Mitigating Tsunamis’ Threats and Destructive Impacts Through Enhanced Navigation Satellite System

Over the last century, 58 tsunamis occurred around the world. Accordingly, those events are rare, but each has a powerful destructive force and is claiming more lives than any other natural hazard – with an average of 4,600 deaths per event. Today, the United Nations estimates that every year about 60 000 people and $4 billion (US$) in assets are exposed to the global tsunami hazard. By 2030, an estimated 50 % of the world’s population will live in coastal areas exposed to natural hazards like floods, storms, and tsunamis. Herein, timely and reliable tsunami warning systems are of critical importance for earthquake-prone coastal areas and communities.

One of those systems has been developed by a team of researchers at the Sapienza University of Roma, the Total Variometric Approach (TVA). Benchmarked during the 2015 Illapel earthquake in Chile, the method showed promising results to support the classic method for the tsunami warning system. During her AXA fellowship within the Roman university, Dr. Michela Ravanelli will aim to improve the reliability and accuracy of real-time tsunami warning systems leveraging the TVA. Coupling two different algorithms, the method demonstrates in a real-time scenario how the simultaneous monitoring of the ground motion and upper atmosphere of the Earth's perturbations can support traditional instruments to improve the quick estimation of the tsunami hazard and better protect coastal livelihoods. To do so, Dr. Ravanelli will focus on improving the atmosphere perturbation measurement technics by developing new procedures to determine the correct altitude where the earthquake and tsunami perturbations are detected in the atmosphere and implementing an atmospheric background filtering method. Thus, she will refine the TVA methodology and the development of a real-time tool to support tsunami warning systems.

The prototype system will be tested at the Observatoire Volcanologique et Sismologique de Guadeloupe and Martinique. Hence the project will provide a real technology transfer from Global Navigation Satellite Systems (GNSS) Ionospheric Seismology to an efficient real-time system. Coupled with already existing warning systems (seismometers, accelerometers, buoys, and tide gages), the developed methodology is expected to have profound and wide-ranging impacts on a tsunami warning systems community. It will provide additional support for decision-makers when it comes to issuing timely warnings and evacuation. The project's long-term objective is to export the system to other places in tsunamigenic zones.

December 2022