The research, conducted by the National Institute of Geophysics and Volcanology (INGV) and the University of Naples Federico II, offers new perspectives for understanding the physical processes underlying earthquakes.
A new study conducted by a team of researchers from theNational Institute of Geophysics and Volcanology (INGV) and dellUniversity of Naples Federico II highlighted the role of Earth's heat flow in controlling the distribution of earthquake magnitudes globally.
The research “Crustal Heat Flow Drives the Earthquake Magnitude Distribution”, the results of which were published in the scientific journal Geophysical Research Letters, analyzes the spatial variations of the so-called b-value, a fundamental parameter of the Gutenberg-Richter law that describes the ratio of earthquakes of different magnitudes in a given area. To this end, a global catalog of over 22.000 earthquakes recorded between 1980 and 2023 was examined.
"The b-value is a crucial indicator for understanding seismicity: a high value indicates a prevalence of small events, while a low value signals a greater probability of strong earthquakes. - explains Matteo Taroni, researcher at INGV and co-author of the study - By analyzing seismic data at a global level, we wanted to investigate the physical causes of these variations. We observed that the ratio of earthquakes of different magnitudes does not vary randomly, but is closely linked to the thermal properties of the different crustal regions analyzed..
The results highlight a correlation between the heat flow coming from the Earth's interior and the b-value. In particular, in regions characterized by high heat flow, the b-value It is higher, and smaller earthquakes are more frequent than larger ones. This relationship is consistent across different tectonic contexts and independent of the type of fault movement.
"This study provides solid empirical evidence of the direct link between the statistical behavior of earthquakes and physical processes - points out Roberto Basili, research director at INGV and co-author - Heat flow represents a first-order control on b-value variations at the global level.”
The results of the study could contribute to improving the understanding of the processes underlying seismicity and to making probabilistic forecasts of seismic hazard and risk mitigation strategies more accurate.
Useful links:
National Institute of Geophysics and Volcanology (INGV)
University of Naples Federico II
Epicenters of the earthquakes analyzed in the study (black dots) and heat flow (colored background, in logarithmic scale).