Eric Sandvol

Eric Sandvol
University of Missouri | Mizzou

About

256
Publications
36,961
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8,327
Citations
Citations since 2017
38 Research Items
2849 Citations
20172018201920202021202220230100200300400500
20172018201920202021202220230100200300400500
20172018201920202021202220230100200300400500
20172018201920202021202220230100200300400500

Publications

Publications (256)
Article
Full-text available
High-frequency seismic wave blockage is often the result of strong attenuation, and the regional phase Sn is particularly prone to blockage in comparison with any of the other regional phases including Lg. As widespread blockage can lead to difficulty in the estimation of source parameters or path attenuation, accurate characterization of efficient...
Preprint
Full-text available
The Thai Meteorological Department (TMD) seismic network began development in 2008. Currently there are a total of 71 seismic stations consisting of 26 borehole stations and 45 surface stations currently installed. The three-component data from the TMD seismic network have been widely used in a number of seismological studies. In a recent analysis,...
Article
Full-text available
The Turkish-Iranian Plateau and the Zagros highlands are among the most prominent physiographic features in the Middle East and were formed as a result of continental collision between the Arabian and Eurasian plates. To better understand the nature of the lithospheric mantle and the origin of the observed seismic anomalies in this region, we inves...
Article
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Plain Language Summary The subducting African Plate in the easternmost Mediterranean has been tearing beneath central Turkey as the region switches from subduction to collision. This area provides one of the best chances to study how tearing of a subducting plate impacts patterns of mantle flow during the last stages of subduction. We study mantle...
Article
We have formulated a two-dimensional Sn attenuation tomographic model to investigate the uppermost mantle shear wave Q and its tectonic implications beneath southeastern Tibet near Namche Barwa. To achieve our objective, we first compute inter-station Q values using the Two Station Method (TSM) analysis on 618 station pairs obtained from 26 regiona...
Article
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We generated high-resolution 3D seismic velocity models as well as a relocated earthquake catalog across the eastern Greater Caucasus and Kura basins. This work was done using data from the recently upgraded Republic Seismological Survey Center's (RSSC) seismic network. We generated our tomographic images of crustal velocity structure in Azerbaijan...
Article
Phase velocities at periods of 20–143 s are inverted from Rayleigh surface waves recorded at 201 stations of permanent and temporary seismic network deployed in the northern Ordos Block. We obtained the shear-wave velocities in the upper mantle from phase velocities. Our velocity models clearly reveal a striking low-velocity anomaly zone in the upp...
Article
Full-text available
We constructed a detailed map of the uppermost mantle seismic structure beneath the Central and Eastern United States (CEUS) using the International Seismological Centre Bulletin and seismic waveforms from USArray. Identical Pn and Sn travel time data sets were inverted to tomographically image the uppermost mantle P wave (Pn) velocity, S wave (Sn)...
Article
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We have constructed a 3-D shear-wave velocity (Vs) model for the crust and uppermost mantle beneath the Middle East using Rayleigh wave records obtained from ambient-noise cross-correlations and regional earthquakes. We combined one decade of data collected from 852 permanent and temporary broadband stations in the region to calculate group-velocit...
Article
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The tectonic setting of the lithosphere and upper mantle underneath Thailand varies and changes substantially over short distances. We have mapped these variations using shear wave splitting (SWS) analysis. We have determined the shear wave splitting fast polarization azimuth (Φ) and delay time (δt) using the grid search method with the assumption...
Article
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We present new high-resolution Pn velocity and anisotropy models beneath Mongolia and the adjacent regions by inverting 169,406 Pn arrivals. The data are selected from 786 permanent stations and 106 portable seismographs recently deployed in Mongolia and China's Inner Mongolia. The availability of new data acquired has allowed us to explore the upp...
Article
Using Pn-wave traveltimes from three regional distance ranges we generated Pn tomography models to investigate the 3-D nature of the uppermost mantle lid P-wave velocity structure beneath the Tibetan Plateau and surrounding regions. Significant velocity variations spatially and with depth are observed. High-velocity regions are found beneath the Hi...
Article
Full-text available
We estimated the site amplification of regional high-frequency Lg seismic phases by a reverse two-station (RTS) method using seismic events (M w 4-6) recorded by Earthscope's Transportable Array from 2010 to 2013. We compare regional site amplification estimates (horizontal and vertical) from the RTS technique with horizontal-to-vertical spectral r...
Article
We studied the crustal structure and tectonics in the north Tibetan Plateau from the Songpan-Ganzi terrane to the Qaidam Basin using teleseismic receiver-function imaging, across a major lithospheric boundary, the Kunlun-Qaidam boundary, where previous studies suggest a ~15–20-km change in crustal thickness from thicker crust in the Kunlun Mountain...
Article
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We use a very large seismic data set to provide a comprehensive image of the mantle transition zone (MTZ) beneath the Middle East. We utilized the technique of Common Conversion Point (CCP) stacking of P‐wave receiver functions to investigate the topography on the 410‐km and 660‐km discontinuities defining the upper and lower boundaries of the MTZ....
Article
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Using finite-frequency teleseismic P-wave tomography, we developed a new three-dimensional (3-D) velocity model of the mantle beneath Anatolia down to 900 km depth that reveals the structure and behavior of the subducting African lithosphere beneath three convergent domains of Anatolia: the Aegean, Cyprean, and Bitlis-Zagros domains. The Aegean sla...
Article
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Lg attenuation and site responses in Northeast (NE) China are estimated by implementing the Reverse Two Station Method (RTSM) at narrow band central frequencies of 0.5, 1.0, 2.0 and 3.0 Hz using 453 earthquakes recorded by 201 seismic stations deployed in the region from 1995 to 2013. The RTSM has the advantage of removing source and site effects w...
Article
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We present tomographic models of frequency-dependent Lg and Sn attenuation in eastern Mongolia using data from 228 local earthquakes that were recorded by 69 broad-band seismic stations. We adopt the two-station method (TSM) and reverse two-station method (RTM) to measure the frequency-dependent Sn and Lg Q values, respectively. The RTM has the adv...
Article
Full-text available
The central Anatolian plateau in Turkey is a region with a long history of subduction, continental collision, accretion of continental fragments, and slab tearing and/or breakoffand tectonic escape. Central Anatolia is currently characterized as a nascent plateau with widespread Neogene volcanism and predominantly transtensional deformation. To elu...
Article
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Subduction beneath central Anatolia represents the transition between continuous subduction along the Aegean trench in the west and slab break-off and/or subduction termination at the Arabian-Eurasian collision zone in the east. Using recently collected seismic data from the Continental Dynamics-Central Anatolian Tectonics project alongside a newly...
Article
Recent studies have shown that Paleoproterozoic rocks, called the Khondalite Belt, crop out along a nearly EW-trending zone in the northern edge of the Ordos block, North China. This widely distributed Khondalite rock suggests that they originated in the margin of a passive continent during the Paleoproterozoic Era. Seismic stations deployed in the...
Conference Paper
A Paleoproterozoic collision zone has been found in the northern Ordos block, North China. Seismic stations deployed in the northern Ordos block and its adjacent regions provide a plenty of information about crustal thickness and Vp/Vs ratio, determined by use of receiver function H-κ stacking. The H-κ stacked images show an approximately EW-trendi...
Conference Paper
Full-text available
Despite significant progress toward understanding the kinematics of modern tectonic escape in Anatolia, considerable uncertainty remains regarding the dynamics of the transition from collision to escape. Because of the relatively small size of the Anatolia microplate, regional-scale studies spanning the plate margins and interior are well-suited to...
Conference Paper
Magnetotelluric (MT) data were collected to examine the electrical resistivity structure of a metamorphic core complex known as the Ni˘ gde Massif and a northeast-southwest aligned fault zone (Central Anatolian Fault Zone, CAFZ) bounding this massif on the east in Central Anatolia. The Nigde Massif is a crystalline dome close to Inner-Tauride Sutur...
Conference Paper
Wide-band magnetotelluric (MT) (360 Hz – 1860 sec) data were acquired at 25 sites along a north – south aligned profile cutting across the Central Pontides, which are made up of highly metamorphosed formations and their tectonic boundaries including: a Lower Cretaceous-aged turbidite sequence, Central Pontides Metamorphic Super-complex (CPMS), Nort...
Conference Paper
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Hasandağ stratovolcano is one of the most devastating volcanic edifices in the Central Anatolia, Turkey. The volcano has been studied for decades but there is still no consensus on its origin. To provide new insight on Hasandağ, there is also a need for geophysical explorations (e.g. seismology, magnetotelluric-MT) within the region. As a part of c...
Article
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Reliable moment magnitude estimates for seismic events in the Middle East region can be difficult to obtain due to the uneven distribution of stations, the complex tectonic structure, and regions of high attenuation. In this study, we take advantage of the many new broadband seismic stations that have become available through improved national netw...
Conference Paper
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At the northern boundary of the Wind River basin, the Stagner Creek fault is one of several ENE-WSW striking Quaternary faults in central Wyoming. In order to understand the structural context of this fault, this study combines a reassessment of the morphology of the Stagner Creek scarp along with an initial view of its shallow subsurface structure...
Article
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The crustal thickness H and average crustal velocity ratio k (Vp/Vs) beneath south central Mongolia are investigated using the H-k stacking method based on teleseismic radial receiver functions. Our primary results reveal that the local crustal thickness varies from 38 to 46km with an average value of 43km. Thicker crust is found beneath the wester...
Article
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Three models were used to produce three probabilistic hazard maps for the Jordan-Dead Sea transform ͑DST͒. No seismic source zones were proposed. Models I and II are based on spatially smoothed historical and instrumentally recorded earthquakes. Model I used the data with magnitudes greater than 3.0 for the time period 1900 to 2003, while Model II...
Conference Paper
The Stagner Creek Fault, near the southern margin of the Owl Creek Mountains is one of a handful of WNW-ESE striking faults in central Wyoming that exhibit quaternary activity. These faults are generally believed to be normal faults, but the geometry and kinematic behavior of the Stagner Creek Fault is not well defined – a previous shallow seismic...
Conference Paper
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Isparta Angle (IA) constitutes a triangular shape elevated tectonic domain in SW Turkey which contains units stacked with opposing thrust vergences during Late Cretaceous to Miocene. The region which is located at the junction between Aegean and Cyprus arcs separated by a slab tear is now bounded by Fethiye-Burdur Fault Zone (FBFZ) in the west and...
Conference Paper
Three magnetotelluric (MT) profiles were constructed to examine the electrical resistivity strucuture of a metamorphic core complex renown as Niğde massif and a northeast - southwest aligned fault zone (Central Anatolian Fault Zone, CAFZ) bounding this massif on the east in Central Anatolia. Nigde massif is a crystalline dome close to Inner-Tauride...
Article
Full-text available
We present a new approach for understanding the origin and nature of seismic anomalies in the continental crust of the Northern Middle East. We have created detailed attenuation (QLg) and velocity (VLg) models for the Northern Middle East based on the analysis of waveforms of regional seismic phase Lg from 3171 regional earthquakes recorded at 578...
Article
The stable Ordos Plateau, extensional Weihe Graben, and Qinling orogenic belt are located at the northeast margin of the Tibetan Plateau. They have been thought to play different roles in the eastward expanding of the Tibetan Plateau. Peking University deployed a linear seismic array across the western end of the Weihe Graben to investigate the cru...
Conference Paper
Full-text available
The S tagner Creek fault, along the southern margin of the Owl Creek Mountains, is one of several east-west striking Quaternary faults that occur in central Wyoming. These Quaternary faults are enigmatic in that they strike nearly orthogonal to the eas tern Basin and Range faults observed in western Wyoming. These east-west striking faults are infe...
Article
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The 127 station NorthEast China Extended SeiSmic Array (NECESSArray) provides large quantities of high quality seismic data in northeast China that allow us to resolve lateral variations of Lg Q or crustal attenuation at 1 Hz (Qo) to 2.0° or greater. Using the reverse two-station/event method with 11 642 Lg path-amplitudes from 78 crustal earthquak...
Article
Lg waveforms recorded by EarthScope's Transportable Array (TA) are used to estimate Lg Q(0) in the central and eastern United States (CEUS). Attenuation is calculated based on Lg spectral amplitudes filtered at a narrow band from 0.5 to 1.5 Hz. Two-station and reverse two-station techniques are used to calculate Q(0) values. 39 events occurring fro...
Article
We use fundamental mode Rayleigh waves recorded at 45 temporary and permanent broadband seismic stations in the Ordos block, and invert for average phase velocities and azimuthal anisotropy of the 12 periods from 20 to 143 s by the two-plane-wave inversion technique. And one-dimensional shear wave velocity model is inverted from phase velocities. T...
Article
Full-text available
We have investigated the seismic anisotropy beneath the Central Andean southern Puna plateau by applying shear wave splitting analysis and shear wave splitting tomography to local S waves and teleseismic SKS, SKKS and PKS phases. Overall, a very complex pattern of fast directions throughout the southern Puna plateau region and a circular pattern of...
Article
Earthquake hypocenters recorded in the Andean Southern Puna seismic array (25-28°S; 70-65°W) provide new constraints on the shape of the subducting Nazca plate beneath the Puna plateau, the transition into the Chilean-Pampean flatslab and the thermal state of the mantle and crust. Some 270 new mantle hypocenters suggest that the subducting slab und...
Article
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Broadband seismic data from the regional seismic network operated by the China Earthquake Administration and 32 temporary seismic stations are used to image the crustal velocity structure in the northeast Tibetan plateau. Empirical Rayleigh- and Love-wave Green’s functions are obtained from interstation cross correlation of continuous seismic recor...
Article
[1] Geodynamic processes occurring in the upper mantle such as slab break off and lithosphere delamination often result in high rates of lithospheric deformation and rapid tectonic uplift of large areas. The continent-continent collision zone between Arabia and Eurasia has been widely studied in this context but several different viable geodynamic...
Article
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We collected continuous seismic data recorded between 2007-2010 by 208 broadband stations from the Chinese Provincial Digital Seismic Networks, A Seismic Collaborative Experiment of Northern Tibet (ASCENT), and the NorthEastern Tibet Seismic experiment (NETS). Cross-correlations of vertical-component records are computed to extract Rayleigh wave em...
Article
Full-text available
The northeastern margin of the Tibetan Plateau, which includes the Qiangtang and Songpan-Ganzi terranes as well as the Kunlun Shan and the Qaidam Basin, continues to deform in response to the ongoing India–Eurasia collision. To test competing hypotheses concerning the mechanisms for this deformation, we assembled a high-quality data set of approxim...
Article
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Crustal thicknesses and Poissonʼs ratios in the Ordos block and surrounding regions were estimated by the use of the H–kH–k stacking method on teleseismic receiver functions. The data came from 353 temporary and permanent seismic stations in 2006–2011. Results show that the crustal thickness and Poissonʼs ratio gently vary within the Ordos block, w...
Article
[1] The southern Puna Plateau has been proposed to result from a major Pliocene delamination event that has previously been inferred from geochemical, geological and some preliminary geophysical data. 75 seismic stations were deployed across the southern Puna Plateau in 2007-2009 by scientists from the USA, Germany, Chile and Argentina to test the...
Article
The high elevation of the southern Puna plateau, the widespread melting of its crust, the gap in intermediate depth seismicity and the recent eruptions of ignimbrite complexes can be explained by delamination of the lithospheric mantle beneath it. To test this hypothesis, an array consisting of 73 broad band and short period seismic stations was de...
Article
Full-text available
The northeastern Tibetan Plateau has undergone active shortening due to the India-Asia collision and has been an ideal place for studying the growth of the plateau. To reveal deep structure that is responsible for geological observations in NE Tibet, we have constructed a 3-D shear wave velocity model from Rayleigh waves recorded by 36 stations in...
Article
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The central Andes is the type locality for magmas erupted through thickened crust in a continental margin arc. A compilation of some 600 chemical analyses shows that 25-0 Ma andesites erupted in the southern Central Volcanic Zone region (25.5- 28.2°S) north of the Chilean flatslab exhibit among the greatest range of trace element and isotopic ratio...
Article
1] We use ambient-noise tomography to map regional differences in crustal Rayleigh-wave group velocities with periods of 8–40 s across north Tibet using the International Deep Profiling of Tibet and the Himalaya phase IV arrays (132 stations, deployed for 10–24 months). For periods of 8–24 s (sensitive to midcrustal depths of ~5–30 km), we observe...
Article
We estimate Lg wave attenuation using local and regional seismic phases in the Isparta Angle and the Anatolian Plateau (Turkey). The Isparta Angle (IA) is a tectonically active zone forming the boundary between the African Plate and the Anatolian Plateau, and is currently undergoing N–S extensional deformation. The Anatolian Plateau contains many i...
Article
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Data from recent INDEPTH IV and other broadband deployments in Tibet are used to invert for crustal delays and Pn velocities beneath the eastern Tibetan Plateau and surrounding regions. The average Pn velocity for the region is 8.1 km/s but varies from 7.8 to over 8.3 km/s. Generally low Pn velocities are found in the northeastern Tibet in the Qian...
Article
Abstract We performed a teleseismic P wave tomography study using seismic events at both teleseismic and regional distances, recorded by a temporary seismic array in the Argentine Puna Plateau and adjacent regions. The tomographic images show the presence of a number of positive and negative anomalies in a depth range of 20–300 km beneath the array...
Article
Using fundamental mode Rayleigh waves from the INDEPTH-IV and Namche-Barwa seismic experiments for periods between 20 and 143 s, we have investigated the lithospheric structure beneath eastern Tibet. We have found a ˜200-km-wide high velocity body, starting at ˜60 km depth and roughly centered beneath the Bangong-Nijuang Suture, which is most likel...
Article
Full-text available
The Q of seismic phase Lg is measured to approach the crustal Qβ, which can be used to infer crustal rheology. A reverse two-station/event method is used to measure the interstationQLg, which theoretically eliminates effects from the source and site response. Strong azimuthal anisotropy of 1/QLg in northern Tibet is observed, which approximately co...