TriNet “ShakeMaps”: Rapid Generation of Peak Ground Motion and Intensity Maps for Earthquakes in Southern California

Wald, David J.; Quitoriano, Vincent; Heaton, Thomas H.; Kanamori, Hiroo; Scrivner, Craig W.; Worden, C. Bruce

doi:10.1193/1.1586057

Cited by 537 publications

(365 citation statements)

References 0 publications

Supporting

Mentioning

335

Contrasting

Unclassified

Order By: Relevance

“…A good example of this post-earthquake information is ShakeMap (http://earthquake.usgs. gov/eqcenter/shakemap) 11 .…”

Section: Real-time Seismology and Earthquake Early Warningmentioning

confidence: 99%

Earthquake physics and real-time seismology

Kanamori

2008

Nature

Self Cite

View full text Add to dashboard Cite

Simply stated, an earthquake is caused by slip on a fault. However, the slip motion is complex, reflecting the variation in basic physics that governs fault motion in different tectonic environments. Seismologists can learn a great deal about earthquakes from studying the details of slip motion. The size of great earthquakesSeismic slip motion involves a broad 'period' (or frequency) range, at least from 0.1 s to 1 hour, and a wide range of amplitudes, roughly from 1 µm to 30 m. Most seismographs available before the 1960s could record ground motions over only short periods -less than 30 s -which prevented seismologists from studying important details of earthquake processes. In the 1960s, longer-period analogue seismographs became available, allowing seismologists to study great earthquakes (in general, magnitude ≥ 8) over an extended period range; this has resulted in substantial progress in our understanding of earthquakes. For example, being able to measure long-period waves of up to 1 hour has made it possible for seismologists to establish the overall size of great earthquakes accurately. With the old instruments, wave amplitudes were measured over only a short period range, leading to underestimates of the magnitude of great earthquakes (Fig. 1). The monitoring of longperiod waves, combined with rigorous use of wave theory, rectified this problem, and, as a result, our perception of global seismicity changed drastically during the twentieth century. With the old estimates, global seismic activity seemed to have been relatively constant over the century, but according to the new estimates, a burst of activity occurred between 1952 and 1965; about 40% of the total seismic energy released during the century was released during this period (see ref. 1 for a review).Another important finding is that most earthquakes involve a relatively low stress change, 1-10 MPa. This contrasts with the much higher stress -100 MPa or greater -involved in fracture of rocks at high confining pressure. This indicates that the fracture process in Earth's crust involves special physics, and this is currently the subject of extensive research.A better understanding of great earthquakes has also contributed to an improved understanding of the relationship between earthquakes and global plate motion.

show abstract

“…A good example of this post-earthquake information is ShakeMap (http://earthquake.usgs. gov/eqcenter/shakemap) 11 .…”

Section: Real-time Seismology and Earthquake Early Warningmentioning

confidence: 99%

Earthquake physics and real-time seismology

Kanamori

2008

Nature

Self Cite

View full text Add to dashboard Cite

show abstract

“…T max Attenuation relations describe how the amplitude of seismic waves decrease with distance and earthquake magnitude, and are commonly used to describe peak ground acceleration or velocity for large magnitude events (Campbell, 1981;Joyner and Boore, 1981;Abrahamson and Silva, 1997;Boore et al, 1997;Campbell, 1997;Fukushima and Irikura, 1997;Sadigh et al, 1997;Wald et al, 1999;Field, 2000). We determine our attenuation relations based on the P-wave amplitude and in order to calculate hypocentral distance.…”

mentioning

confidence: 99%

Single-Station Earthquake Characterization for Early Warning

Lockman

Allen

2005

Bulletin of the Seismological Society of America

View full text Add to dashboard Cite

We use data from 50 earthquakes in southern California to test the accuracy of event parameter determination using single seismic stations for the purpose of early warning. Earthquake magnitude, hypocentral distance, and backazimuth are all estimated using P-wave arrivals only. There is a wide range in the accuracy of event parameters determined by different seismic stations. One quarter of the stations produced magnitude estimates with errors less than ‫3.0ע‬ magnitude units, hypocentral distances within ‫51ע‬ km, and backazimuth calculations within ‫02ע‬Њ. This accuracy is sufficient to provide useful early warning. Using P-wave arrivals is the most rapid method of delivering earthquake early warning and may permit a few seconds notice of impending ground motion even in the epicentral region. Our results show that networks using a P-wave detection approach for early warning can increase the accuracy of magnitude estimations by determining station-specific scaling relations between the predominant period of the P wave and event magnitude and by utilizing stations with optimal relations. Further, because individual stations are able to deliver an accurate early warning, the option of utilizing the technology in regions that lack a dense seismic network but are in need of seismic hazard mitigation becomes possible.

show abstract

“…Knowing rupture extent within seconds, however, can also help to quickly identify causative faults and predict future aftershock activity in the smaller magnitude earthquakes. FinDer output might be also useful for rapid response tools, such as ShakeMap (Wald et al 1999). For example in the South Napa earthquake, the USGS released a first ShakeMap within a few minutes from the event origin.…”

Section: Discussionmentioning

confidence: 99%

FinDer v.2: Improved real-time ground-motion predictions for M2–M9 with seismic finite-source characterization

Böse¹,

Smith

Felizardo

et al. 2017

Geophysical Journal International

View full text Add to dashboard Cite

S U M M A R YRecent studies suggest that small and large earthquakes nucleate similarly, and that they often have indistinguishable seismic waveform onsets. The characterization of earthquakes in real time, such as for earthquake early warning, therefore requires a flexible modeling approach that allows a small earthquake to become large as fault rupture evolves over time. Here, we present a modeling approach that generates a set of output parameters and uncertainty estimates that are consistent with both small/moderate (≤M6.5) and large earthquakes (>M6.5) as is required for a robust parameter interpretation and shaking forecast. Our approach treats earthquakes over the entire range of magnitudes (>M2) as finite line-source ruptures, with the dimensions of small earthquakes being very small (<100 m) and those of large earthquakes exceeding several tens to hundreds of kilometres in length. The extent of the assumed line source is estimated from the level and distribution of high-frequency peak acceleration amplitudes observed in a local seismic network. High-frequency motions are well suited for this approach, because they are mainly controlled by the distance to the rupturing fault. Observed ground-motion patterns are compared with theoretical templates modeled from empirical ground-motion prediction equations to determine the best line source and uncertainties. Our algorithm extends earlier work by Böse et al. for large finite-fault ruptures. This paper gives a detailed summary of the new algorithm and its offline performance for the 2016 M7.0 Kumamoto, Japan and 2014 M6.0 South Napa, California earthquakes, as well as its performance for about 100 real-time detected local earthquakes (2.2 ≤ M ≤ 5.1) in California. For most events, both the rupture length and the strike are well constrained within a few seconds (<10 s) of the event origin. In large earthquakes, this could allow for providing warnings of up to several tens of seconds. The algorithm could also be useful for resolving fault plane ambiguities of focal mechanisms and identification of rupturing faults for earthquakes as small as M2.5.

show abstract

TriNet “ShakeMaps”: Rapid Generation of Peak Ground Motion and Intensity Maps for Earthquakes in Southern California

Cited by 537 publications

References 0 publications

Earthquake physics and real-time seismology

Earthquake physics and real-time seismology

Single-Station Earthquake Characterization for Early Warning

FinDer v.2: Improved real-time ground-motion predictions for M2–M9 with seismic finite-source characterization

Contact Info

Product

Resources

About