| || || Hot springs -- Fiji -- Rabulu|
| || || Geophysical investigation of the hot spring site in Rabulu, Fiji|
Author: Lal, Alvin Abinesh
Institution: University of the South Pacific.
Subject: Hot springs -- Fiji -- Rabulu, Geophysics -- Research -- Fiji -- Rabulu
Call No.: Pac QE 528 .L35 2016
Copyright:Over 80% of this thesis may be copied without the authors written permission
Abstract: Geothermal energy offers an alternative to fossil fuels and provides substantial benefits for our climate, health and economy. Hot spring sites and their underneath groundwater systems are important natural resources for geothermal utilization. An investigation of the hot spring site is necessary in the early phases for development of associated geothermal energy systems. The present work is a pilot study of a long term hydrogeophysical project being developed in Fiji, and is the first of its kind work, covering a survey area of 6075 m2. A geophysical investigation of a hot spring system located in Rabulu, Fiji was carried out from October 2014 to March 2015. Self-potential (SP), ground temperature and soil carbon dioxide (CO2) concentrations are important geophysical parameters that were measured and investigated for their behavioral interlinkages at the site. Standard geophysical equipment and procedures were used in conducting these measurements. Linear SP profiles and spatial distributions indicated obvious anomalous zone at the hot spring site. SP profile analysis highlighted thermal water upwelling zones and SP/Elevation interpretation indicated the flow of groundwater from elevated areas. Ground temperature results from thermal probes up to 1 m depth showed consistent increase in ground temperatures, indicating possible deeper high thermal gradient in the area. Soil CO2 concentration profile also displayed similar features with SP and ground temperature results. Constant hot water temperature, discharge rate, ion contents and energy flux gave an indication of a steady geothermal activity in the vicinity of the hot spring. Results from this investigation disclosed that passive SP surveys coupled with ground temperature measurements and soil CO2 measurements are suited for further investigations in the area. Preliminary results from this pilot study indicate that this site may offer a good alternative energy source and merits further detailed investigations.