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

  • Author(s): Hai-Po Chan and Chung-Pai Chan
  • DOI: 10.3319/TAO.2018.01.22.01
  • Keywords: Tatun Volcanic Group (TVG), Thermal Infrared (TIR) remote sensing, Land Surface Temperature (LST), Radiative Heat Flux (RHF), Landsat 7, Moderate Resolution Imaging Spectroradiometer (MODIS), Hilbert-Huang Transform (HHT), Ensemble Empirical Mode Decomposition (EEMD)
  • Landsat 7 ETM+ imagery is used to retrieve the LST in TVG
  • Occurrences of hot springs are in good agreement with retrieved anomaly areas
  • TIR Remote Sensing is integrated for monitoring volcanic activity in Taiwan

Tatun Volcanic Group (TVG) in the northernmost tip of Taiwan is an area of active fumaroles and hot springs with the possible magnitude of VEI 4 (volcanic explosivity index), that can devastate the Taipei metropolitan area of approximately 8 million populations if eruption occurs. Newest studies have claimed that TVG is an active volcano area. 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), and MODIS 8-day average LST products are adopted for monitoring Jinshan fault zone of TVG. Validated results imply that occurrences of hot springs and fumaroles conform to LST anomaly distribution. The overall temperature in E-W ridge is higher than the SW-NE ridge in TVG. Thermal anomaly patterns also indicate that distributions of higher LST areas appear correlating with the development of Jinshan fault; for argument verification, Hilbert-Huang Transform (HHT) was applied for decomposing MODIS 8-day average LST time series (2002-2016) in Jinshan fault zone. Based on HHT the possible related physical processes underneath Ensemble Empirical Mode Decomposition (EEMD) components, which are the key parts of 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 indicates the TVG’s current status is quite calm and resting.

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