Unusual Surface Latent Heat Flux Variations and Their Critical Dynamics Revealed before Strong Earthquakes
Soujan Ghosh,
Swati Chowdhury,
Subrata Kundu,
Sudipta Sasmal,
Dimitrios Z. Politis,
Stelios M. Potirakis,
Masashi Hayakawa,
Suman Chakraborty,
Sandip K. Chakrabarti
Affiliations
Soujan Ghosh
Indian Centre for Space Physics, 43, Chalantika, Garia Station Road, Kolkata 700084, India
Swati Chowdhury
Indian Centre for Space Physics, 43, Chalantika, Garia Station Road, Kolkata 700084, India
Subrata Kundu
Indian Centre for Space Physics, 43, Chalantika, Garia Station Road, Kolkata 700084, India
Sudipta Sasmal
Indian Centre for Space Physics, 43, Chalantika, Garia Station Road, Kolkata 700084, India
Dimitrios Z. Politis
Department of Electrical and Electronics Engineering, Ancient Olive Grove Campus, University of West Attica, 12241 Egaleo, Greece
Stelios M. Potirakis
Department of Electrical and Electronics Engineering, Ancient Olive Grove Campus, University of West Attica, 12241 Egaleo, Greece
Masashi Hayakawa
Hayakawa Institute of Seismo Electromagnetics Co., Ltd., University of Electro-Communications Alliance Center, 521, 1-1-1 Kojma-cho, Chofu, Tokyo 182-0026, Japan
Suman Chakraborty
Physical Research Laboratory, Navrangpura, Ahmedabad 380009, India
Sandip K. Chakrabarti
Indian Centre for Space Physics, 43, Chalantika, Garia Station Road, Kolkata 700084, India
We focus on the possible thermal channel of the well-known Lithosphere–Atmosphere–Ionosphere Coupling (LAIC) mechanism to identify the behavior of thermal anomalies during and prior to strong seismic events. For this, we investigate the variation of Surface Latent Heat Flux (SLHF) as resulting from satellite observables. We demonstrate a spatio-temporal variation in the SLHF before and after a set of strong seismic events occurred in Kathmandu, Nepal, and Kumamoto, Japan, having magnitudes of 7.8, 7.3, and 7.0, respectively. Before the studied earthquake cases, significant enhancements in the SLHF were identified near the epicenters. Additionally, in order to check whether critical dynamics, as the signature of a complex phenomenon such as earthquake preparation, are reflected in the SLHF data, we performed a criticality analysis using the natural time analysis method. The approach to criticality was detected within one week before each mainshock.
