Surface heat loss assessment of geothermal fields in the TVZ, using remote sensing and terrestrial techniques

Abstract

Assessment of surface heat loss in geothermal areas can provide information and insight into the size and character of underlying geothermal resources. It also provides a method to monitor changes to a geothermal system and assess geothermal hazards related to movement of subsurface steam. Additionally, variations in fluid flow pathways may result in changes of geothermal feature characteristics and fluid discharge at the surface.
This paper presents findings from heat loss assessments at several geothermal areas within the Taupo Volcanic Zone, including Karapiti (part of the Wairakei-Tauhara geothermal system), Waimangu geothermal valley, Waiotapu Geothermal Field, and Rotorua Geothermal Field. Methods for surface heat loss determination include, direct heat flux measurements using a water-based calorimeter, inferred heat flux assessments from temperature-depth relations, spring and stream flow assessments, and inferred heat fluxes from remote aerial thermal infrared (TIR) and satellite TIR assessments. This paper will compare results and findings from these surveys.