A global approach to provide magnitude estimates for earthquake early warning alerts

[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 (τpmax) 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 used in previous calibration studies. We also apply them to 1992 0.2 < M < 5.7 earthquakes that were processed by the real-time Earthquake Alarm Systems in California. We find that τpmax does not scale with magnitude for small earthquakes (M < 3) and is less accurate for large-magnitude earthquakes than using Pd alone. We derive a global scaling relation between Pd and magnitude and conclude that this global relationship provides the most accurate and robust magnitude estimate. This relationship could be applied in earthquake source zones around the world.

[1]  Richard M. Allen,et al.  Designing a Network‐Based Earthquake Early Warning Algorithm for California: ElarmS‐2 , 2014 .

[2]  Richard M. Allen,et al.  Development of the ElarmS methodology for earthquake early warning: Realtime application in California and offline testing in Japan , 2011 .

[3]  S. Wiemer,et al.  Real-time Performance of the Virtual Seismologist Earthquake Early Warning Algorithm in Southern California , 2009 .

[4]  Philip J. Maechling,et al.  CISN ShakeAlert: An Earthquake Early Warning Demonstration System for California , 2014 .

[5]  H. Kanamori,et al.  The Potential for Earthquake Early Warning in Southern California , 2003, Science.

[6]  Richard M. Allen,et al.  Optimal Seismic Network Density for Earthquake Early Warning: A Case Study from California , 2013 .

[7]  Richard M. Allen,et al.  Toward earthquake early warning in northern California , 2006 .

[8]  Thomas H. Heaton,et al.  Real-time Finite Fault Rupture Detector (FinDer) for large earthquakes , 2012 .

[9]  Thomas H. Heaton,et al.  Real‐time testing of the on‐site warning algorithm in southern California and its performance during the July 29 2008 Mw5.4 Chino Hills earthquake , 2009 .

[10]  Gaetano Festa,et al.  Early magnitude and potential damage zone estimates for the great Mw 9 Tohoku‐Oki earthquake , 2012 .

[11]  Richard M. Allen,et al.  Magnitude scaling relations from P‐waves in southern California , 2007 .

[12]  Richard M. Allen,et al.  Application of real‐time GPS to earthquake early warning in subduction and strike‐slip environments , 2013 .

[13]  Richard M. Allen,et al.  Application of real‐time GPS to earthquake early warning , 2011 .

[14]  Yehuda Ben-Zion,et al.  Examination of scaling between earthquake magnitude and proposed early signals in P waveforms from very near source stations in a South African gold mine , 2008 .

[15]  Richard M. Allen,et al.  The deterministic nature of earthquake rupture , 2005, Nature.