Self-potential and soil temperature profiling: Case study of Tavua hot spring, Fiji

Abstract

Studies on hot spring regions in Fiji have been conducted by several workers such as (Cox 1982), (Healy 1960) and (Autar 1996). These studies identified several distributions patterns that require further investigation and analysis. There are almost no published works continued from the efforts of previous workers. In the present work, a geophysical investigation of a hot spring was conducted using advanced geophysical techniques to build upon conclusions from preceding works. The Tavua hot spring site, located in northern Viti Levu within the Nakauvadra range was investigated using several geophysical techniques. Self-potential (SP) and soil temperature profiling were carried out within the hot spring. The SP study provided useful information on subsurface fluid flow, clearly delineating upward and downward flows. Good correspondence between SP and soil temperature was also observed. Other hydrological parameters viz., discharge rate and outflow water temperature were evaluated to determine the energy flux of the hot spring. The present methodological study aims to a) investigate the distribution of various geophysical parameters within this area, and b) provide a baseline investigation so that feasibility of further detailed explorations can be determined. To our knowledge, there is no recent published literature concerning geophysical studies on hot springs making this the first of its kind investigation in Fiji.