Exploring and monitoring geothermal and volcanic activity using Satellite Thermal Infrared data in TVG, Taiwan

Abstract

Tatun Volcanic Group (TVG) in the northernmost tip of Taiwan is an active volcano area with the possible magnitude of volcanic explosivity index (VEI) 4 which can devastate the Taipei metropolitan area if eruption occurs. To integrate Thermal Infrared (TIR) remote sensing for exploring geothermal energy and monitoring volcanic activity in TVG, Landsat 7 ETM+ imagery is used to retrieve the Land Surface Temperature (LST) and Radiative Heat Flux (RHF); MODIS 8-day average LST products are adopted for monitoring Jinshan fault zone of TVG. Validated results show that occurrences of hot springs and fumaroles conform to LST anomaly distribution and the overall temperature in E-W ridge is higher than the SW-NE ridge in TVG. Thermal anomaly patterns indicate that distributions of higher LST areas appear correlating with the development of Jinshan fault; for further verification, Hilbert-Huang Transform (HHT) was applied for decomposing MODIS 8-day average LST time series (2002 - 2016) in Jinshan fault zone. Possible related physical processes underneath Ensemble Empirical Mode Decomposition (EEMD) components based on HHT were also elaborated. The inference that LST component with average period around a month (EEMD component 1, i.e., C1) has irregular spikes which is likely associated with earthquakes in TVG has been investigated in detail. Finally, HHT comparison analysis with three active volcanoes in Philippines and Indonesia is performed for assessing the eruption potential of TVG. Preliminary results show that the regular C4 annual cycle from TVG’s LST time series implies the TVG’s current status is calm and resting with no sign of eruption for future decades.