This research conducted to determine total magnetic intensity, magnetic anomalous, and geothermal prospect distribution. Geomagnetic research is applied in coordinate longitude 110⁰19'47.3"E to 110⁰20'12.3"E and coordinate latitude 7⁰08'56.9"S to 7⁰09'42.1"E. Data has been collected by Proton Precession Magnetometer model GSM-19T with sensitivity 0,05 nT, GPS, and geological compass. Total magnetic intensity data is processed by diurnal and main field correction, upward continuation, disperate between local and regional anomalous, and reduction to pole. Total magnetic field intensity is spread out between 43.000 nT to 47.650 nT and magnetic anomalous is spread out between-1.800 nT to 2.700 nT which has south east direction to heat source of Ungaran Volcano. Geothermal prospect distribution is related to widespread and dominated of negative magnetic anomalous that indicated demagnetization zone caused by hydrothermal alteration.