Magnitude-Period Scaling Relations for Japan and the Pacific Northwest: Implications for Earthquake Early Warning

Lockman, Andrew B.; Allen, R. M.

doi:10.1785/0120040091

Cited by 24 publications

(9 citation statements)

References 26 publications

(34 reference statements)

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“…The Earthquake Alarm Systems (ElarmS) methodology [ Allen and Kanamori , 2003] has been tested using data from southern California, Taiwan, Japan and the Pacific Northwest of the United States [ Olson and Allen , 2005; Lockman and Allen , 2007], and uses the maximum predominant period ( τ p max ) of the first 1 to 4 s of the P wave as an estimate of earthquake magnitude. The ElarmS methodology has been shown to be effective in these areas for M 3 and larger earthquakes [ Allen and Kanamori , 2003; Lockman and Allen , 2005; Olson and Allen , 2005; Allen , 2006; Lockman and Allen , 2007; Allen , 2007]. In the process of testing ElarmS in northern California, we find that using both τ p max and the peak amplitude of the P wave improves the accuracy of the ElarmS magnitude estimate.…”

Section: Introductionmentioning

confidence: 99%

Toward earthquake early warning in northern California

2007

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[1] Earthquake early warning systems are an approach to earthquake hazard mitigation which takes advantage of the rapid availability of earthquake information to quantify the hazard associated with an earthquake and issue a prediction of impending ground motion prior to its arrival in populated or otherwise sensitive areas. One such method, Earthquake Alarm Systems (ElarmS) has been under development in southern California and, more recently, in northern California. Event magnitude is estimated using the peak amplitude and the maximum predominant period of the initial P wave. ElarmS incorporates ground motion prediction equations and algorithms from ShakeMap for prediction of ground motions in advance of the S wave arrival. The first peak ground motion estimates are available 1 s after the first P wave trigger, and are updated each second thereafter for the duration of the event. The ElarmS methodology has been calibrated using 43 events ranging in size from M L 3.0 to M w 7.1 that occurred in northern California since 2001. We present the results of this calibration, as well as the first implementation of ElarmS in an automated, noninteractive setting and the results of 8 months of noninteractive operation in northern California. Between February and September 2006, ElarmS successfully processed 75 events between M d 2.86 to M w 5.0. We find that the ElarmS methodology processed these events reliably and accurately in the noninteractive setting. The median warning time afforded by this method is 49 s at the major population centers of the Bay Area. For these events the magnitude estimate is within an average of 0.5 units of the network-derived magnitude, and the ground motion prediction from ElarmS is within an average of 0.1 units of the observed modified Mercalli intensity.

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Section: Introductionmentioning

confidence: 99%

Toward earthquake early warning in northern California

2007

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“…Nakamura's approach is to use the predominant period, that is, the frequency content, of the first few seconds of the P-wave to estimate the magnitude of an earthquake. Similar magnitude-frequency scaling relations have been developed for various regions around the world (Allen and Kanamori, 2003;Kanamori, 2005;Lockman and Allen, 2007;Nakamura, 2004;Simons et al, 2007;Wu and Kanamori, 2005a,b), although the approach also has its detractors (e.g., Rydelek and Horiuchi, 2006; see also Olson and Allen, 2006 response). Observations from the first few seconds of P-waves recorded within $150 km of the epicenter of 3 M 8.3 earthquakes around the world show a scaling relation between magnitude and frequency content, t max p , as shown in Figure 14 (Olson and Allen, 2005).…”

Section: S-waves Versus P-wavesmentioning

confidence: 64%

Earthquake Hazard Mitigation: New Directions and Opportunities

Allen

2007

Treatise on Geophysics

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“…τ max p is computed for each triggered vertical channel within 100 km. While single observations of τ max p show wide scattering, magnitude estimates tend to be stable and reliable when averaged over at least four stations (Lockman and Allen, 2007). Observations for Southern California (Allen and Kanamori, 2003), Northern California (Wurman et al, 2007), and from a global data set (Olson and Allen, 2005) indicate that the dominant period scales with magnitude over a wide range of magnitudes (M 3.0-8.3).…”

Section: Elarms Methodologymentioning

confidence: 88%

The Potential for Earthquake Early Warning in Italy Using ElarmS

Olivieri¹,

Allen²,

Wurman³

2008

Bulletin of the Seismological Society of America

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The new Italian National Seismic Network (INSN) is a dense network of broadband stations deployed for monitoring Italian seismicity. The network consists of 250 stations with a typical station spacing of ∼40 km. Earthquake early warning is the rapid detection of an event in progress, assessment of the hazard it poses, and transmission of a warning ahead of any significant ground motion. We explore the potential for using the INSN real-time network for the purpose of earthquake early warning. We run the ElarmS early warning methodology off-line using a data set of more than 200 events with magnitudes between 2.5 and 6.0. A scaling relation for magnitude determination from the dominant period of the first seconds of signal following the P onset is developed from the data set. The standard deviation in the magnitude estimates using this approach is 0.4 magnitude units, and all event magnitude estimates are within 0:75 magnitude units of the true magnitude. Given the existing distribution of seismic stations it takes an average of 10 sec after event initiation before the P wave has been detected at four stations. If we require a detection at four stations before issuing the first alert, then the blind zone, within which no warning would be available, has a radius of ∼37 km. The ElarmS methodology can provide a warning earlier than this but with a greater uncertainty. An assessment of past damaging earthquakes across Italy shows that applying ElarmS with the existing seismic network could provide warning to population centers in repeats of past events. For example, in a repeat of the 1980 Irpinia earthquake Naples could receive an ∼15sec warning. The variations in the size of the blind zone and warning times for different regions can be used as a guide to selecting strategic locations for future station deployments.

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Magnitude-Period Scaling Relations for Japan and the Pacific Northwest: Implications for Earthquake Early Warning

Cited by 24 publications

References 26 publications

Toward earthquake early warning in northern California

Toward earthquake early warning in northern California

Earthquake Hazard Mitigation: New Directions and Opportunities

The Potential for Earthquake Early Warning in Italy Using ElarmS

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