A geodetic plate motion and Global Strain Rate Model
01 Oct 2014-Geochemistry Geophysics Geosystems (John Wiley & Sons, Ltd)-Vol. 15, Iss: 10, pp 3849-3889
TL;DR: The Global Strain Rate Model (GSRM v.2.1) as mentioned in this paper is a new global model of plate motions and strain rates in plate boundary zones constrained by horizontal geodetic velocities.
Abstract: We present a new global model of plate motions and strain rates in plate boundary zones constrained by horizontal geodetic velocities. This Global Strain Rate Model (GSRM v.2.1) is a vast improvement over its predecessor both in terms of amount of data input as in an increase in spatial model resolution by factor of ∼2.5 in areas with dense data coverage. We determined 6739 velocities from time series of (mostly) continuous GPS measurements; i.e., by far the largest global velocity solution to date. We transformed 15,772 velocities from 233 (mostly) published studies onto our core solution to obtain 22,511 velocities in the same reference frame. Care is taken to not use velocities from stations (or time periods) that are affected by transient phenomena; i.e., this data set consists of velocities best representing the interseismic plate velocity. About 14% of the Earth is allowed to deform in 145,086 deforming grid cells (0.25° longitude by 0.2° latitude in dimension). The remainder of the Earth's surface is modeled as rigid spherical caps representing 50 tectonic plates. For 36 plates we present new GPS-derived angular velocities. For all the plates that can be compared with the most recent geologic plate motion model, we find that the difference in angular velocity is significant. The rigid-body rotations are used as boundary conditions in the strain rate calculations. The strain rate field is modeled using the Haines and Holt method, which uses splines to obtain an self-consistent interpolated velocity gradient tensor field, from which strain rates, vorticity rates, and expected velocities are derived. We also present expected faulting orientations in areas with significant vorticity, and update the no-net rotation reference frame associated with our global velocity gradient field. Finally, we present a global map of recurrence times for Mw=7.5 characteristic earthquakes.
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TL;DR: In this paper, the authors process GPS data from continental China to derive site velocities and find that the deformation field inside the Tibetan plateau and Tien Shan is predominantly continuous and large deformation gradients only exist perpendicular to the Indo-Eurasian relative plate motion and are associated with a few large strike slip faults.
Abstract: We process rigorously GPS data observed during the past 25 years from continental China to derive site secular velocities. Analysis of the velocity solution leads to the following results. (a) The deformation field inside the Tibetan plateau and Tien Shan is predominantly continuous, and large deformation gradients only exist perpendicular to the Indo‐Eurasian relative plate motion and are associated with a few large strike‐slip faults. (b) Lateral extrusions occur on both the east and west sides of the plateau. The westward extrusion peaks at ~6 mm/yr in the Pamir‐Hindu Kush region. A bell‐shaped eastward extrusion involves most of the plateau at a maximum rate of ~20 mm/yr between the Jiali and Ganzi‐Yushu faults, and the pattern is consistent with gravitational flow in southern and southeastern Tibet where the crust shows widespread dilatation at 10–20 nanostrain/yr. (c) The southeast borderland of Tibet rotates clockwise around the eastern Himalaya syntaxis, with sinistral and dextral shear motions along faults at the outer and inner flanks of the rotation terrane. The result suggests gravitational flow accomplished through rotation and translation of smaller subblocks in the upper crust. (d) Outside of the Tibetan plateau and Tien Shan, deformation field is block‐like. However, unnegligible internal deformation on the order of a couple of nanostrain/yr is found for all blocks. The North China block, under a unique tectonic loading environment, deforms and rotates at rates significantly higher than its northern and southern neighboring blocks, attesting its higher seismicity rate and earthquake hazard potential than its neighbors.
403 citations
Cites background or methods from "A geodetic plate motion and Global ..."
...Allmendinger et al. (2007), Zheng et al. (2017), Kreemer et al. (2014), and Rui and WANG AND SHEN 16 of 22 Stamps (2019) derived strain rates in continental China, to which our strain rate pattern shows overall similarity....
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...…Tibet, and the contrasting rotations of clockwise rotation around the EHS and counterclockwise rotation around the Xianshuihe‐Xiaojiang fault system, respectively (the latter was also revealed by Kreemer et al., 2014, based on the analysis of an early version of this velocity solution)....
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...We further incorporate several velocity solutions from previous studies (Kreemer et al., 2014 [which is a compilation of results of many other studies]; Devachandra et al., 2014; Gupta et al., 2015; Marechal et al., 2016; Vernant et al., 2014), to WANG AND SHEN 5 of 22 provide better coverage of…...
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TL;DR: GPlates as mentioned in this paper is an open-source, cross-platform plate tectonic geographic information system, enabling the interactive manipulation of plate-tectonic reconstructions and the visualization of geodata through geological time.
Abstract: GPlates is an open‐source, cross‐platform plate tectonic geographic information system, enabling the interactive manipulation of plate‐tectonic reconstructions and the visualization of geodata through geological time. GPlates allows the building of topological plate models representing the mosaic of evolving plate boundary networks through time, useful for computing plate velocity fields as surface boundary conditions for mantle convection models and for investigating physical and chemical exchanges of material between the surface and the deep Earth along tectonic plate boundaries. The ability of GPlates to visualize subsurface 3‐D scalar fields together with traditional geological surface data enables researchers to analyze their relationships through geological time in a common plate tectonic reference frame. To achieve this, a hierarchical cube map framework is used for rendering reconstructed surface raster data to support the rendering of subsurface 3‐D scalar fields using graphics‐hardware‐accelerated ray‐tracing techniques. GPlates enables the construction of plate deformation zones—regions combining extension, compression, and shearing that accommodate the relative motion between rigid blocks. Users can explore how strain rates, stretching/shortening factors, and crustal thickness evolve through space and time and interactively update the kinematics associated with deformation. Where data sets described by geometries (points, lines, or polygons) fall within deformation regions, the deformation can be applied to these geometries. Together, these tools allow users to build virtual Earth models that quantitatively describe continental assembly, fragmentation and dispersal and are interoperable with many other mapping and modeling tools, enabling applications in tectonics, geodynamics, basin evolution, orogenesis, deep Earth resource exploration, paleobiology, paleoceanography, and paleoclimate.
397 citations
Cites background from "A geodetic plate motion and Global ..."
...…gridding from seafloor age models applied (Maus et al., 2009), crustal thickness (https://igppweb. ucsd.edu/~gabi/crust2.html), crustal strain (Kreemer et al., 2014), and UNESCO global geology (https://…...
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TL;DR: In this article, the authors present details of the new WSM database release 2016 and an analysis of global and regional stress pattern, and show two examples of 40 degrees-60 degrees S-Hmax rotations within 70 km.
386 citations
TL;DR: The authors presented a global Mesozoic-Cenozoic deforming plate motion model that captures the progressive extension of all continental margins since the initiation of rifting within Pangea at ~240 Ma.
Abstract: Global deep‐time plate motion models have traditionally followed a classical rigid plate approach, even though plate deformation is known to be significant. Here we present a global Mesozoic–Cenozoic deforming plate motion model that captures the progressive extension of all continental margins since the initiation of rifting within Pangea at ~240 Ma. The model also includes major failed continental rifts and compressional deformation along collision zones. The outlines and timing of regional deformation episodes are reconstructed from a wealth of published regional tectonic models and associated geological and geophysical data. We reconstruct absolute plate motions in a mantle reference frame with a joint global inversion using hot spot tracks for the last 80 million years and minimizing global trench migration velocities and net lithospheric rotation. In our optimized model, net rotation is consistently below 0.2°/Myr, and trench migration scatter is substantially reduced. Distributed plate deformation reaches a Mesozoic peak of 30 × 10^6 km^2 in the Late Jurassic (~160–155 Ma), driven by a vast network of rift systems. After a mid‐Cretaceous drop in deformation, it reaches a high of 48 x 10^6 km^2 in the Late Eocene (~35 Ma), driven by the progressive growth of plate collisions and the formation of new rift systems. About a third of the continental crustal area has been deformed since 240 Ma, partitioned roughly into 65% extension and 35% compression. This community plate model provides a framework for building detailed regional deforming plate networks and form a constraint for models of basin evolution and the plate‐mantle system.
305 citations
Cites background or methods from "A geodetic plate motion and Global ..."
...This value is significantly smaller than Kreemer et al.'s (2014) estimate of 14%. The reason for the discrepancy is that we solely focus on deformation of continental lithosphere. Therefore, our model excludes large deforming regions in ocean basins, particularly in the Indian Ocean. Our model also excludes deforming edges of overriding plates along subduction zones, which form another significant portion of Kreemer et al.'s (2014) geodetic strain‐rate model....
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...A combination of GPS, geological, and seismic observations together with a global model of rigid plate motions has been used to obtain a continuous field of present‐day plate deformation (Kreemer et al., 2003, 2014)....
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...They built a present‐day deforming plate model and estimated that about 15% of Earth's surface area today is deforming along diffuse deformation zones; this was later revised to 14% (Kreemer et al., 2014)....
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...This value is significantly smaller than Kreemer et al.'s (2014) estimate of 14%....
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TL;DR: In this paper, the authors present the most complete, accurate, and up-to-date velocity field for India-Eurasia available, comprising 2576 velocities measured during 1991-2015.
Abstract: The India‐Eurasia collision zone is the largest deforming region on the planet; direct measurements of present‐day deformation from Global Positioning System (GPS) have the potential to discriminate between competing models of continental tectonics. But the increasing spatial resolution and accuracy of observations have only led to increasingly complex realizations of competing models. Here we present the most complete, accurate, and up‐to‐date velocity field for India‐Eurasia available, comprising 2576 velocities measured during 1991–2015. The core of our velocity field is from the Crustal Movement Observation Network of China‐I/II: 27 continuous stations observed since 1999; 56 campaign stations observed annually during 1998–2007; 1000 campaign stations observed in 1999, 2001, 2004, and 2007; 260 continuous stations operating since late 2010; and 2000 campaign stations observed in 2009, 2011, 2013, and 2015. We process these data and combine the solutions in a consistent reference frame with stations from the Global Strain Rate Model compilation, then invert for continuous velocity and strain rate fields. We update geodetic slip rates for the major faults (some vary along strike), and find that those along the major Tibetan strike‐slip faults are in good agreement with recent geological estimates. The velocity field shows several large undeforming areas, strain focused around some major faults, areas of diffuse strain, and dilation of the high plateau. We suggest that a new generation of dynamic models incorporating strength variations and strain‐weakening mechanisms is required to explain the key observations. Seismic hazard in much of the region is elevated, not just near the major faults.
246 citations
Cites background or methods from "A geodetic plate motion and Global ..."
...The velocities are then transformed into the Eurasia-fixed frame according to the IGS08-Eurasia Euler vector given by Kreemer et al. (2014) (wx = 0.0247, wy = 0.1418, wz = 0.2093°/Myr)....
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...Note that such conversion only results in changes of less than 0.7 mm/yr for the stations in Kreemer et al. (2014)....
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...We processed all the GPS data collected via the CMONOC-I/II projects up to the end of 2015 and combined these results with the GPS velocities outside the CMONOC-I/II projects presented in Kreemer et al. (2014)....
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...We present the most complete, accurate, and up-to-date interseismic GPS velocity field for the India-Eurasia collision zone by combining 1556 stations from the CMONOC-I/II projects with 1020 stations compiled by Kreemer et al. (2014)....
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...Using the 1078 common stations observed at least three epochs, we calculate an Euler vector (wx = 0.0015, wy = 0.0049, wz = 0.0030°/Myr) and then apply it to convert the 1020 uncommon stations observed from 1991 to 2013 in Kreemer et al. (2014) into our solution....
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References
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TL;DR: A global plate motion model, named NUVEL-1, which describes current plate motions between 12 rigid plates is described, with special attention given to the method, data, and assumptions used as discussed by the authors.
Abstract: A global plate motion model, named NUVEL-1, which describes current plate motions between 12 rigid plates is described, with special attention given to the method, data, and assumptions used Tectonic implications of the patterns that emerged from the results are discussed It is shown that wide plate boundary zones can form not only within the continental lithosphere but also within the oceanic lithosphere; eg, between the Indian and Australian plates and between the North American and South American plates Results of the model also suggest small but significant diffuse deformation of the oceanic lithosphere, which may be confined to small awkwardly shaped salients of major plates
3,409 citations
TL;DR: In this article, the optimal recalibration of NUVEL-1 is proposed to multiply the angular velocities by a constant, α, of 0.9562, which is a compromise among slightly different calibrations appropriate for slow, medium, and fast rates of seafloor spreading.
Abstract: Recent revisions to the geomagnetic time scale indicate that global plate motion model NUVEL-1 should be modified for comparison with other rates of motion including those estimated from space geodetic measurements. The optimal recalibration, which is a compromise among slightly different calibrations appropriate for slow, medium, and fast rates of seafloor spreading, is to multiply NUVEL-1 angular velocities by a constant, α, of 0.9562. We refer to this simply recalibrated plate motion model as NUVEL-1A, and give correspondingly revised tables of angular velocities and uncertainties. Published work indicates that space geodetic rates are slower on average than those calculated from NUVEL-1 by 6±1%. This average discrepancy is reduced to less than 2% when space geodetic rates are instead compared with NUVEL-1A.
3,359 citations
"A geodetic plate motion and Global ..." refers methods or result in this paper
...[2010] that geodetic estimates differ significantly from the NUVEL-1A geologic model [DeMets et al., 1994]....
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...This finding resonates the conclusion of Argus et al. [2010] that geodetic estimates differ significantly from the NUVEL-1A geologic model [DeMets et al., 1994]....
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...We find that NNR angular velocities differ significantly from those estimated in IGS08, which, through ITRF, has the NNR condition built in using the NNR-NUVEL-1A model [DeMets et al., 1990, 1994; Argus and Gordon, 1991b; Altamimi et al., 2007]....
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01 Jan 1988
TL;DR: In this paper, a new global model (NUVEL-1) was proposed to describe the geologically current motion between 12 assumed-rigid plates by inverting plate motion data.
Abstract: SUMMARY
We determine best-fitting Euler vectors, closure-fitting Euler vectors, and a new global model (NUVEL-1) describing the geologically current motion between 12 assumed-rigid plates by inverting plate motion data we have compiled, critically analysed, and tested for self-consistency. We treat Arabia, India and Australia, and North America and South America as distinct plates, but combine Nubia and Somalia into a single African plate because motion between them could not be reliably resolved. The 1122 data from 22 plate boundaries inverted to obtain NUVEL-1 consist of 277 spreading rates, 121 transform fault azimuths, and 724 earthquake slip vectors. We determined all rates over a uniform time interval of 3.0m.y., corresponding to the centre of the anomaly 2A sequence, by comparing synthetic magnetic anomalies with observed profiles. The model fits the data well. Unlike prior global plate motion models, which systematically misfit some spreading rates in the Indian Ocean by 8–12mm yr−1, the systematic misfits by NUVEL-1 nowhere exceed ∼3 mm yr−1. The model differs significantly from prior global plate motion models. For the 30 pairs of plates sharing a common boundary, 29 of 30 P071, and 25 of 30 RM2 Euler vectors lie outside the 99 per cent confidence limits of NUVEL-1. Differences are large in the Indian Ocean where NUVEL-1 plate motion data and plate geometry differ from those used in prior studies and in the Pacific Ocean where NUVEL-1 rates are systematically 5–20 mm yr−1 slower than those of prior models. The strikes of transform faults mapped with GLORIA and Seabeam along the Mid-Atlantic Ridge greatly improve the accuracy of estimates of the direction of plate motion. These data give Euler vectors differing significantly from those of prior studies, show that motion about the Azores triple junction is consistent with plate circuit closure, and better resolve motion between North America and South America. Motion of the Caribbean plate relative to North or South America is about 7 mm yr−1 slower than in prior global models. Trench slip vectors tend to be systematically misfit wherever convergence is oblique, and best-fitting poles determined only from trench slip vectors differ significantly from their corresponding closure-fitting Euler vectors. The direction of slip in trench earthquakes tends to be between the direction of plate motion and the normal to the trench strike. Part of this bias may be due to the neglect of lateral heterogeneities of seismic velocities caused by cold subducting slabs, but the larger part is likely caused by independent motion of fore-arc crust and lithosphere relative to the overriding plate.
3,328 citations
"A geodetic plate motion and Global ..." refers methods in this paper
...We find that NNR angular velocities differ significantly from those estimated in IGS08, which, through ITRF, has the NNR condition built in using the NNR-NUVEL-1A model [DeMets et al., 1990, 1994; Argus and Gordon, 1991b; Altamimi et al., 2007]....
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TL;DR: This work determines precise GPS satellite positions and clock corrections from a globally distributed network of GPS receivers, and analysis of data from hundreds to thousands of sites every day with 40-Mflop computers yields results comparable in quality to the simultaneous analysis of all data.
Abstract: Networks of dozens to hundreds of permanently operating precision Global Positioning System (GPS) receivers are emerging at spatial scales that range from 10(exp 0) to 10(exp 3) km. To keep the computational burden associated with the analysis of such data economically feasible, one approach is to first determine precise GPS satellite positions and clock corrections from a globally distributed network of GPS receivers. Their, data from the local network are analyzed by estimating receiver- specific parameters with receiver-specific data satellite parameters are held fixed at their values determined in the global solution. This "precise point positioning" allows analysis of data from hundreds to thousands of sites every (lay with 40-Mflop computers, with results comparable in quality to the simultaneous analysis of all data. The reference frames for the global and network solutions can be free of distortion imposed by erroneous fiducial constraints on any sites.
3,013 citations
"A geodetic plate motion and Global ..." refers methods in this paper
...Station coordinates were estimated every 24 h by applying the Precise Point Positioning method to ionospheric-free carrier phase and pseudo-range data [Zumberge et al., 1997]....
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TL;DR: MORVEL as discussed by the authors is a new closure-enforced set of angular velocities for the geologically current motions of 25 tectonic plates that collectively occupy 97 per cent of Earth's surface.
Abstract: SUMMARY
We describe best-fitting angular velocities and MORVEL, a new closure-enforced set of angular velocities for the geologically current motions of 25 tectonic plates that collectively occupy 97 per cent of Earth's surface. Seafloor spreading rates and fault azimuths are used to determine the motions of 19 plates bordered by mid-ocean ridges, including all the major plates. Six smaller plates with little or no connection to the mid-ocean ridges are linked to MORVEL with GPS station velocities and azimuthal data. By design, almost no kinematic information is exchanged between the geologically determined and geodetically constrained subsets of the global circuit—MORVEL thus averages motion over geological intervals for all the major plates. Plate geometry changes relative to NUVEL-1A include the incorporation of Nubia, Lwandle and Somalia plates for the former Africa plate, Capricorn, Australia and Macquarie plates for the former Australia plate, and Sur and South America plates for the former South America plate. MORVEL also includes Amur, Philippine Sea, Sundaland and Yangtze plates, making it more useful than NUVEL-1A for studies of deformation in Asia and the western Pacific. Seafloor spreading rates are estimated over the past 0.78 Myr for intermediate and fast spreading centres and since 3.16 Ma for slow and ultraslow spreading centres. Rates are adjusted downward by 0.6–2.6 mm yr−1 to compensate for the several kilometre width of magnetic reversal zones. Nearly all the NUVEL-1A angular velocities differ significantly from the MORVEL angular velocities. The many new data, revised plate geometries, and correction for outward displacement thus significantly modify our knowledge of geologically current plate motions. MORVEL indicates significantly slower 0.78-Myr-average motion across the Nazca–Antarctic and Nazca–Pacific boundaries than does NUVEL-1A, consistent with a progressive slowdown in the eastward component of Nazca plate motion since 3.16 Ma. It also indicates that motions across the Caribbean–North America and Caribbean–South America plate boundaries are twice as fast as given by NUVEL-1A. Summed, least-squares differences between angular velocities estimated from GPS and those for MORVEL, NUVEL-1 and NUVEL-1A are, respectively, 260 per cent larger for NUVEL-1 and 50 per cent larger for NUVEL-1A than for MORVEL, suggesting that MORVEL more accurately describes historically current plate motions. Significant differences between geological and GPS estimates of Nazca plate motion and Arabia–Eurasia and India–Eurasia motion are reduced but not eliminated when using MORVEL instead of NUVEL-1A, possibly indicating that changes have occurred in those plate motions since 3.16 Ma. The MORVEL and GPS estimates of Pacific–North America plate motion in western North America differ by only 2.6 ± 1.7 mm yr−1, ≈25 per cent smaller than for NUVEL-1A. The remaining difference for this plate pair, assuming there are no unrecognized systematic errors and no measurable change in Pacific–North America motion over the past 1–3 Myr, indicates deformation of one or more plates in the global circuit. Tests for closure of six three-plate circuits indicate that two, Pacific–Cocos–Nazca and Sur–Nubia–Antarctic, fail closure, with respective linear velocities of non-closure of 14 ± 5 and 3 ± 1 mm yr−1 (95 per cent confidence limits) at their triple junctions. We conclude that the rigid plate approximation continues to be tremendously useful, but—absent any unrecognized systematic errors—the plates deform measurably, possibly by thermal contraction and wide plate boundaries with deformation rates near or beneath the level of noise in plate kinematic data.
2,089 citations
"A geodetic plate motion and Global ..." refers background or methods or result in this paper
...Of the 50 plates, 36 angular velocities were estimated from the GPS velocities in our compilation (mostly ones derived by ourselves), 6 were taken from PB2002 [Bird, 2003] and 8 were taken from MORVEL [DeMets et al., 2010]....
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...Our rotation rate for Nazca is significantly slower than the MORVEL estimate, indicating the continued slow-down of the Nazca plate since 0.78 Ma [DeMets et al., 2010]....
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...The Bering, Capricorn, Lwandle are part of the MORVEL plate motion model [DeMets et al., 2010], although MORVEL did not have a rotation rate for Bering, which we estimated from the GPS data....
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...3) Cocos: We used the MORVEL angular velocity for Cocos [DeMets et al., 2010]....
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...We therefore adopted the rotation from MORVEL [DeMets et al., 2010]....
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