Tatun Volcanic Group geothermal assessment: estimated radiative heat flux and heat loss from satellite thermal time-series datasets

Taiwan's Tatun Volcanic Group (TVG) is an active tectonic zone that moved from tectonic compression zones to crustal expansion. It is a graben, or region of crustal thinning structure, that is favorable to crustal magmatic intrusion. This geologic context supplies heat for the formation of geothermal and volcanic systems. In addition, TVG is a suitable location for geothermal exploration because of the numerous surface thermal characteristics associated with young volcanic rocks. By computing the geothermal radiative heat loss based on the land surface temperature (LST) obtained from thermal sensors on Earth-observing satellites, we can assess the geothermal resource reservoir of TVG. Firstly, the Stefan-Boltzmann law from the LSTs is used to derive the radiative heat flow (RHF). Second, the sum of the heat flux pixel values over the selected geothermal area is used to estimate the overall radiative heat loss (RHL). The background radiative heat loss is then computed, and by deducting the background radiative heat loss from the total radiative heat loss, geothermal (i.e., net) radiative heat loss is determined. The above process determines trends in geothermal radiative heat loss over time. The average value of the four-decade (1984 - 2024) trend of geothermal radiative heat loss at TVG is 211 MW, with an annual rate of increase of 1 MW (MegaWatt) each year. The mean value of heat loss estimation follows the same sequence as the traditional geochemical method used in earlier research. On the other hand, this study's annual growing rate estimation of TVG is noted for the first time. This study shows the advantages and benefits of employing long-term remote sensing datasets in geothermal and volcanic investigations. It is the first attempt to assess TVG's geothermal potential using satellite thermal observations. This application of remote sensing methods in TVG's geothermal investigation shows encouraging outcomes and can be applied to other geothermal systems across the globe.