User's manual for SIMULPS12 for imaging vp and vp/vs; a derivative of the "Thurber" tomographic inversion SIMUL3 for local earthquakes and explosions

Evans, John R.; Eberhart‐Phillips, Donna; Thurber, C. H.

doi:10.3133/ofr94431

Cited by 237 publications

(196 citation statements)

References 10 publications

(8 reference statements)

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“…The resolution and covariance matrices are calculated in order to estimate the resolution of the model and the uncertainties in the model parameters. An advantage of the simul2000 algorithm is that the ray tracing is done with regard to station elevation so that the effect of topography can be taken into account [Evans et al, 1994]. It has been shown that a layer of unmodeled nodes a short distance above the highest-elevation stations is helpful in situations with large topographic relief and shallow earthquakes [Dawson et al, 1992].…”

Section: Tomographic Inversion Approachmentioning

confidence: 99%

Three‐dimensional seismic velocity structure of Mauna Loa and Kilauea volcanoes in Hawaii from local seismic tomography

et al. 2014

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We present a new three‐dimensional seismic velocity model of the crustal and upper mantle structure for Mauna Loa and Kilauea volcanoes in Hawaii. Our model is derived from the first‐arrival times of the compressional and shear waves from about 53,000 events on and near the Island of Hawaii between 1992 and 2009 recorded by the Hawaiian Volcano Observatory stations. The Vp model generally agrees with previous studies, showing high‐velocity anomalies near the calderas and rift zones and low‐velocity anomalies in the fault systems. The most significant difference from previous models is in Vp/Vs structure. The high‐Vp and high‐Vp/Vs anomalies below Mauna Loa caldera are interpreted as mafic magmatic cumulates. The observed low‐Vp and high‐Vp/Vs bodies in the Kaoiki seismic zone between 5 and 15 km depth are attributed to the underlying volcaniclastic sediments. The high‐Vp and moderate‐ to low‐Vp/Vs anomalies beneath Kilauea caldera can be explained by a combination of different mafic compositions, likely to be olivine‐rich gabbro and dunite. The systematically low‐Vp and low‐Vp/Vs bodies in the southeast flank of Kilauea may be caused by the presence of volatiles. Another difference between this study and previous ones is the improved Vp model resolution in deeper layers, owing to the inclusion of events with large epicentral distances. The new velocity model is used to relocate the seismicity of Mauna Loa and Kilauea for improved absolute locations and ultimately to develop a high‐precision earthquake catalog using waveform cross‐correlation data.

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Section: Tomographic Inversion Approachmentioning

confidence: 99%

Three‐dimensional seismic velocity structure of Mauna Loa and Kilauea volcanoes in Hawaii from local seismic tomography

et al. 2014

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“…The inversion reduces these station delays by inverting for a 3-D velocity model with a realistic model length [Evans et al, 1994]. We use the decrease in size of these station delays to demonstrate the quantitative progress of the 3-D inversion.…”

Section: Appendixmentioning

confidence: 99%

Crustal structure and seismicity distribution adjacent to the Pacific and North America plate boundary in southern California

Hauksson¹

2000

J. Geophys. Res.

268

343

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“…We apply the inversion method and computer algorithm SIMULPS developed by (Thurber, 1983) and (Eberhart-Phillips, 1990) (documentation provided by Evans et al, 1994). SIMULPS is a damped least squares, full matrix inversion method intended for use with natural local earthquakes and controlled sources.…”

Section: Local Earthquake Tomographymentioning

confidence: 99%

“…In local earthquake tomography the volume of investigation needs to be adequately sampled by a dense set of crossing rays (a function of the source-receiver distribution) to resolve the inherent trade-off between variations in velocity structure and hypocentre locations. As the data are generally only sampled at relatively few points on the Earth's surface they are typically aliased spatially and the resolution of the image is therefore limited by the distribution of rays (both in the ray path location and its direction) within the target volume (Evans et al, 1994).…”

Section: Introductionmentioning

confidence: 99%

Local earthquake tomography of Scotland

Luckett

Baptie

2015

Geophysical Journal International

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Scotland is a relatively aseismic region for the use of local earthquake tomography, but 40 years of earthquakes recorded by a good and growing network make it possible. A careful selection is made from the earthquakes located by the British Geological Survey (BGS) over the last four decades to provide a dataset maximising arrival time accuracy and ray-path coverage of Scotland. A large number of 1-D velocity models with different layer geometries are considered and differentiated by employing quarry blasts as ground-truth events. Then, SIMULPS14 is used to produce a robust 3-D tomographic P-wave velocity model for Scotland. In areas of high resolution the model shows good agreement with previously published interpretations of seismic refraction and reflection experiments. However, the model shows relatively little lateral variation in seismic velocity except at shallow depths, where sedimentary basins such as the Midland Valley are apparent. At greater depths, higher velocities in the northwest parts of the model suggest that the thickness of crust increases towards the south and east. This observation is also in agreement with previous studies. Quarry blasts used as ground truth events and relocated with the preferred 3-D model are shown to be markedly more accurate than when located with the existing BGS 1-D velocity model.

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User's manual for SIMULPS12 for imaging vp and vp/vs; a derivative of the "Thurber" tomographic inversion SIMUL3 for local earthquakes and explosions

Cited by 237 publications

References 10 publications

Three‐dimensional seismic velocity structure of Mauna Loa and Kilauea volcanoes in Hawaii from local seismic tomography

Three‐dimensional seismic velocity structure of Mauna Loa and Kilauea volcanoes in Hawaii from local seismic tomography

Crustal structure and seismicity distribution adjacent to the Pacific and North America plate boundary in southern California

Local earthquake tomography of Scotland

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