Hawaii Geothermal Resource Assessment Program, Western State Cooperative, direct heat resource assessment phase I, final report

Abstract

A regional geothermal resource assessment has been conducted for the major islands in the Hawaiian chain. The assessment was made through the compilation and evaluation of the readily accessible geological, geochemical, and geophysical data for the Hawaiian archipelago which has been acquired during the last two decades. The geologic criteria used in the identification of possible geothermal reservoirs were: age and location of most recent volcanism on the island and the geologic structure of each island. The geochemical anomalies used as traces for geothermally altered ground water were: elevated silica concentrations and elevated chloride/magnesium ion ratios. Geophysical data used to identify subsurface structure which may have geothermal potential were: aeromagnetic anomalies, gravity anomalies, and higher than normal well and basal spring discharge temperatures. Geophysical and geochemical anomalies which may be the result of subsurface thermal effects have been identified on the islands of Hawaii, Maui, Molokai and Oahu.