Is it possible to predict earthquakes? It is still an open question. An INGV study published in the journal Nature - Scientific Reports reveals electromagnetic anomalies in the ionosphere before major earthquakes.
A statistically significant determination of concentrations of electromagnetic anomalies in the ionosphere before the occurrence of earthquakes of magnitude equal to 5.5 or greater, and with hypocentral depth up to 50 km. This is the most important result of the study "Precursory worldwide signatures of earthquake occurrences on Swarm satellite data" by an interdisciplinary group of researchers from the Italian National Institute of Geophysics and Volcanology (INGV), Planetek Italia srl and the European Space Agency (ESA) just published in the journal Scientific Reports of the editorial group Nature.
Thanks to ESA's financial support for the SAFE (SwArm For Earthquake study) project, the INGV-led team analyzed magnetic and plasma data in the ionosphere - the ionized layer of the upper atmosphere, which is between 60 and the 1000 km high - measured at an altitude of about 500 km by the three satellites of the 'Swarm' project, the ESA mission created to improve knowledge of the Earth's magnetic field.
Going beyond the aims of the Swarm mission itself, the research team sought 'electromagnetic' traces coupling with the Earth's lithosphere during large earthquakes. The main result of the research was a statistically significant detection of concentrations of electromagnetic anomalies in the ionosphere before the occurrence of earthquakes of magnitude equal to 5.5 or greater, and with hypocentral depth up to 50km.
According to Angelo De Santis, INGV research director and first author of the article, "the importance of this work is twofold. On the one hand, we have been able to statistically confirm that, during the preparatory phase of a strong earthquake, there is a coupling between the lithosphere, where earthquakes occur, and the overlying ionosphere. For another aspect, then, Rikitake's empirical law was confirmed with satellite data. "
It is "a law proposed in the 1980s for precursors to the ground, so the anticipation time of the precursors depends on the magnitude of the earthquake: the longer the precursor advance time, the stronger the earthquake will be."
"The result of our work is very important, but despite the anomalies identified are statistically linked to the occurrence of earthquakes, they still do not allow to be able to make predictions of seismic events, for which it is necessary to move from a statistical approach to a deterministic one, which will require further studies in the future" adds De Santis.
"Our team is still enthusiastically collaborating with the INGV on this important study, which turns on a small, but important, light in understanding such devastating and still unpredictable phenomena. As part of the SAFE-SWARM project , we have created the management infrastructure for the organization and fusion of satellite and ground data useful for extracting the information necessary for analysis, enhancing our skills developed in operational contexts" says Cristoforo Abbattista, head of the SpaceStream SBU Planetek Italia.