Download or read book Synthesis of Regional Crust and Upper mantle Structure from Seismic and Gravity Data written by Shelton S. Alexander and published by . This book was released on 1982 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Earth s Crust and Upper Mantle written by Pembroke J. Hart and published by American Geophysical Union. This book was released on 1969 with total page 801 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1987 with total page 1124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Structure of the Earth s Crust written by Stephan Mueller and published by Elsevier Science & Technology. This book was released on 1974 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Earth s Crust and Mantle written by Raisa Mikhaĭlovna Demenit︠s︡kai︠a︡ and published by . This book was released on 1970 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: The translation is a summary of complex data on the earth's crust and upper mantle. In the examination of the data on the various regions of the terrestrial globe (characteristics of the gravity, magnetic, seismic, thermal and electric fields of the earth) and the comparison between them and the structure of the crust, the author reveals the specific features of the different geological structures and determines the diagnostic significance of the geophysical data. Much attention is given to the crustal structure of the oceanic areas. A description of the general characteristics of the relief and the physical properties of the upper mantle is given in the last section of the book, where the physical map of the upper mantle is given in the last section of the book, where the physical map of the upper mantle is presented. In conclusion, a review is given of the projects of ultradeep scientific boring in the Pacific ocean, territory of the USSR, Japan and Canada. (Author).
Download or read book Crustal and Uppermost Mantle Structure Beneath the Western United States from USArray Regional Phase Analysis written by Janine Sylvia Buehler and published by . This book was released on 2013 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this dissertation is to improve our understanding of the crust and uppermost mantle structure in the western United States, profiting from the wealth of regional phase data recorded at USArray stations. USArray, a transportable seismic array of ~400 seismometers, has greatly increased seismic data coverage across the United States in the past few years, and allows imaging of the lithosphere of the North American continent with better resolution and new methods. The regional phases are often challenging to analyze, especially in a tectonically-active region like the western United States, because of their sensitivities to the heterogeneities of the crust and uppermost mantle. However, knowledge of the seismic structure of the lithosphere is not only essential in order to accurately image the velocity structure at greater depths, but also for constraining geodynamic models that reconstruct the tectonic evolution of the continent, and hence the information that is carried by the regional phases is very valuable. The data set used in this study consists mostly of the regional seismic phases Pn and Sn, which propagate horizontally along the Moho in the mantle lid and constrain the seismic velocity structure at a confined depth. We applied traditional tomographic methods that profit from the improved ray coverage through USArray, but also employed array-based techniques that take advantage of the regular station spacing of the transportable array and don't depend on regularization. In addition, we used stacking methods to image the propagation efficiency of the Sn phase, which is often highly attenuated in tectonically active regions, on a regional scale. The results complement other seismic studies that average over greater depth intervals, such as surface- and body-wave tomographies and anisotropy analysis from shear-wave splitting, to provide information on temperature, composition, and tectonic processes at depth. Comparisons between Pn azimuthal anisotropy and fast polarization direction from shear wave splitting suggest significant vertical changes in anisotropy in several regions of the upper mantle beneath the western United States. Sn can in theory further constrain the nature of anisotropy in the mantle lid. However, we have so far been unable to resolve shear-wave splitting directly in the Sn waveforms as the phase is often attenuated and difficult to detect. Still, we obtained evidence for Sn propagation in several regions of the western United States such as the central Great Basin and the northeastern part of the Colorado Plateau. We found that there are enough quality Sn picks for joint Pn-Sn tomography and identified prominent Vp/Vs anomalies, such as large high Vp/Vs regions --- typically associated with partial melt --- below the Snake River Plain and the Colorado Plateau.
Download or read book Earth Resources written by and published by . This book was released on 1983 with total page 758 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Structure of the Earth s Crust and Upper Mantle from the Data of Seismic Investigations written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1988 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Continental Intraplate Earthquakes written by Seth Stein and published by Geological Society of America. This book was released on 2007-01-01 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This volume brings together a sampling of research addressing issues of continental intraplate earthquakes, including a core of papers from special sessions held at the spring 2004 Joint Assembly of the American and Canadian Geophysical Unions in Montreal. Papers address the broad related topics of the science, hazard, and policy issues of large continental intraplate earthquakes in a worldwide context. One group of papers addresses aspects of the primary scientific issue--where are these earthquakes and what causes them? Answering this question is crucial to determining whether they will continue there or migrate elsewhere. A second group of papers addresses the challenge of assessing the hazard posed by intraplate earthquakes. Although it may be a very long time before the scientific issues are resolved, the progress being made is helping attempts to estimate the probability, size, and shaking of future earthquakes, and the uncertainty of the results. A third group of papers explores the question of how society should mitigate the possible effects of future large continental intraplate earthquakes. Communities around the world face the challenge of deciding how to address this rare, but real, hazard, given the wide range of other societal needs. Continental intraplate earthquakes will remain a challenge to seismologists, earthquake engineers, policy makers, and the public for years to come, but significant progress toward understanding and addressing this challenge is now being made."--Publisher's website.
Download or read book The Upper Mantle written by A. R. Ritsema and published by Elsevier. This book was released on 2013-10-22 with total page 657 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developments in Geotectonics, 4: The Upper Mantle focuses on the upper mantle and its influence on the development of the earth's crust, including history of the moon and other planets and volcanology. The selection first offers information on the origin of the earth, including ideas on the formation process of the terrestrial planets, condensation of dust particles, nature of the earth's core, thermal history of the earth, and fractionation of iron in the terrestrial planets. The text then ponders on the beginning of continental evolution, as well as the oldest rocks of the earth's crust, thermal history of the moon, and early history of the other planets. The text elaborates on magmatic activity as the major process in the chemical evolution of the earth's crust and mantle; trends in the evolution of continents; progress and problems in volcanology; and pressure and temperature conditions and tectonic significance of regional and ocean-floor metamorphism. The manuscript also takes a look at the state of mantle minerals, melting temperatures in the earth's mantle, and geomagnetic induction studies and the electrical state of the upper mantle. The publication is a dependable reference for readers interested in the study of the upper mantle.
Download or read book Earth Resources written by and published by . This book was released on 1984 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International Aerospace Abstracts (IAA).
Download or read book NASA s University Program written by United States. National Aeronautics and Space Administration. Office of University Affairs and published by . This book was released on with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Part 1 A Regional Analysis of Crustal Structure in North America and Part 2 A Study of the Problems Associated with the Prediction of Gravity in Europe written by George Prior Woollard and published by . This book was released on 1969 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report is contained in two parts. Part I is an analysis of present gravity prediction procedures in the light of geophysical data concerning the crust and upper mantle. The assumptions on which these procedures are based (areas in isostatic equilibrium, relationship between Bouguer values and elevation, secondary control of Bouguer values, effects of near surface changes in geology) and their effects are discussed. Part II analyses the problems of predicting gravity in Europe. The geophysical factors related to these problems (a continental block bounded by deep water, intense tectonic deformation, acid and basic intrusives, lack of seismic measurements, glacial loading) are reviewed and the results tabulated. (Author).
Download or read book Structure of the Earth s Crust and Upper Mantle Plotted from the Data of Seismic Studies written by and published by . This book was released on 1978 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crustal Structure from In Country and Ground Truth Data written by and published by . This book was released on 2009 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: We are investigating the crustal and upper mantle structure of the region in central Asia bounded approximately by longitude 41-67 deg E and latitude 20-44 deg N by using in-country datasets of seismic phase arrival times, supplemented by ground truth datasets developed from our previous research efforts. We present the results of Pn tomography using a dataset consisting entirely of GT5 events in the region. From 27 calibrated earthquake clusters we extract 832 events that qualify as ground truth (GT)5 at the 90% confidence level. The raypaths of Pn readings from these events provide good coverage of most of the region except for the Makran region in the southeast. To determine an appropriate reference model for the region we compared empirical travel times calculated from the GT5 dataset to those predicted by several models: the ak135 global model (Kennett et al., 1995), the CUB2.0 model (Ritzwoller et al., 2003), and the so-called "Unified" model a 3-D velocity model of the crust and upper mantle in Eurasia, constructed from models developed by researchers at Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory (LANL) (Pasyanos et al, 2004; Begnaud et al., 2004; Steck et al., 2004; Flanagan et al., 2007). Although the CUB2.0 and Unified models do vary laterally, in the study region they vary quite slowly and capture little of the variability of observed travel times. All three models predict Pn travel times that are systematically too fast. These baseline errors range from 2-4 seconds. For this initial round of tomography we stretched the ak135 model to a crustal thickness of 45 km for the reference model.
Download or read book NASA s University Program Active Projects written by and published by . This book was released on 1981 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:
