Inverse modeling using geomagnetic data of field camp geophysics in Karangsambung (2005-2019)

Abstract

Geomagnetic data from field camp surveys in Karangsambung 2005-2019 were collected and merged. Before 2020 (the restriction of Covid-19 pandemic), there are 4713 and 5984 data of field and base observation in the study area. The purpose of works in this paper are presenting the data collection, simple data processing, and simple calculation of inverse modeling. Fifteen surveys from each year of field camp data acquisition are merged with 2017 survey as reference. The data observation from proton magnetometer are corrected with geomagnetic regional field and diurnal variation (using available data from base observation). Geomagnetic model for 2.5D is calculated using SW-NE slice sections with topographic variation in the study area. The program for inverse model calculation was built to recover distribution of magnetization contrast from surface geomagnetic anomaly. The interpretation of subsurface model should be able to be analyzed and correlated with rock susceptibility and geological surface maps in the study area. From this work, the values of geomagnetic anomaly map are shown in the range of -1600 to 1600 nanoTesla, and the inverse modeling conducted over the Volcanic Breccia in the part of Bukit Brujul area, Basalts and Diabas between Geopark Karangsambung-Parangan-Sadang area, and Clay Breccia in the Sadang-Totogan area.