EGU22-7148
https://doi.org/10.5194/egusphere-egu22-7148
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Investigating the spatiotemporal relationship between thermal anomalies and surface deformation; The Arkalochori Earthquake sequence of September 2021, Crete, Greece.

Sofia Peleli1,2, Maria Kouli1,2, and Filippos Vallianatos1,3
Sofia Peleli et al.
  • 1Institute of Physics of the Earth’s Interior & Geohazards, UNESCO Chair on Solid Earth Physics and Geohazards Risk Reduction, Hellenic Mediterranean University Research Center, Chania, Crete, Greece (sofia.peleli@gmail.com)
  • 2Hellenic Mediterranean University, Department of Electronic Engineering, Romanou 3, Chania, Crete, Greece (mkouli@hmu.gr)
  • 3National and Kapodistrian University of Athens, Faculty of Geology and Geoenvironment, Department of Geophysics and Geothermics, Athens (fvallian@geol.uoa.gr)

Among the different parameters, the fluctuations of Earth's thermally emitted radiation, as measured by sensors on board of satellite systems operating in the Thermal Infra-Red (TIR) spectral range and Earth's surface deformation as recorded by satellite radar interferometry, have been proposed since long time as potential earthquake precursors. Nevertheless, the spatiotemporal relationship between the two different phenomena has been ignored till now.

On September 27, 2021, a strong earthquake of magnitude M5.8 occurred in Crete, near the village of Arkalochori at 06:17:21 UTC, as the result of shallow normal faulting. The epicenter of the seismic event was located at latitude 35.15 N and longitude 25.27 E, while the focal depth was 10 km. Since the beginning of June, almost 4 months earlier, more than 400 foreshocks ranging in magnitude from M0.5 to M4.8 were recorded in the broader area while the strongest aftershock (M 5.3) occurred on September 28th at 04:48:09 UTC.

10 years of MODIS Land Surface Temperature and Emissivity Daily L3 Global 1km satellite records were incorporated to the RETIRA index computation in order to detect and map probable pre-seismic and co-seismic thermal anomalies in the area of tectonic activation. At the same time, SAR images of the Sentinel-1 Copernicus satellite in both geometries of acquisition were used to create the differential interferograms and the displacement maps according to the Interferometric Synthetic Aperture Radar (InSAR) technique. Then, the two kinds of datasets (i.e thermal anomaly maps and crustal deformation maps) were introduced into a Geographic Information System environment along with geological formations, active faults, and earthquakes’ epicenters. By overlapping all the aforementioned data, their spatiotemporal relation is explored.

How to cite: Peleli, S., Kouli, M., and Vallianatos, F.: Investigating the spatiotemporal relationship between thermal anomalies and surface deformation; The Arkalochori Earthquake sequence of September 2021, Crete, Greece., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7148, https://doi.org/10.5194/egusphere-egu22-7148, 2022.

Comments on the display material

to access the discussion