Satellite thermal monitoring of gas emission at Mefite D’ansanto Lake by ECOSTRESS time series analysis

Mefite d'Ansanto, located in the seismically active Southern Apennines mountain chain (Avellino, Italy), is recognized as the Earth's largest natural emitter of low-temperature CO
2
-rich gasses from a non-volcanic setting. This site serves as a unique natural laboratory to explore the dynamic relationship between fluids and seismic activity. To monitor gas emissions at Mefite in Valle d’Ansanto Lake, land surface temperature time series (LST) from 2018 to 2023 were analyzed. This data was collected using the NASA-JPL ECO System Spaceborne Thermal Radiometer Experiment (ECOSTRESS).The potential usefulness of the ECOSTRESS surface temperature time series for detecting thermal anomalies was then evaluated. A measure of data spread was used as a statistical criteria, to eliminate noisy or cloudy ECOSTRESS images. Then, thermal anomalies were obtained by a non-gaussian fit.The analysis revealed some anomalous dates between 2019 and 2022, of which approximately 70% were potentially related to seismic events that occurred not so far from Lake Mefite and in the same period, making us confident in considering the thermal anomalies present due to large losses of CO
2
, triggered by significant surrounding seismic activity.