First posted March 10, 2021 Revised 24, For additional information, contact: Earthquake Science Center—Menlo Park, Calif. OfficeU.S. Geological Survey345 Middlefield Road, MS 977Menlo CA 94025 The ShakeAlert® earthquake early warning system has been live since October 2019 for the testing of public alerting to mobile devices in California and will soon begin this modality Oregon Washington. Pac...

PROBLEM On 6 February 2013, an 8.0 magnitude earthquake generated a tsunami that struck the Santa Cruz Islands, Solomon Islands, killing 10 people and displacing over 4700. APPROACH A post-disaster assessment of the risk of epidemic disease transmission recommended the implementation of an early warning alert and response network (EWARN) to rapidly detect, assess and respond to potential outb...

Earthquake Alarms Systems, ElarmS, is a methodology for providing warning of forthcoming ground shaking during earthquakes. The approach uses a network of seismic instruments to detect the first-arriving energy at the surface, the P-waves, and translate the information contained in these low amplitude waves into a prediction of the peak ground shaking that follows. The instruments closest to th...

Large magnitude earthquakes in urban environments continue to kill and injure tens to hundreds of thousands of people, inflicting lasting societal and economic disasters. Earthquake early warning (EEW) provides seconds to minutes of warning, allowing people to move to safe zones and automated slowdown and shutdown of transit and other machinery. The handful of EEW systems operating around the w...

We present a new strategy to estimate the geometry of a rupture on a finite fault in real time for earthquake early warning. We extend the work of Cua and Heaton who developed the virtual seismologist (VS) method (Cua, 2005), which is a Bayesian approach to seismic early warning using envelope attenuation relationships. This article extends the VS method to large earthquakes where fault finiten...

[1] We examine five different methods to estimate an earthquake’s magnitude using only P wave data for use in earthquake early warning systems. We test two input parameters: the maximum predominant period of the P wave (τp) and the displacement amplitude of the P wave’s vertical component (Pd). We apply our algorithms to 174 earthquakes 3.0<M< 8.0 from California and Japan that have also been u...

An earthquake early warning system (EEWS) is a monitoring infrastructure that allows alerting strategic points (targets) before the arrival of strong shaking waves during an earthquake. In region like Central Italy, struck by recent and historical destructive earthquakes, assessment implementation EEWS significant challenge due to proximity seismic sources many potential targets, such as towns,...