Subsurface Structure around Mas Crater Area of Papandayan Volcano, Indonesia based on Magnetotelluric (MT) and Geomagnetic Data
Dieno Diba, Nurhasan
Physics Department, Bandung Institute of Technology, Bandung, Indonesia
Abstract
Papandayan Volcano is an active volcano located near Garut Regency, West Java, Indonesia. Magnetotelluric (MT) data acquisition was carried out in the Crater Mas area in 2009 with a total of 13 measurement points. This data acquisition was performed using a remote reference method to obtain better data quality by reducing measurement noise. The geomagnetic data acquisition was carried out in January 2019 in the crater area using a set of G-856AX Memory MagTM Proton Precision Magnetometer (PPM) with a total of 259 points. The result of MT modeling shows that the structure could be divided horizontally into two layers, namely the conductive layer at a depth up to 1km and the resistive layer at a depth of more than 1km from the surface. Conductive layer located near the surface may be interpreted as the presence of water or clay mineral. The two-dimensional forward modeling of geomagnetic result shows that the rocks with relatively low susceptibility values below the surface causes the anomaly at a depth of 30 to 100 meters. The low susceptibility values of the rocks might have been caused by thermal demagnetization due to high temperatures.
Keywords: Geomagnetic, Magnetotelluric, Resistivity, Papandayan Volcano, Susceptibility
Topic: Earth and Planetary Sciences