Estimation of thermal distribution and subsurface structure at Tiris-Mt. Lamongan Geothermal Area using 3D suscebtibility and density modeling

Abstract

Mt. Lamongan, East Java is located at near three major towns around, i.e. Probolinggo, Lumajang, and Jember. Its Mountain indicated saving the potential of geothermal energy. That seems from the existence of geothermal manifestations such as hot springs in Tiris Probolinggo. The hot spring temperature value at the surface is 67°C. Estimation of subsurface temperature distribution, model and the orientation of existing faults are very important to know, to the planning of geothermal exploitation. In this study, we used magnetic and gravity field anomaly data to approximate it. We use Mag3D and Grav3D software from the University of British Columbia (UBC) to make a 3D inversion of magnetic and gravity field data. The inversion is shown the pattern of subsurface susceptibility values and rock density clearly. The susceptibility values correlated with the presence of sub-surface heat source and the rock density is associated with the structural condition, i.e. model and orientation of fault in this area. In this study, we found the subsurface temperature distribution connected with the structural system, i.e. Tiris faults.