Improving Sparse Network Seismic Location with Bayesian Kriging and Teleseismically Constrained Calibration Events

Myers, Stephen C.; Schultz, Craig A.

doi:10.1785/0119980171

Cited by 58 publications

(69 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results are consistent with those of Myers and Schultz (2000), who showed that the mislocations are due to the need for travel-time corrections as large as 3 seconds at some stations.…”

Section: Examples Of Confidence Regionssupporting

confidence: 92%

“…Figure 1 shows confidence regions computed for two events from the 1991 Racha, Georgia, earthquake sequence, studied by Myers and Schultz (2000). The data sets comprise P wave arrival times from 5 or 6 regional stations, shape.…”

Section: Examples Of Confidence Regionsmentioning

confidence: 99%

“…91135030) from the 1991 Racha, Georgia earthquake sequence, studied by Myers and Schultz (2000). The data set comprised P wave arrival times from 6 stations, obtained from ISC and supplemented with picks made by F. Ryall of LLNL.…”

Section: Examplesmentioning

confidence: 99%

See 2 more Smart Citations

Grid-Search Techniques for Seismic Event Location and Phase Association

Toksöz¹,

Rodi²,

Sarkar³

2007

View full text Add to dashboard Cite

REPORT DOCUMENTATION PAGEOMB maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services. Directorate for Information , 1215 Jefferson Davis Highway, Suite 1204. Arlington, VA 22202-4302. Respondents shoutd be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM-YYYY)2. REPORT 14. ABSTRACTThe objectives of this project are to develop improved methods for locating seismic events and to develop new approaches to analyzing the seismic event location uncertainty. Our efforts are focused on the problems of both single and multiple event location. For a single event, we have formulated a statistical approach based on maximum-likelihood estimation and implemented it with grid-search and Monte Carlo techniques to yield an algorithm called "Grid-Search Single Event Location" (GSEL), which computes non-elliptical confidence regions on event locations for a wide class of assumed probability distributions (Gaussian and non-Gaussian) and for data picking errors. We have applied GSEL to regional arrival data from the 1991 Racha earthquake sequence and from the 1998 Adana (Turkey) earthquake sequence. Our multiple-event grid-search location algorithm (called GMEL) is also based on a maximum likelihood formulation of the location problem and it solves jointly for the location parameters (hypocenters and origin times) of seismic events in a cluster and travel-time corrections at the stations recording the events, GMEL accommodates non-Gaussian as well as Gaussian models of picking errors. We test this GMEL with clusters of 1999 Izmit/Duzce (Turkey) earthquake sequence. The approach we developed is based on the maximumlikelihood framework determines confidence regions on event locations under a general class of picking error models (Gaussian and nonGaussian). For a single event, we have formulated a statistical approach based on maximumlikelihood estimation and implemented it with grid-search and Monte Carlo techniques to yield an algorithm called "Grid-Search Single Event Location" (GSEL), which computes non-elliptical confidence regions on event locations for a wide class of assumed probability distributions (Gaussian and non-Gaussian), and for data picking errors. We have applied GSEL to regional arrival data from the 1991 Racha earthquake sequenceand from the 1998 Adana (Turkey) earthquake sequence.Our multiple-event grid search location algorithm (called GMEL) is also based on a maximum-likelihood formulation of the location problem and it solves jointly for the location parameters (hypocenters and origin times) of seismic events in a cluster and travel-time cor...

show abstract

Section: Examples Of Confidence Regionssupporting

confidence: 92%

Section: Examples Of Confidence Regionsmentioning

confidence: 99%

See 1 more Smart Citation

Grid-Search Techniques for Seismic Event Location and Phase Association

Toksöz¹,

Rodi²,

Sarkar³

2007

View full text Add to dashboard Cite

show abstract

“…In the case of corrections to account for unmodeled velocity structure, interpolation of empirical traveltime observations may be used to improve prediction accuracy and characterize uncertainty (e.g. Figure 1; Myers and Schultz, 2000). This approach works well where empirical observations are available and has proved robust in operational systems.…”

Section: Global Travel Timesmentioning

confidence: 99%

The Prospect of using Three-Dimensional Earth Models To Improve Nuclear Explosion Monitoring and Ground Motion Hazard Assessment

Antoun¹,

Harris²,

Lay³

et al. 2008

View full text Add to dashboard Cite

SummaryThe last ten years have brought rapid growth in the development and use of threedimensional (3D) seismic models of earth structure at crustal, regional and global scales. In order to explore the potential for 3D seismic models to contribute to important societal applications, Lawrence Livermore National Laboratory (LLNL) hosted a "Workshop on Multi-Resolution 3D Earth Models to Predict Key Observables in Seismic Monitoring and Related Fields" on June 6 and 7, 2007 in Berkeley, California. The workshop brought together academic, government and industry leaders in the research programs developing 3D seismic models and methods for the nuclear explosion monitoring and seismic ground motion hazard communities. The workshop was designed to assess the current state of work in 3D seismology and to discuss a path forward for determining if and how 3D earth models and techniques can be used to achieve measurable increases in our capabilities for monitoring underground nuclear explosions and characterizing seismic ground motion hazards. This paper highlights some of the presentations, issues, and discussions at the workshop and proposes a path by which to begin quantifying the potential contribution of progressively refined 3D seismic models in critical applied arenas.

show abstract

“…Travel-time residuals for the GT events are calculated relative to a velocity model and then these calibration points are statistically interpolated to form continuous travel-time correction surfaces (Schultz et al 1998;Myers & Schultz 2000). Myers & Schultz (2000) demonstrated that applying such empirical corrections significantly reduces the bias in location and improve the ability to locate the lower magnitude events. In another technique, the travel-time corrections can be refined by determining a set of station corrections.…”

Section: Introductionmentioning

confidence: 99%

Revision of earthquake hypocentre locations in global bulletin data sets using source-specific station terms

Nooshiri

Saul²,

Heimann³

et al. 2016

Geophys. J. Int.

View full text Add to dashboard Cite

S U M M A R YGlobal earthquake locations are often associated with very large systematic travel-time residuals even for clear arrivals, especially for regional and near-regional stations in subduction zones because of their strongly heterogeneous velocity structure. Travel-time corrections can drastically reduce travel-time residuals at regional stations and, in consequence, improve the relative location accuracy. We have extended the shrinking-box source-specific station terms technique to regional and teleseismic distances and adopted the algorithm for probabilistic, nonlinear, global-search location. We evaluated the potential of the method to compute precise relative hypocentre locations on a global scale. The method has been applied to two specific test regions using existing P-and pP-phase picks. The first data set consists of 3103 events along the Chilean margin and the second one comprises 1680 earthquakes in the Tonga-Fiji subduction zone. Pick data were obtained from the GEOFON earthquake bulletin, produced using data from all available, global station networks. A set of timing corrections varying as a function of source position was calculated for each seismic station. In this way, we could correct the systematic errors introduced into the locations by the inaccuracies in the assumed velocity structure without explicitly solving for a velocity model. Residual statistics show that the median absolute deviation of the travel-time residuals is reduced by 40-60 per cent at regional distances, where the velocity anomalies are strong. Moreover, the spread of the travel-time residuals decreased by ∼20 per cent at teleseismic distances (>28 • ). Furthermore, strong variations in initial residuals as a function of recording distance are smoothed out in the final residuals. The relocated catalogues exhibit less scattered locations in depth and sharper images of the seismicity associated with the subducting slabs. Comparison with a high-resolution local catalogue reveals that our relocation process significantly improves the hypocentre locations compared to standard locations.

show abstract

Improving Sparse Network Seismic Location with Bayesian Kriging and Teleseismically Constrained Calibration Events

Cited by 58 publications

References 19 publications

Grid-Search Techniques for Seismic Event Location and Phase Association

Grid-Search Techniques for Seismic Event Location and Phase Association

The Prospect of using Three-Dimensional Earth Models To Improve Nuclear Explosion Monitoring and Ground Motion Hazard Assessment

Revision of earthquake hypocentre locations in global bulletin data sets using source-specific station terms

Contact Info

Product

Resources

About