CLUSTER ANALYSIS AS A TOOL FOR EVALUATING THE EXPLORATION POTENTIAL OF KNOWN GEOTHERMAL RESOURCE AREAS

Many Known Geothermal Resource Areas (KGRAs) were identified during a surge of geothermal exploration in the 1970s and 1980s, but were considered to be not economically exploitable at the time. Most of these areas have not been studied in the decades since, but due to advances in power generation technology some may now constitute viable resources. Here we present a low-cost statistical methodology for evaluating the exploration potential of KGRAs using legacy (i.e., literature) data. The method uses a combination of principal component analysis and cluster analysis to compare geochemical data from possible target areas against data from high geothermal potential areas (currently producing geothermal fields) and low geothermal potential control groups. We illustrate the method by applying it to 14 KGRAs and 1 non-thermal control area in southern Idaho and Oregon, using data obtained from government reports, theses, conference papers, and peer-reviewed literature. In addition to being low cost, the method can be applied in situations where the available data were collected at disparate times and/or analyzed by different protocols, and is robust to unevenness in data quality, resolution, and granularity.