Download or read book Using Seismic Methods to Constrain Mantle Convection Processes written by Mei Xue and published by . This book was released on 2008 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mantle Convection and Surface Expressions written by Hauke Marquardt and published by John Wiley & Sons. This book was released on 2021-07-07 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: A multidisciplinary perspective on the dynamic processes occurring in Earth's mantle The convective motion of material in Earth's mantle, powered by heat from the deep interior of our planet, drives plate tectonics at the surface, generating earthquakes and volcanic activity. It shapes our familiar surface landscapes, and also stabilizes the oceans and atmosphere on geologic timescales. Mantle Convection and Surface Expressions brings together perspectives from observational geophysics, numerical modelling, geochemistry, and mineral physics to build a holistic picture of the deep Earth. It explores the dynamic processes occurring in the mantle as well as the associated heat and material cycles. Volume highlights include: Perspectives from different scientific disciplines with an emphasis on exploring synergies Current state of the mantle, its physical properties, compositional structure, and dynamic evolution Transport of heat and material through the mantle as constrained by geophysical observations, geochemical data and geodynamic model predictions Surface expressions of mantle dynamics and its control on planetary evolution and habitability The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals.
Download or read book Linking Surface Evolution with Mantle Dynamic Processes Using Adjoint Models with Data Assimilation written by Lijun Liu and published by . This book was released on 2010 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantifying the relationship between subsolidus mantle convection and surface evolution is a fundamental goal of geophysics. Toward this goal progress has been slow due to incomplete knowledge of the earth's internal structure and properties. While seismic tomography reveals details on internal 3D structure of the present mantle, evolution of the subsolidus mantle during the geological past remains elusive. This thesis attempts to solve the time inversion of mantle convection using the adjoint method based on present-day seismic images and geological and geophysical observations dictating the past evolution of solid earth. The adjoint method, widely used in meteorological and oceanographic predictions, can be applied to mantle convection for the recovery of unknown initial conditions through the assimilation of present-day mantle seismic structure. We propose that an optimal first guess to the initial condition can be obtained through a simple backward integration (SBI) of the governing equations thus lessening the computational expense. By incorporating time-dependent surface dynamic topography in addition to present-day mantle structure, the adjoint method is improved so as to constrain uncertain mantle dynamic properties and initial condition simultaneously. The theory is derived from the governing equations of mantle convection and validated by synthetic experiments for a single- and two-layer viscosity mantle within regionally bounded spherical shells. For both cases, we show that the theory can constrain mantle properties with errors arising through the adjoint recovery of the initial condition. For the two-layer model, there is a trade-off between the temperature scaling and lower mantle viscosity. By assimilating seismic structure and plate motions in the inverse mantle convection model, we reconstruct Farallon plate subduction back to 100 Ma. We put constraints on basic mantle properties, including both the depth dependence of mantle viscosity and slab buoyancy, by predicting proxies of dynamic topography evident in the stratigraphy of the North American Cretaceous western interior seaway. Models that fit stratigraphy well require the Farallon slab to have been flat lying in the Late Cretaceous, consistent with geological reconstructions. The models predict an extensive zone of shallow-dipping subduction extending beyond the flat-lying slab farther east and north, while the limited region of subducting flat slab resembles an oceanic plateau. In order to test the hypothesis of oceanic plateau subduction and its relationship to the Laramide orogeny, we compare the inverse convection model with plate reconstructions. Two prominent seismic anomalies on the Farallon plate recovered from inverse models coincide with paleogeographically-restored positions of conjugates to the Shatsky and Hess plateaus when they subducted beneath North America. The distributed shortening of the Laramide orogeny closely tracked the passage of the Shatsky conjugate beneath North America, while the effects of Hess conjugate subduction were restricted to the northern Mexico foreland belt. We find that Laramide uplifts were consequences of the removal, rather than the emplacement, of the Shatsky conjugate, and we predict that these subducted plateaus should be detectable by the USArray seismic experiment. The inverse convection models predict a continuous vertical motion history of western U.S., which is further validated by constraints on the vertical motion of the Colorado Plateau since the Cretaceous. With the arrival of the flat-lying Farallon slab, dynamic subsidence swept from west to east over the western U.S., peaking at 86 Ma within the Colorado Plateau. This eastward migrating dynamic subsidence is consistent with a recently compiled backstripping study that shows a long-wavelength residual subsidence shifting to the east, coincident with the passage of the flat slab beneath North America in our inverse model. Two stages of uplift followed the removal of the Farallon slab below the Colorado Plateau: one in the latest Cretaceous, and the other in the Eocene, with a cumulative uplift of ~1.2 km; the former represents the Laramide uplift which also marks the initial uplift of the entire western U.S. Both the descent of the slab and buoyant upwellings raised the Colorado Plateau to its current elevation during the Oligocene. A locally thick lithosphere enhances coupling to the upper mantle so that the Colorado Plateau has a higher topography with sharp edges. Our models also predict that the plateau tilted downward to the northeast before the Oligocene, caused by northeast-trending subduction of the Farallon slab, and that this northeast tilting diminished and reversed to the southwest during the Miocene in response to buoyant upwellings. Overall, this thesis shows that the adjoint models with data assimilation are useful in linking surface evolution to deep mantle processes both over North America and areas beyond. While more research is clearly needed to construct a more earth-like model, this thesis presents an important advance in data-oriented geodynamic models.
Download or read book Constraints on Mantle Convection from Seismic Tomography and Flow Modeling written by Hrafnkell Kárason and published by . This book was released on 2002 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis I combine high resolution seismic tomography and realistic flow modeling to constrain mantle convection. The bulk of the data used in the tomographic imaging are millions of P, pP and pwP travel time residuals, read from high frequency seismic records. The distribution of earthquakes and stations results in uneven data coverage and to improve the model I use core phases (PKP, Pdiff) for the deep mantle and surface reflected phases (PP) for the shallow mantle. Since narrow rays are not adequate for low frequency measurements, I construct broad 3-D sensitivity kernels to relate some of the added data to earth's structure. Furthermore, the parameterization of the tomographic model is adapted to data density and the model shows, among other details, the varying style of subduction in the shallow mantle and complex flow patterns around the transition zone between the upper and lower mantle. I develop a novel and efficient method of modeling buoyancy driven mantle flow in spherical geometry. Here, the linear Stokes equation is solved using a Green's function approach and 3-D surfaces, representing the boundaries of dense material, such as subducting slabs, are tracked through time.
Download or read book Seismology and Structure of the Earth written by Barbara Romanowicz and published by Elsevier. This book was released on 2010-04-20 with total page 873 pages. Available in PDF, EPUB and Kindle. Book excerpt: Treatise on Geophysics: Seismology and Structure of the Earth, Volume 1, provides a comprehensive review of the state of knowledge on the Earths structure and earthquakes. It addresses various aspects of structural seismology and its applications to other fields of Earth sciences. The book is organized into four parts. The first part principally covers theoretical developments and seismic data analysis techniques from the end of the nineteenth century until the present, with the main emphasis on the development of instrumentation and its deployment. The second part reviews the status of knowledge on the structure of the Earths shallow layers, starting with a global review of the Earth's crustal structure. The third part focuses on the Earth's deep structure, divided into its main units: the upper mantle, the transition zone and upper-mantle discontinuities, the D region at the base of the mantle, and the Earth's core. The fourth part comprises two chapters which discuss constraints on Earth structure from fields other than seismology: mineral physics and geodynamics. Self-contained volume starts with an overview of the subject then explores each topic with in depth detail Extensive reference lists and cross references with other volumes to facilitate further research Full-color figures and tables support the text and aid in understanding Content suited for both the expert and non-expert
Download or read book A New Method for Studying the Mantle Convection Using Phase Relations and Seismic Reflections written by Tomoo Katsura and published by . This book was released on 1990 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plate Deformation from Cradle to Grave written by Andy Nowacki and published by Springer Science & Business Media. This book was released on 2012-12-14 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Earth's rocky mantle convects to lose heat, which comes from the liquid iron core below. The mantle's interfaces - the core-mantle boundary, and the lithosphere - may hold the key to understanding mantle motion because of the seismic anisotropy present in these parts of the Earth. In this thesis, Andy Nowacki presents a precise but comprehensive review of the current state of the art in studying flow with anisotropy, mineral physics and geodynamics. New measurements of shear wave anisotropy in the lowermost mantle and at mid-ocean ridges are used to constrain mechanisms of creep and melt extraction in the mantle. A model of global flow is used to predict anisotropy in the deep Earth, and novel methods to forward model shear wave splitting are described. Future studies of mantle flow must incorporate the understanding gained in this thesis. The thesis contains a substantive introduction to the structure of the Earth, seismic anisotropy in general and in the core-mantle boundary region, and mid-ocean ridge processes. It also describes novel methods for forward modelling and interpreting shear wave splitting data. Three chapters present timely research into dynamics at divergent plate boundaries and at the core-mantle boundary.
Download or read book The Core Mantle Boundary Region written by Michael Gurnis and published by American Geophysical Union. This book was released on 1998-02-04 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: The two giant heat engines responsible for plate tectonics and the geodynamo dynamically interact at the core-mantle boundary of the Earth's interior. A multidisciplinary approach is required to determine the composition, structure, and dynamics of the interface. This volume describes original and fundamental research in seismology, geodynamics, mineral physics, and geomagnetism.
Download or read book Geodynamics of Lithosphere Earth s Mantle written by Jaroslava Plomerova and published by Birkhäuser. This book was released on 2012-12-06 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plate tectonics has significantly broadened our view of the dynamics of continental evolution, involving both the processes currently active at the surface and those extending deep into the interior of the Earth. Seismic anisotropy provides some of the most diagnostic evidence for mapping past and present deformation of the entire crustmantle system. This volume contains papers presented originally at an international workshop at the Chateau of Trest in the Czech Republic in 1996. This workshop brought together geophysicists and geologists who work in the field of observational and theoretical seismology, mineral and rock physics, gravity studies and geodynamic modelling. Topics include large-scale anisotropy of the Earth's mantle, mantle heterogeneity vs. anisotropy 3-D velocity and density structures and inferences on mantle dynamics, mineral and rock physics studies, and mathematical aspects of complex wave propagation.
Download or read book Constraining Mantle Heterogeneity and Mantle Flow Using Seismic and Geodynamic Data written by Chang Lu (Ph. D.) and published by . This book was released on 2018 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, I have developed new 3-D models of mantle heterogeneity using seismic and geodynamic data to better understand the thermo-chemical composition of the mantle and its dynamics. First, the effect of subducting slabs in global shear wave tomography has been evaluated. By performing a synthetic test, I showed that the existence of subducting slabs could lead to serious earthquake mislocation problems. The mislocation biased travel time residuals, affected the recovery of subducting slabs in tomography, and also introduced significant artifacts into lower mantle structure. The bias was reduced if the tomography inversion used a starting model with 3-D slabs and velocity and source location were simultaneously modeled. I next developed a new tomography model by jointly inverting P and S wave seismic data. In this inversion, a 3-D thermal model of subducting slabs was used as the starting model. The new P and S models featured higher amplitude subducting slabs compared to previous global tomography results. The S to P heterogeneity ratio based on the new tomography model indicates the existence of chemical heterogeneities in the lower mantle although less than some previous studies have found. To better constrain the thermo-chemical structure, and dynamics of Earth’s mantle, I performed joint inversions using seismic and geodynamic data simultaneously. The geodynamic observations include free-air gravity, tectonic plate motions, dynamic surface topography, and excess ellipticity of the core-mantle boundary. These geodynamic observations can be related to density perturbations in the mantle assuming a known mantle viscosity model. Five different viscosity models were tested in the joint inversion. In all of these inversions, a non-thermal origin of density anomalies is required to explain the geodynamic data, though the amount of non-thermal heterogeneities varies between models. Using derived density models and their corresponding viscosity profiles, current mantle convective flow fields were also predicted. Flow fields derived using different viscosity models are similar in general. However, using density models derived from joint inversions compared to scaled seismic velocity models lead to significant differences in predicted mantle flow.
Download or read book Encyclopedia of Solid Earth Geophysics written by D.E. James and published by Springer Science & Business Media. This book was released on 1989-11-30 with total page 1299 pages. Available in PDF, EPUB and Kindle. Book excerpt: Consisting of more than 150 articles written by leading experts, this authoritative reference encompasses the entire field of solid-earth geophysics. It describes in detail the state of current knowledge, including advanced instrumentation and techniques, and focuses on important areas of exploration geophysics. It also offers clear and complete coverage of seismology, geodesy, gravimetry, magnetotellurics and related areas in the adjacent disciplines of physics, geology, oceanography and space science.
Download or read book Treatise on Geophysics Volume 7 written by David Bercovici and published by Elsevier. This book was released on 2010-05-17 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: Treatise on Geophysics: Mantle Dynamics, Volume 7 aims to provide both a classical and state-of-the-art introduction to the methods and science of mantle dynamics, as well as survey leading order problems (both solved and unsolved) and current understanding of how the mantle works. It is organized around two themes: (1) how is mantle convection studied; and (2) what do we understand about mantle dynamics to date. The first four chapters are thus concerned with pedagogical reviews of the physics of mantle convection; laboratory studies of the fluid dynamics of convection relevant to the mantle; theoretical analysis of mantle dynamics; and numerical analysis and methods of mantle convection. The subsequent chapters concentrate on leading issues of mantle convection itself, which include the energy budget of the mantle; the upper mantle and lithosphere in and near the spreading center (mid-ocean ridge) environment; the dynamics of subducting slabs; hot spots, melting anomalies, and mantle plumes; and finally, geochemical mantle dynamics and mixing. Self-contained volume starts with an overview of the subject then explores each topic in detail Extensive reference lists and cross references with other volumes to facilitate further research Full-color figures and tables support the text and aid in understanding Content suited for both the expert and non-expert
Download or read book Joint Seismic and Mineral Physics Modeling of the Upper Mantle Beneath Western North America written by Xin Wan and published by . This book was released on 2008 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Constitution of the Earth s Interior written by J. Leliwa-Kopystynski and published by Elsevier. This book was released on 2016-07-29 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: Constitution of the Earth's Interior discusses the physical and evolutionary principles connecting various elements of the knowledge about structure and dynamics of the Earth's interior. This work is divided into eight chapters that primarily focus on the physical, chemical, and petrological state. This text contains general data on a general stationary model, which is described by equations of state combining the basic parameters, including pressure, temperature, density, gravity acceleration, and mineral composition within the Earth's interior. Considerable chapters concern the chemical and petrological composition of the matter in the Earth's interior. The remaining chapters describe models containing inhomogeneities used to illustrate processes connected with phase transitions. This book will be of great value to geologists, physicists, and researchers.
Download or read book Mantle Convection for Geologists written by Geoffrey F. Davies and published by Cambridge University Press. This book was released on 2011-02-03 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mantle convection is the fundamental agent driving many of the geological features observed at the Earth's surface, including plate tectonics and plume volcanism. Yet many Earth scientists have an incomplete understanding of the process. This book describes the physics and fluid dynamics of mantle convection, explaining what it is, how it works, and how to quantify it in simple terms. It assumes no specialist background: mechanisms are explained simply and the required basic physics is fully reviewed and explained with minimal mathematics. The distinctive forms that convection takes in the Earth's mantle are described within the context of tectonic plates and mantle plumes, and implications are explored for geochemistry and tectonic evolution. Common misconceptions and controversies are addressed - providing a straightforward but rigorous explanation of this key process for students and researchers across a variety of geoscience disciplines.
Download or read book The Lithosphere written by Irina Artemieva and published by Cambridge University Press. This book was released on 2011-07-28 with total page 795 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting a coherent synthesis of lithosphere studies, this book covers a range of geophysical methods (seismic reflection, refraction, and receiver function methods; elastic and anelastic seismic tomography; electromagnetic and magnetotelluric methods; thermal, gravity and rheological models), complemented by petrologic and laboratory data on rock properties. It also provides a critical discussion of the uncertainties, assumptions, and resolution issues that are inherent in the different methods and models of the lithosphere. Multidisciplinary in scope, global in geographical extent, and covering a wide variety of tectonics settings across 3.5 billion years of Earth history, this book presents a comprehensive overview of lithospheric structure and evolution. It is a core reference for researchers and advanced students in geophysics, geodynamics, tectonics, petrology, and geochemistry, and for petroleum and mining industry professionals.
Download or read book Treatise on Geophysics written by and published by Elsevier. This book was released on 2015-04-17 with total page 5604 pages. Available in PDF, EPUB and Kindle. Book excerpt: Treatise on Geophysics, Second Edition, is a comprehensive and in-depth study of the physics of the Earth beyond what any geophysics text has provided previously. Thoroughly revised and updated, it provides fundamental and state-of-the-art discussion of all aspects of geophysics. A highlight of the second edition is a new volume on Near Surface Geophysics that discusses the role of geophysics in the exploitation and conservation of natural resources and the assessment of degradation of natural systems by pollution. Additional features include new material in the Planets and Moon, Mantle Dynamics, Core Dynamics, Crustal and Lithosphere Dynamics, Evolution of the Earth, and Geodesy volumes. New material is also presented on the uses of Earth gravity measurements. This title is essential for professionals, researchers, professors, and advanced undergraduate and graduate students in the fields of Geophysics and Earth system science. Comprehensive and detailed coverage of all aspects of geophysics Fundamental and state-of-the-art discussions of all research topics Integration of topics into a coherent whole
