The New Frontiers of Earthquake Early Warning Systems

There are a few seconds between an earthquake starting to rupture and its possibly devastating effect on population and infrastructures. Earthquake Early Warning (EEW) Systems address the issue of how to take advantage of this delay by triggering alerts and actions that may mitigate losses. The first weaker seismic signals (P waves) radiated by a potentially damaging earthquake travel about twice as fast as the later large amplitude (S or surface waves) that are more likely to cause damage. The information about the earthquake source size and location, as inferred from real-time processing of the early seismic waves collected in the vicinity of the source, can be sent to more distant sites in advance of the arrival of strong shaking.

EEW Systems are advanced seismic monitoring infrastructures able to detect the ongoing event, estimate its potential damage and send a warning to a target site. Such a warning can alert a community and activate security measures, that may contribute to the real-time vulnerability reduction to minimize losses, or in directing rescue operations immediately after an earthquake for emergency preparedness.

Within this context, continuous progress needs to be done to improve the real-time performance of EEW Systems. Fundamental research is necessary to understand the preparatory and nucleation phases of earthquakes and for developing physics-based models relating to real-time observed quantities and source parameters. Advanced methodologies and algorithms for refined models of the earthquake source and wave propagation across the media are needed to provide realistic ground motion estimates and earthquake impact forecasting. Innovative technologies have to be explored for seismic monitoring and control, including low-cost sensors, seismic arrays, fibre-optic cables for ground motion monitoring, software platforms for alert management, smartphone alert dissemination, as well as crowd-sourced approaches to detect earthquakes and understand their impact on buildings and persons. Finally, the community of end-users and stakeholders needs to be prepared to receive well-conceived messages and start proper response to alerts, to optimally benefit from the warning.
This Research Topic aims to collect a broad range of new contributions to the development of reliable and robust EEW Systems that account for a variety of aspects related to physical, methodological and technological issues. We also wish to collect examples and case studies of the application of EEW Systems, using both existing systems and real or simulated earthquake waveforms. Finally, we appreciate review papers, reporting the updated status of operative/under-development EEW Systems around the world, as well as cost-benefit studies.

We welcome contributions about:
• New methods for real-time estimation of earthquake source properties;
• Real-time analysis of recorded seismic signals for the ground shaking prediction;
• Quantitative comparison of existing methods for real-time estimation of earthquake source properties and ground shaking prediction;
• Application of innovative technologies to Earthquake Early Warning;
• Crowd-sourcing approaches for earthquake detection and alert dissemination;
• Status/progress of Earthquake Early Warning Systems around the world;
• Cost-benefit analyses for Earthquake Early Warning;
• Case studies and examples of Earthquake Early Warning Systems through the use of both real earthquake data and simulated waveforms.