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Abstract

The China Earthquake Administration (CEA) has launched an ambitious nationwide earthquake early warning (EEW) system project, which will consist of approximately 15,000 seismic stations and be the largest EEW system in the world. In 52%, 30% and 17% of Chinese mainland, the inter-station distance will soon be smaller than 50 km, 25 km and 15 km, respectively. The effectiveness of the EEW system expected inside Chinese mainland can be quantified via the metric given by the radius of the blind zone (no-warning zone). Using theoretical network-based method, we generate the spatial distribution of the blind zone radii predicted for the new seismic network based on its configuration. The densified new seismic network is expected to have excellent EEW performance from the perspective of blind zone. The area covered by blind zones that are smaller than 30 km will soon rise from 1.6% to 24.3% inside Chinese mainland, which means that the area will increase by 2.6 million km². We claim that every 1,000,000 RMB (158,000 USD) invested to densifying the planned network will increase the area where the blind zone radius is smaller than 30 km by 3,000 km². Continuing to increase the density of stations in some key regions with the blind zone radii ranging from 20 to 40 km is still necessary to control the unexpected expansion of blind zones due to the possible (and common) stations failure. Our investigation provides a useful reference for the real functioning and further optimization of the EEW system in Chinese mainland.