![]() However, high costs preclude their worldwide implementation. Current solutions, such as densifying on-land seismic networks and installing cabled ocean bottom sensor networks, are implemented in Japan 7 and Canada 8. Thus, valuable time may be lost waiting for seismic waves to reach on-land stations 6. While most of the largest and most hazardous earthquakes on Earth occur offshore in subduction zones, the vast majority of seismic stations are located on-land. The performance of EEW systems largely depends on the spatial distribution of available seismic sensors 5 for fast and robust warning issuance, seismic instruments should be installed in proximity to active faults, where earthquakes are expected to occur. Following rupture initiation, warning may be issued by analyzing recorded ground motions in real-time to assess the earthquake’s damage potential. While earthquake prediction remains out of reach, continuous seismic monitoring has enabled earthquake early warning (EEW) systems that provide alerts to population centers and critical infrastructure seconds to tens of seconds before intense ground shaking is felt 1, 2, 3, 4. The results demonstrate the potential of DAS-based EEW and the significant time-gains that can be achieved compared to the use of standard sensors, in particular for offshore earthquakes. DAS strain measurements of earthquakes from different regions are converted to ground motions using a real-time slant-stack approach, magnitudes are estimated using a theoretical earthquake source model, and ground shaking intensities are predicted via ground motion prediction equations. ![]() ![]() In this work, we harness available optical fiber infrastructure for EEW using the novel approach of distributed acoustic sensing (DAS). However, while the most hazardous earthquakes on Earth occur underwater, most seismological stations are located on-land precious seconds may go by before these earthquakes are detected. For optimal warning times, seismic sensors should be installed as close as possible to expected earthquake sources. Earthquake early warning (EEW) systems provide seconds to tens of seconds of warning time before potentially-damaging ground motions are felt. ![]()
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