Journal articles: 'Crustal dynamics'

1

Mead, Gilbert. "Crustal dynamics research opportunity." Eos, Transactions American Geophysical Union 66, no. 16 (1985): 172. http://dx.doi.org/10.1029/eo066i016p00172-03.

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Coates, Robert J. "The Crustal Dynamics Project." Symposium - International Astronomical Union 129 (1988): 337–38. http://dx.doi.org/10.1017/s0074180900134928.

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The Crustal Dynamics Project has been developing, deploying, and operating very-long-baseline interferometry (VLBI) systems and satellite laser ranging (SLR) systems for highly accurate geodetic measurements of global plate motion, plate stability, regional crustal deformation, and earth rotation/polar motion. Over the past 10 years, the measurement accuracies of these systems have been improved by a factor of 10 to the cm level. Plans are to continue these developments to reach mm level accuracies. The present deployment of the VLBI systems is primarily in the Northern Hemisphere. This network has produced measurements of the relative plate motion between the North American, Eurasian, and Pacific plates; the stability of the same plates; and the regional deformation at the North American/Pacific plate boundary in California and Alaska.

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Campbell, James, and Axel Nothnagel. "European VLBI for crustal dynamics." Journal of Geodynamics 30, no. 3 (February 2000): 321–26. http://dx.doi.org/10.1016/s0264-3707(99)00068-x.

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Zhong, Shijie. "Dynamics of crustal compensation and its influences on crustal isostasy." Journal of Geophysical Research: Solid Earth 102, B7 (July 10, 1997): 15287–99. http://dx.doi.org/10.1029/97jb00956.

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Fadel, Islam, Mark van der Meijde, and Hanneke Paulssen. "Crustal Structure and Dynamics of Botswana." Journal of Geophysical Research: Solid Earth 123, no. 12 (December 2018): 10,659–10,671. http://dx.doi.org/10.1029/2018jb016190.

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Riguzzi, Federica, and Carlo Doglioni. "Gravity and crustal dynamics in Italy." Rendiconti Lincei. Scienze Fisiche e Naturali 31, S1 (February 11, 2020): 49–58. http://dx.doi.org/10.1007/s12210-020-00881-2.

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Sagert, I., O. Korobkin, I. Tews, B. J. Tsao, H. Lim, M. Falato, and J. Loiseau. "Modeling Solids in Nuclear Astrophysics with Smoothed Particle Hydrodynamics." Astrophysical Journal Supplement Series 267, no. 2 (August 1, 2023): 47. http://dx.doi.org/10.3847/1538-4365/acdc94.

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Abstract Smoothed particle hydrodynamics (SPH) is a frequently applied tool in computational astrophysics to solve the fluid dynamics equations governing the systems under study. For some problems, for example when involving asteroids and asteroid impacts, the additional inclusion of material strength is necessary in order to accurately describe the dynamics. In compact stars, that is white dwarfs and neutron stars, solid components are also present. Neutron stars have a solid crust, which is the strongest material known in nature. However, their dynamical evolution, when modeled via SPH or other computational fluid dynamics codes, is usually described as a purely fluid dynamics problem. Here, we present the first 3D simulations of neutron star crustal toroidal oscillations including material strength with the Los Alamos National Laboratory SPH code FleCSPH. In the first half of the paper, we present the numerical implementation of solid material modeling together with standard tests. The second half is on the simulation of crustal oscillations in the fundamental toroidal mode. Here, we dedicate a large fraction of the paper to approaches that can suppress numerical noise in the solid. If not minimized, the latter can dominate the crustal motion in the simulations.

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Björnsson, Axel. "Dynamics of crustal rifting in NE Iceland." Journal of Geophysical Research 90, B12 (1985): 10151. http://dx.doi.org/10.1029/jb090ib12p10151.

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Himwich, W. E. "NASA/Crustal Dynamics Project Geodetic Data Analysis." Symposium - International Astronomical Union 129 (1988): 357–58. http://dx.doi.org/10.1017/s0074180900134989.

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The VLBI group in NASA's Crustal Dynamics Project (CDP) maintains an integrated system for analyzing geodetic VLBI data. This system includes: CALC, calibration programs, SOLVE, GLOBL, and the Data Base System. CALC is the program which contains the models used to calculate the theoretical delay. SOLVE is used to analyze single experiments. GLOBL is used to analyze large groups of experiments. The Data Base System is a self-documenting data storage system used to pass data between programs and archive the data. Kalman filtering is being investigated for operational use in geodetic data analysis.

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Jung, S., and A. Möller. "Crustal dynamics: Links between geochronology and petrology." Chemical Geology 241, no. 1-2 (June 2007): 1–3. http://dx.doi.org/10.1016/j.chemgeo.2007.01.025.

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Coates, Robert J. "The global tracking networks for crustal dynamics." Acta Astronautica 17, no. 1 (January 1988): 53–60. http://dx.doi.org/10.1016/0094-5765(88)90128-2.

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Lerch, F. J., S. M. Klosko, G. B. Patel, and C. A. Wagner. "A gravity model for crustal dynamics (GEM-L2)." Journal of Geophysical Research 90, B11 (1985): 9301. http://dx.doi.org/10.1029/jb090ib11p09301.

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Korenaga, Jun. "Crustal evolution and mantle dynamics through Earth history." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 376, no. 2132 (October 2018): 20170408. http://dx.doi.org/10.1098/rsta.2017.0408.

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Resolving the modes of mantle convection through Earth history, i.e. when plate tectonics started and what kind of mantle dynamics reigned before, is essential to the understanding of the evolution of the whole Earth system, because plate tectonics influences almost all aspects of modern geological processes. This is a challenging problem because plate tectonics continuously rejuvenates Earth's surface on a time scale of about 100 Myr, destroying evidence for its past operation. It thus becomes essential to exploit indirect evidence preserved in the buoyant continental crust, part of which has survived over billions of years. This contribution starts with an in-depth review of existing models for continental growth. Growth models proposed so far can be categorized into three types: crust-based, mantle-based and other less direct inferences, and the first two types are particularly important as their difference reflects the extent of crustal recycling, which can be related to subduction. Then, a theoretical basis for a change in the mode of mantle convection in the Precambrian is reviewed, along with a critical appraisal of some popular notions for early Earth dynamics. By combining available geological and geochemical observations with geodynamical considerations, a tentative hypothesis is presented for the evolution of mantle dynamics and its relation to surface environment; the early onset of plate tectonics and gradual mantle hydration are responsible not only for the formation of continental crust but also for its preservation as well as its emergence above sea level. Our current understanding of various material properties and elementary processes is still too premature to build a testable, quantitative model for this hypothesis, but such modelling efforts could potentially transform the nature of the data-starved early Earth research by quantifying the extent of preservation bias.This article is part of a discussion meeting issue ‘Earth dynamics and the development of plate tectonics’.

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Rey, P. F., C. Teyssier, and D. L. Whitney. "Extension rates, crustal melting, and core complex dynamics." Geology 37, no. 5 (May 2009): 391–94. http://dx.doi.org/10.1130/g25460a.1.

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Coates, Robert, Herbert Frey, Gilbert Mead, and John Bosworth. "Space-Age Geodesy: The NASA Crustal Dynamics Project." IEEE Transactions on Geoscience and Remote Sensing GE-23, no. 4 (July 1985): 360–68. http://dx.doi.org/10.1109/tgrs.1985.289425.

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Vinnik, L. P., S. Roecker, G. L. Kosarev, S. I. Oreshin, and I. Yu Koulakov. "Crustal structure and dynamics of the Tien Shan." Geophysical Research Letters 29, no. 22 (November 2002): 4–1. http://dx.doi.org/10.1029/2002gl015531.

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Gordon, David. "Geodesy by Radio Interferometry: Determination of Vector Motions for Sites in the Western United States." Symposium - International Astronomical Union 129 (1988): 355–56. http://dx.doi.org/10.1017/s0074180900134977.

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Since the late 1970's, NASA's Crustal Dynamics Project has been using Mark III VLBI to study plate tectonic motion, plate boundary deformation and earth dynamics. One major thrust has been the study of crustal motions in the western continental United States. For this effort, several relatively large, fixed antennas (Mojave, Owens Valley, Hatcreek, Ft. Davis and Vandenberg) have been used along with two small, highly mobile VLBI systems which have periodically visited sites of tectonic interest.

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Price, R. E., M. J. Chandler, B. R. Schupler, and P. R. Dachel. "Hydrogen Maser Support of VLBI for the NASA Crustal Dynamics Project." Symposium - International Astronomical Union 129 (1988): 505–6. http://dx.doi.org/10.1017/s0074180900135442.

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For the NASA Crustal Dynamics Project VLBI network, signals from quasars are recorded simultaneously at widely separated antennas. It is well known that hydrogen maser frequency standards provide the stable frequency reference used to precisely measure the difference in arrival time of the radio signals at the different antennas, enabling the determination of precise distances between the antennas. This paper reviews the practical requirements for maser support of VLBI for the Crustal Dynamics Project and describes the means used to meet these requirements for a network of eight fixed and three mobile stations which participate in approximately 200 VLBI experiments per year at locations in North America and the Pacific.

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Singh, Srishti, and Attreyee Ghosh. "The role of crustal models in the dynamics of the India–Eurasia collision zone." Geophysical Journal International 223, no. 1 (June 20, 2020): 111–31. http://dx.doi.org/10.1093/gji/ggaa299.

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SUMMARY We investigate how different crustal models can affect the stress field, velocities and associated deformation in the India–Eurasia collision zone. We calculate deviatoric stresses, which act as deformation indicators, from topographic load distribution and crustal heterogeneities coupled with density driven mantle convection constrained by tomography models. We use three different crustal models, CRUST2.0, CRUST1.0 and LITHO1.0 and observe that these models have different crustal thickness and densities. As a result, gravitational potential energy (GPE) calculated based on these densities and crustal thicknesses differ between these models and so do the associated deviatoric stresses. For GPE only models, LITHO1.0 provides a better constraint on deformation as it yields the least misfit (both orientation and relative magnitude) with the surface observations of strain rates, lithospheric stress, plate motions and earthquake moment tensors. However, when the stresses from GPE are added to those associated with mantle tractions arising from density-driven mantle convection, the coupled models in all cases provide a better fit to surface observations. The N–S tensional stresses predicted by CRUST2.0 in this area get reduced significantly due to addition of large N–S compressional stresses predicted by the tomography models S40RTS and SAW642AN leading to an overall strike-slip regime. On the other hand, the hybrid models, SINGH_S40RTS and SINGH_SAW that are obtained by embedding a regional P-wave model, Singh et al., in global models of S40RTS and SAW642AN, predict much lower compression within this area. These hybrid models provide a better constraint on surface observations when coupled with CRUST1.0 in central Tibet, whereas the combined LITHO1.0 plus mantle traction model provides a better fit in some other areas, but with a degradation of fit in central Tibet.

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Gügercinoğlu, Erbil, and M. Ali Alpar. "The 2016 Vela glitch: a key to neutron star internal structure and dynamics." Monthly Notices of the Royal Astronomical Society 496, no. 2 (June 23, 2020): 2506–15. http://dx.doi.org/10.1093/mnras/staa1672.

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ABSTRACT High-resolution, pulse-to-pulse observation of the 2016 Vela glitch and its relaxation provided an opportunity to probe the neutron star internal structure and dynamics with unprecedented detail. We use the observations of this glitch to infer superfluid characteristics in the framework of the vortex creep model. The glitch rise time constraint of 12.6 s put stringent limits on the angular momentum exchange between the crustal superfluid and the observed crust. Together with the observed excess acceleration in the rotation rate as compared to the post-glitch equilibrium value, this discriminates crustal superfluid-crust lattice and core superfluid-crustal normal matter coupling time-scales. An evident decrease in the crustal rotation rate immediately before the glitch is consistent with the formation of a new vortex trap zone that initiates the large-scale vortex unpinning avalanche. Formation of vortex trap by a crust breaking quake induces short-lived magnetospheric changes. The long-term post-glitch spin-down rate evolution reveals the moments of inertia and recoupling time-scales of the superfluid layers participating in the glitch and leads to an estimation of the time to the next glitch that agrees with the time interval between the 2016 and 2019 glitches. Our results are consistent with theoretical estimates of effective neutron and proton masses in the superfluid. We also constrain the vortex line-flux tube pinning energy per intersection as 2 MeV.

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Burke, William B., Andrew K. Laskowski, Devon A. Orme, Kurt E. Sundell, Michael H. Taylor, Xudong Guo, and Lin Ding. "Record of Crustal Thickening and Synconvergent Extension from the Dajiamang Tso Rift, Southern Tibet." Geosciences 11, no. 5 (May 12, 2021): 209. http://dx.doi.org/10.3390/geosciences11050209.

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North-trending rifts throughout south-central Tibet provide an opportunity to study the dynamics of synconvergent extension in contractional orogenic belts. In this study, we present new data from the Dajiamang Tso rift, including quantitative crustal thickness estimates calculated from trace/rare earth element zircon data, U-Pb geochronology, and zircon-He thermochronology. These data constrain the timing and rates of exhumation in the Dajiamang Tso rift and provide a basis for evaluating dynamic models of synconvergent extension. Our results also provide a semi-continuous record of Mid-Cretaceous to Miocene evolution of the Himalayan-Tibetan orogenic belt along the India-Asia suture zone. We report igneous zircon U-Pb ages of ~103 Ma and 70–42 Ma for samples collected from the Xigaze forearc basin and Gangdese Batholith/Linzizong Formation, respectively. Zircon-He cooling ages of forearc rocks in the hanging wall of the Great Counter thrust are ~28 Ma, while Gangdese arc samples in the footwalls of the Dajiamang Tso rift are 16–8 Ma. These data reveal the approximate timing of the switch from contraction to extension along the India-Asia suture zone (minimum 16 Ma). Crustal-thickness trends from zircon geochemistry reveal possible crustal thinning (to ~40 km) immediately prior to India-Eurasia collision onset (58 Ma). Following initial collision, crustal thickness increases to 50 km by 40 Ma with continued thickening until the early Miocene supported by regional data from the Tibetan Magmatism Database. Current crustal thickness estimates based on geophysical observations show no evidence for crustal thinning following the onset of E–W extension (~16 Ma), suggesting that modern crustal thickness is likely facilitated by an underthrusting Indian lithosphere balanced by upper plate extension.

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Quevedo, Leonardo, Gabriele Morra, and R. Dietmar Müller. "Parallel Fast Multipole Boundary Element Method for crustal dynamics." IOP Conference Series: Materials Science and Engineering 10 (June 1, 2010): 012012. http://dx.doi.org/10.1088/1757-899x/10/1/012012.

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Tetreault, J. L., and S. J. H. Buiter. "Future accreted terranes: a compilation of island arcs, oceanic plateaus, submarine ridges, seamounts, and continental fragments." Solid Earth Discussions 6, no. 2 (July 1, 2014): 1451–521. http://dx.doi.org/10.5194/sed-6-1451-2014.

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Abstract. Allochthonous accreted terranes are exotic geologic units that originated from anomalous crustal regions on a subducting oceanic plate and were transferred to the overriding plate during subduction by accretionary processes. The geographical regions that eventually become accreted allochthonous terranes include island arcs, oceanic plateaus, submarine ridges, seamounts, continental fragments, and microcontinents. These future allochthonous terranes (FATs) contribute to continental crustal growth, subduction dynamics, and crustal recycling in the mantle. We present a review of modern FATs and their accreted counterparts based on available geological, seismic, and gravity studies and discuss their crustal structure, geological origin, and bulk crustal density. Island arcs have an average crustal thickness of 26 km, average bulk crustal density of 2.79 g cm−3, and have 3 distinct crustal units overlying a crust-mantle transition zone. Oceanic plateaus and submarine ridges have an average crustal thickness of 21 km and average bulk crustal density of 2.84 g cm−3. Continental fragments presently on the ocean floor have an average crustal thickness of 25 km and bulk crustal density of 2.81 g cm−3. Accreted allochthonous terranes can be compared to these crustal compilations to better understand which units of crust are accreted or subducted. In general, most accreted terranes are thin crustal units sheared off of FATs and added onto the accretionary prism, with thicknesses on the order of hundreds of meters to a few kilometers. In addition many island arcs, oceanic plateaus, and submarine ridges were sheared off in the subduction interface and underplated onto the overlying continent. And other times we find evidence of collision leaving behind accreted terranes 25 to 40 km thick. We posit that rheologically weak crustal layers or shear zones that were formed when the FATs were produced can be activated as detachments during subduction, allowing parts of the FAT crust to accrete and others to accrete. In many modern FATs on the ocean floor, a sub-crustal layer of high seismic velocities, interpreted as ultramafic material, could serve as a detachment or delaminate during subduction.

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Tetreault, J. L., and S. J. H. Buiter. "Future accreted terranes: a compilation of island arcs, oceanic plateaus, submarine ridges, seamounts, and continental fragments." Solid Earth 5, no. 2 (December 4, 2014): 1243–75. http://dx.doi.org/10.5194/se-5-1243-2014.

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Abstract. Allochthonous accreted terranes are exotic geologic units that originated from anomalous crustal regions on a subducting oceanic plate and were transferred to the overriding plate by accretionary processes during subduction. The geographical regions that eventually become accreted allochthonous terranes include island arcs, oceanic plateaus, submarine ridges, seamounts, continental fragments, and microcontinents. These future allochthonous terranes (FATs) contribute to continental crustal growth, subduction dynamics, and crustal recycling in the mantle. We present a review of modern FATs and their accreted counterparts based on available geological, seismic, and gravity studies and discuss their crustal structure, geological origin, and bulk crustal density. Island arcs have an average crustal thickness of 26 km, average bulk crustal density of 2.79 g cm−3, and three distinct crustal units overlying a crust–mantle transition zone. Oceanic plateaus and submarine ridges have an average crustal thickness of 21 km and average bulk crustal density of 2.84 g cm−3. Continental fragments presently on the ocean floor have an average crustal thickness of 25 km and bulk crustal density of 2.81 g cm−3. Accreted allochthonous terranes can be compared to these crustal compilations to better understand which units of crust are accreted or subducted. In general, most accreted terranes are thin crustal units sheared off of FATs and added onto the accretionary prism, with thicknesses on the order of hundreds of meters to a few kilometers. However, many island arcs, oceanic plateaus, and submarine ridges were sheared off in the subduction interface and underplated onto the overlying continent. Other times we find evidence of terrane–continent collision leaving behind accreted terranes 25–40 km thick. We posit that rheologically weak crustal layers or shear zones that were formed when the FATs were produced can be activated as detachments during subduction, allowing parts of the FAT crust to accrete and others to subduct. In many modern FATs on the ocean floor, a sub-crustal layer of high seismic velocities, interpreted as ultramafic material, could serve as a detachment or delaminate during subduction.

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Olga F. Lukhneva and Anna Vladimirovna Novopashina. "The propagation velocity of seismic activity migrating along the directions of the geodynamic forces prevailing in the northeastern Baikal rift system, Russia." Annals of Geophysics 64, no. 4 (November 16, 2021): SE436. http://dx.doi.org/10.4401/ag-8654.

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The recent tectonic stress field in the northeastern Baikal rift system (BRS) corresponds to the crustal deformation field. The stress-strain state of the Earth’s crust determines the fault network geometry and spatiotemporal structure of the epicentral field characterized by many earthquake swarms and earthquake migrations in the study area. In order to study the seismic process dynamics in different directions of the crustal deformation, the spatiotemporal analysis of earthquake time series has been made over the 1964–2015 instrumental period. To determine the relationship between crustal stress and spatiotemporal features of the epicentral field the seismic data were projected along horizontal stress tensor axes σ3 and σ2, consistent with major directions of the crustal deformation, a strike of major rifting structures, and a general azimuth of active fault groups. The NE-SW direction along the intermediate horizontal stress axes and main faulted arears exhibits slow earthquake migrations up to 60 km long, propagating with a modal velocity of about 30 kilometers per year. The NW-SE direction along the principal horizontal stress axes, orthogonal to the main faulted areas, is characterized by shorter migration sequences of less duration, propagating with a higher velocity than sequences registered in the NE-SW. The difference between the migration dynamics in mutually orthogonal directions can be attributed to the fault network configuration and the differences in the deformation process.

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Ventura, Guido, Francesca R. Cinti, Francesca Di Luccio, and N. Alessandro Pino. "Mantle wedge dynamics versus crustal seismicity in the Apennines (Italy)." Geochemistry, Geophysics, Geosystems 8, no. 2 (February 2007): n/a. http://dx.doi.org/10.1029/2006gc001421.

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Valenti, Vera, Raimondo Catalano, Pingsheng Wei, and Shujiang Wang. "Layered lower crust and mantle reflectivity as imaged by a re-processed crustal seismic profile from Sicily in the central Mediterranean." Bulletin de la Société Géologique de France 186, no. 4-5 (July 1, 2015): 257–72. http://dx.doi.org/10.2113/gssgfbull.186.4-5.257.

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Abstract Though Sicily is a key area for understanding the central Mediterranean tectonics, a number of questions on its dynamics remains open due to the lack of detailed data on the lithospheric structure. Deep reflectivity images of the African lithosphere, beneath Sicily, have been derived from the re-processing of the crustal seismic reflection stack (SI.RI.PRO. Project). Of specific interest was the imaging, beneath central-southern Sicily, of a thinned crust with a reflective, “layered” pattern for the lower crust that differs from the one, thicker and sub-transparent, of the northern-central sector. Brittle deformation in the upper crystalline crust along a low-angle normal fault and sub-horizontal sub-Moho events are the main features, spatially associated with the “layered”, attenuated lower crust. Geological implications, which are related to the above-mentioned crustal characters, that allow us to suppose two combined hypotheses (the first suggesting that the crustal features derive from the effects of Permian and Mesozoic rifting cycles, the second connecting the crustal thinning to the latest Pliocene-Pleistocene volcanic activity and tectonics), are here discussed. The imaging of the Moho patterns and the crustal/sub-crustal reflectivity characteristics, here illustrated for the first time, could provide constraints for the geodynamic processes governing this area where an interaction between African and Tyrrhenian European plates occurs.

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Zhu, Tao, Yan Zhan, Martyn Unsworth, Guoze Zhao, and Xiangyu Sun. "High-resolution lithosphere viscosity structure and the dynamics of the 2008 Wenchuan earthquake area: new constraints from magnetotelluric imaging." Geophysical Journal International 222, no. 2 (May 2, 2020): 1352–62. http://dx.doi.org/10.1093/gji/ggaa214.

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SUMMARY Estimation of lithospheric viscosity remains challenging, especially for variations with spatial scales less than 100 km. Some recent studies have developed a method to determine viscosity structure from electrical conductivity models determined from magnetotelluric (MT) data. This method was initially applied to the extensional transition zone from the Great Basin to Colorado Plateau. Here, we use this approach to infer the effective lithospheric viscosity in a convergent setting by using an MT profile that crosses the eastern margin of the Tibetan Plateau. The profile extends from the Songpan-Ganzi block, crosses the 2008 Wenchuan earthquake epicentre region and ends in the Sichuan basin. The preferred viscosity structure is characterized by the middle-lower crustal viscosities in the range 2.42 × 1018 to 2.69 × 1021 Pa s below the Songpan-Ganzi block. In the Longmenshan fault zone and 2008 Wenchuan Ms8.0 earthquake area, the crustal viscosity is higher and in the range 4.32 × 1018 to 5.10 × 1021 Pa s with significant small-scale (<100 km) lateral variations. The MT-derived viscosities are consistent with previous regional-scale estimates but reveal the viscosity structure in more detail. The preferred geodynamic model can explain both the crustal deformation velocity and the small-scale lateral variations of surface topography. It implies that the crustal deformation is driven by mantle flow that results in a weak coupling of the upper and middle-lower crust beneath the eastern Tibetan Plateau. The inferred viscosity structure may help further understand the earthquake mechanisms in the Longmenshan fault zone.

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Delorey, Andrew A., Kevin Chao, Kazushige Obara, and Paul A. Johnson. "Cascading elastic perturbation in Japan due to the 2012 Mw 8.6 Indian Ocean earthquake." Science Advances 1, no. 9 (October 2015): e1500468. http://dx.doi.org/10.1126/sciadv.1500468.

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Since the discovery of extensive earthquake triggering occurring in response to the 1992 Mw (moment magnitude) 7.3 Landers earthquake, it is now well established that seismic waves from earthquakes can trigger other earthquakes, tremor, slow slip, and pore pressure changes. Our contention is that earthquake triggering is one manifestation of a more widespread elastic disturbance that reveals information about Earth’s stress state. Earth’s stress state is central to our understanding of both natural and anthropogenic-induced crustal processes. We show that seismic waves from distant earthquakes may perturb stresses and frictional properties on faults and elastic moduli of the crust in cascading fashion. Transient dynamic stresses place crustal material into a metastable state during which the material recovers through a process termed slow dynamics. This observation of widespread, dynamically induced elastic perturbation, including systematic migration of offshore seismicity, strain transients, and velocity transients, presents a new characterization of Earth’s elastic system that will advance our understanding of plate tectonics, seismicity, and seismic hazards.

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Charlot, Patrick, Jean-François Lestrade, and Claude Boucher. "3C 273 and DA 193 Mapped with Crustal Dynamics VLBI Data." Symposium - International Astronomical Union 129 (1988): 33–34. http://dx.doi.org/10.1017/s007418090013387x.

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Hybrid maps of 3C 273 and DA 193 at 2.3 and 8.4 GHz have been produced with VLBI data acquired during a Crustal Dynamics campaign. By comparing to maps at previous epochs, superluminal components of 3C 273 are clearly detected. DA 193 is relatively compact. Structure corrections for the VLBI delay used in astrometry have been estimated from these maps. Some corrections are significant when compared with the precision of models used in astrometry and geodesy.

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Fay, N. P., R. A. Bennett, J. C. Spinler, and E. D. Humphreys. "Small-scale upper mantle convection and crustal dynamics in southern California." Geochemistry, Geophysics, Geosystems 9, no. 8 (August 2008): n/a. http://dx.doi.org/10.1029/2008gc001988.

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Ma, C. "The VLBI celestial reference frame of the NASA Crustal Dynamics Project." Symposium - International Astronomical Union 128 (1988): 73–81. http://dx.doi.org/10.1017/s0074180900119308.

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A celestial reference frame can be defined by precise positions of extragalactic radio sources using Mark III VLBI data available to the NASA Crustal Dynamics Project for geodynamic research. Seven years of such data have been analyzed to generate a catalogue of 101 sources with formal statistical errors between 0.01 and 0.77 ms in right ascension and between 0.2 and 9.3 mas in declination. In order to achieve such precision it is necessary to adjust the standard IAU nutation model. The rotations and scatter of the positions from year to year are generally less than 1 mas. A comparison of this catalogue with a completely independent catalogue derived from Mark II data shows a weighted average position difference, after a rotation, of 1.9 mas.

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Li, Yujiang, Mian Liu, Yuhang Li, and Lianwang Chen. "Active crustal deformation in southeastern Tibetan Plateau: The kinematics and dynamics." Earth and Planetary Science Letters 523 (October 2019): 115708. http://dx.doi.org/10.1016/j.epsl.2019.07.010.

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Austrheim, Håkon. "Eclogite formation and dynamics of crustal roots under continental collision zones." Terra Nova 3, no. 5 (September 1991): 492–99. http://dx.doi.org/10.1111/j.1365-3121.1991.tb00184.x.

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Huppert, Herbert E., R. Stephen, and J. Sparks. "The fluid dynamics of crustal melting by injection of basaltic sills." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 79, no. 2-3 (1988): 237–43. http://dx.doi.org/10.1017/s0263593300014243.

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ABSTRACTWhen basaltic magma is emplaced into continental crust, melting and generation of granitic magma can occur. We present experimental and theoretical investigations of the fluid dynamical and heat transfer processes at the roof and floor of a basaltic sill in which the wall rocks melt. At the floor, relatively low density crustal melt rises and mixes into the overlying magma, which would form hybrid andesitic magma. Below the roof the low-density melt forms a stable layer with negligible mixing between it and the underlying hotter, denser magma. Our calculations applied to basaltic sills in hot crust predict that sills from 10-1500 m thick require only 2-200 years to solidify, during which time large volumes of overlying layers of convecting silicic magma are formed. These time scales are very short compared with the lifetimes of large silicic magma systems of around 106 years, and also with the time scale of 107 years for thermal relaxation of the continental crust. An important feature of the process is that crystallisation and melting occur simultaneously, though in different spots of the source region. The granitic magmas formed are thus a mixture of igneous phenocrysts and lesser amounts of restite crystals. Several features of either plutonic or volcanic silicic systems can be explained without requiring large, high-level, long-lived magma chambers.

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Khan, Aftab Alam, and R. K. S. Chouhan. "The crustal dynamics and the tectonic trends in the Bengal Basin." Journal of Geodynamics 22, no. 3-4 (November 1996): 267–86. http://dx.doi.org/10.1016/0264-3707(96)00022-1.

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37

YE, Zheng-Ren, and Jian WANG. "Dynamics of the Present-Day Crustal Movement in the China Mainland." Chinese Journal of Geophysics 47, no. 3 (May 2004): 518–24. http://dx.doi.org/10.1002/cjg2.515.

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38

Sahin, M., P. N. Rands, and P. A. Cross. "Crustal dynamics in Turkey from WEGENER/MEDLAS satellite laser ranging data." Geological Journal 28, no. 3-4 (December 1993): 347–55. http://dx.doi.org/10.1002/gj.3350280313.

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39

Kawada, Y., H. Nagahama, Y. Omori, Y. Yasuoka, T. Ishikawa, S. Tokonami, and M. Shinogi. "Time-scale invariant changes in atmospheric radon concentration and crustal strain prior to a large earthquake." Nonlinear Processes in Geophysics 14, no. 2 (March 19, 2007): 123–30. http://dx.doi.org/10.5194/npg-14-123-2007.

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Abstract. Prior to large earthquakes (e.g. 1995 Kobe earthquake, Japan), an increase in the atmospheric radon concentration is observed, and this increase in the rate follows a power-law of the time-to-earthquake (time-to-failure). This phenomenon corresponds to the increase in the radon migration in crust and the exhalation into atmosphere. An irreversible thermodynamic model including time-scale invariance clarifies that the increases in the pressure of the advecting radon and permeability (hydraulic conductivity) in the crustal rocks are caused by the temporal changes in the power-law of the crustal strain (or cumulative Benioff strain), which is associated with damage evolution such as microcracking or changing porosity. As the result, the radon flux and the atmospheric radon concentration can show a temporal power-law increase. The concentration of atmospheric radon can be used as a proxy for the seismic precursory processes associated with crustal dynamics.

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Nebel, O., F. A. Capitanio, J. F. Moyen, R. F. Weinberg, F. Clos, Y. J. Nebel-Jacobsen, and P. A. Cawood. "When crust comes of age: on the chemical evolution of Archaean, felsic continental crust by crustal drip tectonics." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 376, no. 2132 (October 2018): 20180103. http://dx.doi.org/10.1098/rsta.2018.0103.

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The secular evolution of the Earth's crust is marked by a profound change in average crustal chemistry between 3.2 and 2.5 Ga. A key marker for this change is the transition from Archaean sodic granitoid intrusions of the tonalite–trondhjemite–granodiorite (TTG) series to potassic (K) granitic suites, akin (but not identical) to I-type granites that today are associated with subduction zones. It remains poorly constrained as to how and why this change was initiated and if it holds clues about the geodynamic transition from a pre-plate tectonic mode, often referred to as stagnant lid, to mobile plate tectonics. Here, we combine a series of proposed mechanisms for Archaean crustal geodynamics in a single model to explain the observed change in granitoid chemistry. Numeric modelling indicates that upper mantle convection drives crustal flow and subsidence, leading to profound diversity in lithospheric thickness with thin versus thick proto-plates. When convecting asthenospheric mantle interacts with lower lithosphere, scattered crustal drips are created. Under increasing P-T conditions, partial melting of hydrated meta-basalt within these drips produces felsic melts that intrude the overlying crust to form TTG. Dome structures, in which these melts can be preserved, are a positive diapiric expression of these negative drips. Transitional TTG with elevated K mark a second evolutionary stage, and are blends of subsided and remelted older TTG forming K-rich melts and new TTG melts. Ascending TTG-derived melts from asymmetric drips interact with the asthenospheric mantle to form hot, high-Mg sanukitoid. These melts are small in volume, predominantly underplated, and their heat triggered melting of lower crustal successions to form higher-K granites. Importantly, this evolution operates as a disseminated process in space and time over hundreds of millions of years (greater than 200 Ma) in all cratons. This focused ageing of the crust implies that compiled geochemical data can only broadly reflect geodynamic changes on a global or even craton-wide scale. The observed change in crustal chemistry does mark the lead up to but not the initiation of modern-style subduction. This article is part of a discussion meeting issue ‘Earth dynamics and the development of plate tectonics’.

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Castellanos, Jorge C., Jonathan Perry-Houts, Robert W. Clayton, YoungHee Kim, A. Christian Stanciu, Bart Niday, and Eugene Humphreys. "Seismic anisotropy reveals crustal flow driven by mantle vertical loading in the Pacific NW." Science Advances 6, no. 28 (July 2020): eabb0476. http://dx.doi.org/10.1126/sciadv.abb0476.

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Buoyancy anomalies within Earth’s mantle create large convective currents that are thought to control the evolution of the lithosphere. While tectonic plate motions provide evidence for this relation, the mechanism by which mantle processes influence near-surface tectonics remains elusive. Here, we present an azimuthal anisotropy model for the Pacific Northwest crust that strongly correlates with high-velocity structures in the underlying mantle but shows no association with the regional mantle flow field. We suggest that the crustal anisotropy is decoupled from horizontal basal tractions and, instead, created by upper mantle vertical loading, which generates pressure gradients that drive channelized flow in the mid-lower crust. We then demonstrate the interplay between mantle heterogeneities and lithosphere dynamics by predicting the viscous crustal flow that is driven by local buoyancy sources within the upper mantle. Our findings reveal how mantle vertical load distribution can actively control crustal deformation on a scale of several hundred kilometers.

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Zhu, Guang, Yuanchao Lu, Nan Su, Xiaodong Wu, Hao Yin, Shuai Zhang, Chenglong Xie, and Manlan Niu. "Crustal deformation and dynamics of Early Cretaceous in the North China Craton." Science China Earth Sciences 64, no. 9 (April 14, 2021): 1428–50. http://dx.doi.org/10.1007/s11430-020-9749-0.

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Gutscher, Marc-André. "Crustal structure and dynamics in the Rhine Graben and the Alpine foreland." Geophysical Journal International 122, no. 2 (September 1995): 617–36. http://dx.doi.org/10.1111/j.1365-246x.1995.tb07016.x.

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Zhou, Shuo-Yu, Yun Wu, Ruo-Bo Wang, and Guo-Hua Yang. "Research of pattern dynamics parameters of crustal deformation field in seismogenic process." Acta Seismologica Sinica 7, no. 3 (August 1994): 427–32. http://dx.doi.org/10.1007/bf02650680.

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Rampone, Elisabetta, and Alessio Sanfilippo. "The Heterogeneous Tethyan Oceanic Lithosphere of the Alpine Ophiolites." Elements 17, no. 1 (February 1, 2021): 23–28. http://dx.doi.org/10.2138/gselements.17.1.23.

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The Alpine–Apennine ophiolites are lithospheric remnants of the Jurassic Alpine Tethys Ocean. They predominantly consist of exhumed mantle peridotites with lesser gabbroic and basaltic crust and are locally associated with continental crustal material, indicating formation in an environment transitional from an ultra-slow-spreading seafloor to a hyperextended passive margin. These ophiolites represent a unique window into mantle dynamics and crustal accretion in an ultra-slow-spreading extensional environment. Old, pre-Alpine, lithosphere is locally preserved within the mantle sequences: these have been largely modified by reaction with migrating asthenospheric melts. These reactions were active in both the mantle and the crust and have played a key role in creating the heterogeneous oceanic lithosphere in this branch of the Mesozoic Western Tethys.

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Ryan, J. W., and T. A. Clark. "NASA/Crustal Dynamics Project Results: Tectonic Plate Motion Measurements with Mark-III VLBI." Symposium - International Astronomical Union 129 (1988): 339–40. http://dx.doi.org/10.1017/s007418090013493x.

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The NASA Crustal Dynamics Project (CDP) has been using VLBI on intercontinental baselines to measure tectonic plate motions since 1979. We report on measurements between sites on the North American plate (Haystack/Westford, MA; Owens Valley and Mojave, CA; Ft. Davis, TX and Gilmore Creek, AK), the Eurasian plate (Onsala, Sweden; Wettzell, West Germany, and Shanghai, China), the Pacific plate (Kauai, HI; Kwajalein in the Marshall Islands, and Vandenberg AFB, CA), the African plate (Hartebesthoek, RSA), and Japan (Kashima).

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Ouyang, Yuan, Wunian Yang, Hanxiao Huang, Hong Liu, Jianlong Zhang, and Jianhua Zhang. "Metallogenic Dynamics Background of Ga’erqiong Cu-Au Deposit in Tibet, China." Earth Sciences Research Journal 21, no. 2 (April 1, 2017): 59–65. http://dx.doi.org/10.15446/esrj.v21n2.65192.

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The Ga’erqiong Cu-Au deposit, which sits on the north side of the Coqên-Xainzamagmatite belt, is a large-scale skarn-type deposit, whose ore body has formed in the skarn zone in the contact part of quartz diorite and marble of Duoai formation or the cracks of quartz diorite. Its mineralization is closely related to quartz diorite. And granite porphyry-related molybdenum ore still exists in its deep part. Currently, there are disputes about the metallogenic dynamics background of this deposit. From previous studies, this paper carried out zircon LA-LCPMS U-Pb dating and petrogeochemistry study for quartz diorite of Ga’erqiong Cu-Au deposit. The testing result indicates: quartz diorite and granite porphyry were formed respectively in 88±2Ma and 83±1Ma, belonging to the magmatic activity of the early stage of Upper Cretaceous; quartz diorite and granite porphyry have geochemical characteristics similar to those of island arc rock of subduction zone and geochemical indexes similar to “adakite.” Combining with the regional tectonic evolution, we think that quartz diorite and granite porphyry were all formed in the extension environment after the collision of Lhasa block and Qiangtang block. Quartz diorite is the result of the migmatization of basic melt and acid melt evoked by asthenosphere material raise caused by lower crustal delamination; the formation of granite porphyry may be crust-mantle material’s partial melting results due to delaminated lower crustal. Therefore, Ga’erqiongskarn-type Cu-Au deposit belongs to the metallogenic response to the collisional orogeny in the closing process of Meso-Tethys.

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Qu, Wei, Hailu Chen, Shichuan Liang, Qin Zhang, Lihua Zhao, Yuan Gao, and Wu Zhu. "Adaptive Least-Squares Collocation Algorithm Considering Distance Scale Factor for GPS Crustal Velocity Field Fitting and Estimation." Remote Sensing 11, no. 22 (November 18, 2019): 2692. http://dx.doi.org/10.3390/rs11222692.

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High-precision, high-reliability, and high-density GPS crustal velocity are extremely important requirements for geodynamic analysis. The least-squares collocation algorithm (LSC) has unique advantages over crustal movement models to overcome observation errors in GPS data and the sparseness and poor geometric distribution in GPS observations. However, traditional LSC algorithms often encounter negative covariance statistics, and thus, calculating statistical Gaussian covariance function based on the selected distance interval leads to inaccurate estimation of the correlation between the random signals. An unreliable Gaussian statistical covariance function also leads to inconsistency in observation noise and signal variance. In this study, we present an improved LSC algorithm that takes into account the combination of distance scale factor and adaptive adjustment to overcome these problems. The rationality and practicability of the new algorithm was verified by using GPS observations. Results show that the new algorithm introduces the distance scale factor, which effectively weakens the influence of systematic errors by improving the function model. The new algorithm can better reflect the characteristics of GPS crustal movement, which can provide valuable basic data for use in the analysis of regional tectonic dynamics using GPS observations.

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Mikheeva, A. V., and I. I. Kalinnikov. "On the influence of deep seismicity on the preparation of large earthquakes in the South-Asian region." Interexpo GEO-Siberia 4 (May 18, 2022): 124–31. http://dx.doi.org/10.33764/2618-981x-2022-4-124-131.

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The change dynamics in the creepex parameter over time and its comparison with changes in other earthquake parameters (magnitude and depth) is used to test the thesis about the influence on strong crustal events from deep processes associated with the transformation and movement of matter in the upper mantle using the example of the seismicity of the South-Asian region.

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Dilek, Yildirim, and Şafak Altunkaynak. "Cenozoic Crustal Evolution and Mantle Dynamics of Post-Collisional Magmatism in Western Anatolia." International Geology Review 49, no. 5 (May 2007): 431–53. http://dx.doi.org/10.2747/0020-6814.49.5.431.

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Journal articles on the topic 'Crustal dynamics'

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