Toward Earthquake Early Warning in Nevada: Seismic Network Configuration and Warning Time Analysis

ABSTRACT The goal of earthquake early warning (EEW) is to send alerts to the public before shaking arrives at their location to allow time to prepare and mitigate the chance of negative outcomes. Nevada is the third most seismically active state in the United States with a large population living in high hazard areas. ShakeAlert, the EEW system active for the west coast of the United States, does not currently support alerts in Nevada, but a future expansion to the state could provide potentially lifesaving benefits to its residents. The first step toward including Nevada in ShakeAlert is analyzing performance metrics relevant to EEW based on the current network geometry and identifying potential improvements. Through systematic analyses of 34 earthquake scenarios, alongside station configuration, grid density testing, and network upgrade scores, we objectively quantify expected warning times and potential improvements while identifying the optimal locations to install new stations. We find that incorporating existing stations from Nevada could provide actionable warning times (at least five seconds and often greater) to Nevada residents for representative earthquake scenarios in the state while also improving warning times to California by about five seconds for events located near the state border. Installation of new stations to further densify the network improves potential warning times, with the recommended density of 20 km station spacing in western Nevada providing on average an additional five seconds of warning with a relatively modest number of new station installations.