Download or read book Regional Seismic Event Identification and Improved Locations with Small Arrays and Networks written by and published by . This book was released on 1995 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: This final report contains a summary of our work on the use of seismic networks and arrays to improve locations and identify small seismic event. The research can be divided into three main areas. We have developed techniques to migrate 3-component array records of local, regional and teleseismic wavetrains to directly image buried two- and three-dimensional heterogeneities (e.g. layer irregularities, volumetric heterogeneities) in the vicinity of the array. The initial intent of this research effort was to identify noise sources excited by incident signals and isolate their contributions to seismic coda. This technique has been applied to small-aperture array data collected in southern California. We have developed a technique to empirically characterize local and regional seismic code by binning and stacking network recordings of dense aftershock sequences. The principle motivation for this work was to look for robust coda phases dependent on source depth. We've used these empirical results, obtained by examining ANZA network recordings of Lande and Superstition Hills aftershocks, and have developed a technique to constrain sour depth. We have extended our ripple-fired event discriminant (based on the time-independence of coda produced by ripple firing) by looking for an independence of the coda from the recording direction (also indicative of ripple-firing). (MM).
Download or read book Regional Seismic Event Identification and Improved Locations With Small Arrays written by and published by . This book was released on 1998 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: We isolated the effect of structure immediately beneath seismic stations on seismic waveforms by determining the inference of velocity discontinuities beneath a single broadband 3-component seismic station using receiver functions, in which the P-to-S converted phases generated beneath a seismic station are isolated by deconvolution of the horizontal component seismograms by the vertical. We improve the deconvolution itself by the development of a time domain inversion for the receiver function. We extend the technique's application to an area of complex structure, using data collected at Pinon Flat Observatory, California, where we improve understanding of the region's structure and tectonic framework. We then used near-receiver- scattered component of teleseismic code to calibrate site amplifications for the southern California seismic network. We also developed and applied appropriate statistical analysis tools to permit accurate estimation of the site amplifications from the doubly censored non-Gaussian data. The main purpose of estimating site amplifications has been to enable isolation of propagation effects on Lg amplitudes, which is important to understand for accurate monitoring of nuclear testing. We conclude with the application of the site amplifications to Lg of regional events, demonstrating that they are successful in isolating propagation from site effects on Lg amplitudes.
Download or read book Detection Location and Identification of Regional Seismic Events Using a Small Broadband Array written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A seismic array combining short period and broadband instruments is being installed in the U.S. Pacific Northwest at the location of the former VELA array BMO (Blue Mountains Observatory, Oregon). No inventions were developed in the course of the work for this project.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Regional Small Event Identification Using Seismic Networks and Arrays written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report reviews our AFTAC funded research over the last two years. The principal objective of our research was to investigate the utility of time varying spectral estimates obtained from regional seismic records for distinguishing mining events from single explosions and earthquakes. A second goal of this research program was the exploration of additional small-event discrimination techniques which might be merged with the time-frequency method. The emphasis was on acoustic and low-frequency seismic techniques.
Download or read book Regional Small Event Identification Using Networks and Arrays of Seismic and Acoustic Sensors written by and published by . This book was released on 2006 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our work under this contract has had three primary objectives, but with the common theme of using seismic data to distinguish mining blasts from all other event types. We have used spectral characteristics of whole waveforms to discriminate industrial blasts from instantaneous explosions and earthquakes. We applied the automated time-frequency discriminant (AFTD) to several datasets to test transportability and robustness of the algorithm. The main conclusions of this work, described in the first section of this report, are that the method can be applied without significant modifications to broadly distributed datasets, but the method has limited range due to attenuation. In the second section, we describe our use of seismic waveforms between .05 and 10 Hz to characterize well ground-truthed mine blasts in Wyoming. Included in this section is preliminary modeling of events in this region. The report's third section summarizes the main findings of a review article written by Brian Stump, the PI, Craig Pearson and Vindell Hsu and published in the Reviews of Geophysics [4O(4), 1011, doi:l0.1029/ 1998 RGOOOO48, 2002]. In this article, we assess the state-of-the-art in global monitoring of mining blast activity and explore avenues for further research needed in this area.
Download or read book Integrated Seismic Event Detection and Location by Advanced Array Processing written by and published by . This book was released on 2007 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: The principal objective of this two-year study is to develop and test a new advanced, automatic approach to seismic detection/location using array processing. We address a strategy to obtain significantly improved precision in the location of low-magnitude events compared with current fully-automatic approaches, combined with a low false alarm rate. We have developed and evaluated a prototype automatic system which uses as a basis regional array processing with fixed, carefully calibrated, site-specific parameters in conjuction with improved automatic phase onset time estimation. We have in parallel developed tools for Matched Field Processing for optimized detection and source-region identification of seismic signals. This narrow-band procedure aims to mitigate some of the causes of difficulty encountered using the standard array processing system, specifically complicated source-time histories of seismic events and shortcomings in the plane-wave approximation for seismic phase arrivals at regional arrays.
Download or read book Proposals to Ban Nuclear Testing written by United States. Congress. House. Committee on Foreign Affairs and published by . This book was released on 1985 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Congressional Record written by United States. Congress and published by . This book was released on 1971 with total page 1226 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Developments in Technical Capabilities for Detecting and Identifying Nuclear Weapons Tests written by United States. Congress. Joint Committee on Atomic Energy and published by . This book was released on 1963 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Testing Moratorium Act S 2064 and Other Nuclear Testing Issues written by United States. Congress. Senate. Committee on Foreign Relations and published by . This book was released on 1992 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Documents on Disarmament written by United States. Arms Control and Disarmament Agency and published by . This book was released on 1986 with total page 896 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Documents on Disarmament written by and published by . This book was released on 1986 with total page 906 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ERDA Energy Research Abstracts written by and published by . This book was released on 1983 with total page 1144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Frontiers in Integrated Solid Earth Sciences written by S.A.P.L. Cloetingh and published by Springer Science & Business Media. This book was released on 2009-12-01 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Man’s intensifying use of the Earth’s habitat has led to an urgent need for scientifically advanced ‘geo-prediction systems’ that accurately locate subsurface resources and forecast the timing and magnitude of earthquakes, volcanic eruptions and land subsidence. As advances in the earth sciences lead to process-oriented ways of modeling the complex processes in the solid Earth, the papers in this volume provide a survey of some recent developments at the leading edge of this highly technical discipline. The chapters cover current research in predicting the future behavior of geologic systems as well as the mapping of geologic patterns that exist now in the subsurface as frozen evidence of the past. Both techniques are highly relevant to humanity’s need for resources such as water, and will also help us control environmental degradation. The book also discusses advances made in seismological methods to obtain information on the 3D structure of the mantle and the lithosphere, and in the quantitative understanding of lithospheric scale processes. It covers recent breakthroughs in 3D seismic imaging that have enhanced the spatial resolution of these structural processes, and the move towards 4D imaging that measures these processes over time. The new frontier in modern Earth sciences described in this book has major implications for oceanographic and atmospheric sciences and our understanding of climate variability. It brings readers right up to date with the research in this vital field.
Download or read book Advances in Seismic Event Location written by Cliffort H. Thurber and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 271 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Seismic Event Location provides a broad overview of the fundamental issues involved in seismic event location, and presents a variety of state-of-the-art location methods and applications at a wide range of spatial scales. Three important themes in the book are: seismic monitoring for a Comprehensive Nuclear-Test-Ban Treaty (CTBT), seismic event location in three-dimensional Earth models, and methods for multiple-event location. Each chapter contains background material to help readers less familiar with the topics covered, as well as to provide abundant references for readers interested in probing deeper into a topic. However, most of the emphasis is on recent advances in methodology and their application. Audience: The book is intended primarily for academic and professional researchers and graduate students in seismology.
