Geothermal system characteristics on Northern Ternate region, Indonesia based on interpretation of magnetic anomalies

Abstract

Geothermal resources can be indicated by surface manifestations such as hot springs, hot mud puddles, and geysers. In the Northern Ternate region, in the villages of Tobololo and Sulamadaha, the manisfestation of hot springs is present. Therefore the purpose of this research is to study the geothermal characteristic in the Northern Ternate region, Indonesia, based on interpretation of magnetic anomalies in the hot surface temperature of hot springs. The method employed a fluxgate magnetometer to measure a sample of random temperature. Furthermore it examined for their chemical content to determine their resource type.The results show that the magnetic anomalies value in the Northern Ternate region is of -3678.63 nT up to 2679.57 nT. The contour map is then developed by indicating three levels of magnetic anomalies; low, medium, and high. This is an indication that the area is of geothermal manifestation and it is classified as a hypothetical resource that could become an unexpected reserve. The temperature is measured at 50 cm depth and it shows of 27-38.50 °C. The result of the temperature anomaly in the Tobololo area is due to the flow of hot springs along the coastline. Meanwhile the Sulamadaha area has a smaller hot spring discharge, which is due to hydrothermal activity below the surface. Based on the the geochemistry assessments, both areas have alkali chloride water type.