| Comprehensive Nuclear-Test-Ban Treaty: Updated 'Safeguards' and Net Assessments |
03-Jun-2009 |
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| Authors:
Jonathan Medalia; LIBRARY OF CONGRESS WASHINGTON DC CONGRESSIONAL RESEARCH SERVICE
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 | Limitations on nuclear testing have been on the international agenda since 1954. The United States ratified one such treaty in 1963 and two in 1990 that together bar all but underground nuclear tests with an explosive yield of 150 kilotons or less. The United States has observed a unilateral moratorium on nuclear tests since 1992. In 1996, this nation signed the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which would ban all nuclear ... |
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| Synthetic Seismogram Study of the Eastern Central Andes |
30-Sep-2008 |
9 pages |
| Authors:
Estela Minaya; Evanz Lazaro; Percy Aliaga; Magaly Gonzalez; Wilfredo Cano; OBSERVATORIO SAN CALIXTO LA PAZ (BOLIVIA)
|
 | Along the South American coast, there have been several earthquakes of great magnitude--between 7.5 and 9.5 Mw, with ruptures 50 km to 950 km long, producing maximum intensities between VII and X (MM)-particularly in two seismic gaps located in southern Peru and northern Chile. In these places, two large earthquakes occurred in the 19th century, in 1868 and in 1877, establishing the possibility of the seismic gap hypothesis: earthquake hazard ... |
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| Geochemical Characterization of Concentrated Gas Hydrate Deposits on the Hikurangi Margin, New Zealand: Preliminary Geochemical Cruise Report |
29 FEB 2008 |
44 pages |
| Authors:
Richard B. Coffin; LeiLa Hamdan; John Pohlman; Warren Wood; Ingo Pecher; Stuart Henrys; Jens Greinert; Kevin Faure; Andrew Gorman; Alan Orpin; NAVAL RESEARCH LAB WASHINGTON DC CHEMISTRY DIV
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| This report provides a preliminary summary of geochemical contribution to methane hydrate research and exploration on the Hikurangi Margin, off the northeastern coast of New Zealand from June 20 to July 3, 2006. Geochemical porewater profiles taken from shallow piston cores and vertical fluid migration measured with heatflow probing were compared with seismic summaries of potential deep sediment hydrates deposits. Research goals for this expedition include: (1) Refine geophysical, geochemical, ... |
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| Marine Seismic Surveys with Vector Acoustic Sensors |
01 OCT 2006 |
6 pages |
| Authors:
Dennis Lindwall; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS SEAFLOOR SCIENCES DIRECTORATE
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| Vector acoustic data will allow accurate three-dimensional imaging of a complex environment while corresponding pressure hydrophone data will fail. Newly developed sensors make vector acoustic-based surveys practical. This concept is demonstrated with data from an acoustic water tank. Using a simple but novel imaging algorithm, all of the main structures in the water tank were correctly located. This imaging algorithm uses none of the existing imaging or inversion methods common ... |
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| Acoustic/Seismic Ground Sensors for Detection, Localization and Classification on the Battlefield |
01 OCT 2006 |
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| Authors:
Alain Lemer; Frederique Ywanne; THALES UNDERWATER SYSTEMS SOPHIA-ANTIPOLIS (FRANCE)
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| The purpose of this paper is to present different acoustic and/or seismic systems designed and tested by Thales Underwater Systems (TUS) in the past few years, in order to detect, localize and classify a large panel of targets on the battlefield. The presented systems address mainly weapon fire detection and localisation, wheeled and tracked vehicles detection/localisation/tracking and aircraft (helicopters, drones) detection, localisation and classification. Depending on the application requirements, they ... |
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| Evidence for an Infrasound Waveguide |
NOV 2005 |
8 pages |
| Authors:
Eugene Herrin; Tae Sung Kim; Brian Stump; SOUTHERN METHODIST UNIV DALLAS TX DEPTOF GEOLOGICAL SCIENCES
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| On May 30, 2005, eight strongly dispersed infrasound signals were recorded at one seismo-acoustic array in the Republic of Korea. Phase-matched filtering (Herrin & Goforth, 1977) and a forward modeling technique were used to determine the nature of the dispersion. The most likely explanation for these dispersed infrasound signals is that the dispersion is due to propagation down a low-velocity waveguide: This can be characterized as an ephemeral "SOFAR" layer ... |
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| Disparate Sensor Integration for CB Defense |
01 OCT 2005 |
42 pages |
| Authors:
William Underwood; Amnon Birenzvige; David Sickenberger; EDGEWOOD CHEMICAL BIOLOGICAL CENTER ABERDEEN PROVING GROUND MD
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| The briefing explains how researchers are assessing integrated information from acoustic, seismic, and intrusion sensors as well as cameras for use in making determination of bio/chemical attacks. A detection algorithm has been developed that has proven able to distinguish between high explosive and bio/chemical artillery round explosions. |
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| Characterization of Underwater Explosions by Spectral/Cepstral Analysis, Modeling and Inversion |
MAY 2005 |
129 pages |
| Authors:
ENSCO INC SPRINGFIELD VA
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| The Use of Hydroacoustic Phases for the Detection of Oceanic Events: Observations and Numerical Modeling |
JUL 2004 |
63 pages |
| Authors:
Catherine DE Groot-Hedlin; Donna Blackman; John Orcutt; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA
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| Hydroacoustic monitoring of the Comprehensive Nuclear Test Ban Treaty (CTBT) requires the ability to detect and locate phenomena that give rise to acoustic signals. An improved understanding of the coupling of seismic energy to acoustic energy is necessary to improve location estimates of earthquakes and volcanic eruptions. Using known variations in near-source bathymetry, the authors demonstrated that scattering of seismic to acoustic energy at a rough seafloor yields the approximate ... |
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| Asymmetric Tow System for Multiple Linear Seismic Arrays |
10 DEC 2003 |
15 pages |
| Authors:
Thomas J. Gieseke; DEPARTMENT OF THE NAVY WASHINGTON DC
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| An asymmetric towing system for towing multiple linear arrays includes a tow platform and a single composite tow cable extending from the tow platform and having the multiple linear arrays connected both mechanically and electrically thereto. The composite tow cable is shaped by a hard streamlined casing and houses a load-bearing cable for mechanical connection to each array and plural individual array connections for establishing electrical communication between each array ... |
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| Semiannual Technical Summary, 1 January - 30 June 2003 |
AUG 2003 |
105 pages |
| Authors:
Frode Ringdal; NORWEGIAN SEISMIC ARRAY (NORSAR) KJELLER
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| This report describes the research activities carried out at NORSAR under Contract No. F08650-01-0-0055 for the period 1 January - 30 June 2003. In addition, it provides summary information on operation and maintenance (O&M) activities at the Norwegian National Data Center (NDC) during the same period. Research activities described in this report, as well as transmission of selected data to the United States NDC, are funded by the United States ... |
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| Nonlinear Seismic Response of Asymmetric Structures |
JUL 2003 |
682 pages |
| Authors:
Jon F. Sfura; ENGINEER RESEARCH AND DEVELOPMENT CENTER CHAMPAIGN IL CONSTRUCTION ENGINEERING RESEARCH LAB
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| The purpose of this study was to investigate the nonlinear, inelastic response of one-story, symmetric- and asymmetric-plan structures to uniaxial and biaxial lateral earthquake ground motions. The investigation is a combined experimental and analytical program. Through the study, the lateral-torsional response of the system was studied for a range of system parameters with the goals of examining the adequacy of current building code torsional design assumptions and the ability of ... |
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| Discrimination, Detection, Depth, Location, and Wave Propagation Studies Using Intermediate Period Surface Waves in the Middles East, Central Asia, and the Far East |
JUL 2003 |
152 pages |
| Authors:
Anatoli L. Levshin; Michael H. Ritzwoller; COLORADO UNIV AT BOULDER DEPT OF PHYSICS
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| The objective of this research was to construct surface wave group velocity maps at intermediate periods for the Near East, Central Asia and the Far East and to estimate the possibility of using these maps to extract weak surface wave signals and measure their amplitude spectra. To reach these goals we acquired broadband digital records of more than 1600 events that occurred in and around Eurasia during the period 1976-1998 ... |
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| Mobile Source Development for Seismic-Sonar Based Landmine Detection |
JUN 2003 |
72 pages |
| Authors:
Douglas J. MacLean; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Landmines continue to be a threat to both military and civilian communities throughout the world. Current methods of detection, while better than nothing, could certainly be improved. Seismic SONAR is a promising new technology that may help save countless lives. The goal of this thesis was to advance Seismic SONAR development by introducing a mobile source which could be easily used in practical applications. A small tracked vehicle with dual ... |
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| A Procedure to Edit Deep-Towed Navigation Data (CD-ROM) |
28 FEB 2003 |
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| Authors:
Charles Megnin; Warren T. Wood; Dennis A. Lindwall; Joseph F. Gettrust; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS MARINE GEOSCIENCES DIV
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| ELECTRONIC FILE CHARACTERISTICS: 9,715 files; Adobe Acrobat (.PDF). PHYSICAL DESCRIPTION: 1 computer laser optical disc (CD-ROM); 4 3/4 in.; 550 MB. SYSTEMS DETAIL NOTE: IBM-clone PC-compatible. ABSTRACT: While data acquired from deep-towed seismic surveys offer the potential of greatly increased image resolution over the surface-towed approach, accurate positioning constitutes an important challenge which, if not performed accurately, could offset the benefits gained by the proximity between the source and the ... |
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| A Procedure to Edit Deep-Towed Navigation Data |
28 FEB 2003 |
37 pages |
| Authors:
Charles Megnin; Warren T. Wood; Dennis A. Lindwall; Joseph F. Gettrust; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS MARINE GEOSCIENCES DIV
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| While data acquired from deep-towed seismic surveys offer the potential of greatly increased image resolution over the surface-towed approach, accurate positioning constitutes an important challenge which, if not performed accurately, could offset the benefits gained by the proximity between the source and the ocean bottom. We present here a new procedure that optimally determines relay and receiver positions at all times, using the Long Baseline acoustic navigation system. Navigation and ... |
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| Semiannual Technical Summary, 1 July - 31 December 2002 |
FEB 2003 |
96 pages |
| Authors:
Frode Ringdal; ROYAL NORWEGIAN COUNCIL FOR SCIENTIFIC AND INDUSTRIAL RESEARCH KJELLER
|
| This report describes the research activities carried out at NORSAR under Contract No. F0865O-O1 -0-0055 for the period 1 July - 31 December 2002. In addition, it provides summary information on operation and maintenance (O&M) activities at the Norwegian National Data Center (NDC) during the same period Research activities described in this report, as well as transmission of selected data to the United States NDC, are funded by the United ... |
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| Networked Unattended Ground Sensor Fields: Tradeoff Study and Configuration Rules Methodology |
AUG 2002 |
68 pages |
| Authors:
Linda M. Lamm; Patrick J. Driscoll; Gregory A. Lamm; MILITARY ACADEMY WEST POINT NY DEPT OFSYSTEM ENGINEERING
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| As the Army transforms itself into the 21st century, a number of new requirements arise in response to the need for a lighter force that is more rapidly deployed. The concept of trading heavy forces for information requires a substantial increase in the need for situational awareness and use of sensor technologies for remote reconnaissance collection on the battlefield. High quality situation awareness can be achieved using various types of ... |
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| Semiannual Technical Summary, 1 January - 30 June 2002 |
AUG 2002 |
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| Authors:
Frode Ringdal; ROYAL NORWEGIAN COUNCIL FOR SCIENTIFIC AND INDUSTRIAL RESEARCH KJELLER
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| This report describes the research activities carried out at NORSAR under Contract No. F08650-01-0-0055 for the period 1 January-30 June 2002. In addition, it provides summary information on operation and maintenance (O&M) activities at the Norwegian National Data Center (NDC) during the same period. Research actvities described in this report, as well as transmission of selected data to the United States NDC, are funded by the United States Department of ... |
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| Detection, Location, and Identification of Regional Seismic Events Using a Small Broadband Array |
MAR 2002 |
52 pages |
| Authors:
James E. Zollweg; BOISE STATE UNIV ID DEPT OF GEOSCIENCES
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| 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. |
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| Seismic-Acoustic Hybrid Sensor & Its Applications |
25 FEB 2002 |
13 pages |
| Authors:
John Sledge; TEST WING ( 46TH) EGLIN AFB FL
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| The need for instrumentation to gather seismic-acoustic signatures under unusual conditions requires the use of low cost, simple design, and robust sensors. In some instances, the sensors must adapt and mold to the environmental medium to provide proper coupling for data collection purposes. This paper explains how the idea of a hybrid seismic-acoustic sensor originated and initially implemented. Testing shows the device performs as a seismic and acoustic signature-gathering sensor. ... |
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| Semiannual Technical Summary, 1 July - 31 December 2001 |
FEB 2002 |
129 pages |
| Authors:
Frode Ringdal; ROYAL NORWEGIAN COUNCIL FOR SCIENTIFIC AND INDUSTRIAL RESEARCH KJELLER
|
| This report describes the research activities carried out at NORSAR under contract F08650-01-C-0055 for the period 1 July-31 December 2001. In addition, it provides summary information on operation and maintenance (O&M) activities at the Norwegian National Data Center (NDC) during the same period. Research activities described in this report, as well as transmission of selected data to the United States NDC, are funded by the United States Department of Defense. ... |
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| Enhanced Equipment for Acoustic Detection of Buried Landmines |
12 NOV 2001 |
4 pages |
| Authors:
James M. Sabatier; NATIONAL CENTER FOR PHYSICAL ACOUSTICS UNIVERSITY MS
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| Using funds provided by the Office of Naval Research, the University of Mississippi purchased three new laser Doppler vibrometers (LDVs) and upgraded an existing LDV for use in acoustic landmine detection research. |
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| Monte Carlo Simulation of Seismic Location Errors for Moving Vehicles |
04 OCT 2001 |
17 pages |
| Authors:
Roy J. Greenfield; M. L. Moran; PENNSYLVANIA STATE UNIV STATE COLLEGE
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| A method was developed to predict the distribution of seismic source mislocation errors for tracked vehicles using bearing and range (r) location statistics obtained from field data. The method is of use for 1) guiding the design and deployment of seismic sensor networks and 2) statistically modeling seismic network tracking performance. In the present work, a seismic array is composed of one or multiple seismic subarrays each of which makes ... |
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| Advanced Regional Array Studies |
SEP 2001 |
97 pages |
| Authors:
Tormod Kvaerna; NORWEGIAN SEISMIC ARRAY (NORSAR) KJELLER
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| We have addressed the problem of optimizing the site-specific seismic threshold monitoring method in order to achieve the highest possible automatic monitoring capability of particularly interesting areas, such as the Novaya Zemlya testing area, and the Indian and Pakistani test sites. For the Novaya Zemlya test site, where a regional monitoring network is available, we obtain a monitoring capability varying between m(sub b) 2.0 and 2.5 during normal noise conditions. ... |
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| Seismic Signature and Methodology Standard |
APR 2001 |
32 pages |
| Authors:
RANGE COMMANDERS COUNCIL WHITE SANDS MISSILE RANGE NM SIGNATURE MEASUREMENT STANDARDS GROUP
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| Seismic technology is a branch of the field of geophysics, the study of the earth using physical measurements at the surface. The geophysics, field employs many prospecting methods, including the following: seismic refraction; seismic reflection; gravitation; and magnetic, electrical, and radioactive anomalies. |
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| Detection and Feature Extraction of Mine-Like Objects from Seismic Sonar Signals |
MAR 2001 |
99 pages |
| Authors:
Craig A. Wilgenbusch; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| This thesis investigates detection and classification issues when dealing with seismic signals and represents a first step in the direction of automated detection and classification of mine-like signals obtained using a seismic approach. A computationally cheap detection scheme that utilizes a combination of a simple combination of a short- term energy and zero-crossing detector is implemented and tested on five different classes of targets, resulting in a 100% detection rate ... |
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| Methods for Improving Seismic Event Location Processing |
2001 |
11 pages |
| Authors:
Clifford H. Thurber; Wen-xuan Du; Haijiang Zhang; William J. Lutter; WISCONSIN UNIV-MADISON DEPT OF GEOLOGY AND GEOPHYSICS
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| Our research program consists of four components, each involving some aspect of multiple-event analysis: (1) high-precision waveform cross-correlation (WCC) for arrival time estimation, (2) robust event clustering, (3) waveform decomposition and source wavelet deconvolution reshaping, (4) double-difference (DD) multiple-event locations and tomography. Our research focused initially on the development and testing of these seismic analysis methods using 'ground- truth' (GT) datasets at different scales (local and regional), and is being ... |
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| Semiannual Technical Summary |
MAY 2000 |
137 pages |
| Authors:
Frode Ringdal; ROYAL NORWEGIAN COUNCIL FOR SCIENTIFIC AND INDUSTRIAL RESEARCH KJELLER
|
| This Semiannual Technical Summary describes the operation. maintenance and research activities at the Norwegian Seismic Array (NORSAR) the Norwegian Regional Seismic Array (NORES), the Arctic Regional Seismic Array (ARCES) and the Spitsbergen Regional Array for the period 1 October 1999-31 March 2000. Statistics are also presented for additional seismic stations, which through cooperative agreements with institutions in the host countries provide continuous data to ... |
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| Three Dimensional Finite-Difference Seismic Signal Propagation |
AUG 1999 |
14 pages |
| Authors:
mark Moran; Steve Ketcham; Roy Greenfield; COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH
|
| Moving tracked vehicles excite large-amplitude seismic surface waves that can be used to track and identify them at ranges over 1 km. Furthermore, these surface waves generally possess robust spatial coherence, show a smooth amplitude decay as a function vehicle range, and are minimally affected by severe meteorological conditions. Because of these properties, seismic signals should be used to augment acoustic sensing in battlefield systems. However, large changes in vehicle ... |
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| Characterization of Underground Facilities |
APR 1999 |
69 pages |
| Authors:
J. Cornwall; A. Despain; D. Eardley; R. Garwin; D. Hammer; MITRE CORP MCLEAN VA JASON PROGRAM OFFICE
|
| JASON undertook a study at DARPA's request to look for new opportunities for progress in the detection and characterization of UGFs. Part of our charge was to identify the most promising technology areas for investment, emphasizing standoff and covert sensor techniques. The study therefore surveyed a wide range of approaches, and we received numerous briefings. These included summaries of the technology programs of various agencies and briefings from organizations and ... |
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| Broadband Seismic Characterization of the Arabian Shield |
07 OCT 1998 |
46 pages |
| Authors:
Frank L. Vernon; Jonathan Berger; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA INST OF GEOPHYSICS AND PLANETARY PHYSICS
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| From November 1995 to March 1997 a total of nine broadband temporary stations were deployed across the Saudi Arabian shield. These stations consisted of STS-2 seismometers that recorded continuously at 40 sps on Refraction Technology RT72A-07 dataloggers. All installations were at bedrock sites. The results from our field deployment of nine portable broadband stations suggest that sites in the Arabian shield are extremely quiet with ground noise near or equal ... |
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| Semiannual Technical Summary |
OCT 1998 |
148 pages |
| Authors:
ROYAL NORWEGIAN COUNCIL FOR SCIENTIFIC AND INDUSTRIAL RESEARCH KJELLER
|
| This Semiannual Technical Summary describes the operation, maintenance and research activities at the Norwegian Seismic Array (NORSAR) the Norwegian Regional Seismic Array (NORESS), the Arctic Regional Seismic Array (ARCESS) and the Spitsbergen Regional Array for the period 1 April - 30 September 1998. Statistics are also presented for additional seismic stations, which through cooperative agreements with institutions in the host countries provide continuous data to the NORSAR Data processing Center ... |
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| Broadband Signal Enhancement of Seismic Array Data: Application to Long-Period Surface Waves and High-Frequency Wavefields |
27 JAN 98 |
6 pages |
| Authors:
Gary L. Pavlis; INDIANA UNIV BLOOMINGTON DEPT OF GEOLOGICAL SCIENCES
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| The original main goals of this project were twofold: (1) development of new techniques for enhancement of low signal to noise surface wave signals recorded by broadband arrays, and (2) research on fundamental properties of high-frequency wavefields. Two peer reviewed papers and two annual symposium reports present our results on the first task. For the second we have two published peer reviewed papers, one of our ... |
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| The Application of Broadband Arrays and Networks to Seismic Monitoring of Uncalibrated Regions |
30 NOV 97 |
7 pages |
| Authors:
Thomas J. Owens; SOUTH CAROLINA UNIV COLUMBIA DEPT OF GEOLOGY
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| Temporary broadband networks are clearly an advantage to efforts to calibrate relatively unknown regions. Our results demonstrate the type of information that can be determined with this type of data. Students have participated in this effort supported by both the Parent Agreement and the AASERT supplement. AASERT funding has been the primary support for Ph.D. student Philip Crotwell, who is working on the Sn propagation studies outlined below. The discrimination ... |
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| Observations from T-Phases from Pacific Earthquake Events: Implications for Seismic/Acoustic Coupling |
12 NOV 97 |
33 pages |
| Authors:
Catherin DEGroot-Hedlin; John Orcutt; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA
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| This report presents the results of a study of the coupling of seismic energy to the SOFAR channel and the propagation of acoustic energy from source to receiver. The results of an investigation of T-phase amplitude level vs. earthquake magnitude are presented for events in the Pacific ocean. The poor correlation between these parameters suggests that the generation of detectable T-phases is dependent not only upon event magnitude and depth, ... |
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| Development of a Lithospheric Model and Geophysical Data Base for North Africa |
20 OCT 97 |
85 pages |
| Authors:
D. I. Doser; G. R. Keller; S. Harder; K. C. Miller; P. J. Dial; TEXAS UNIV AT EL PASO DEPT OF GEOLOGICAL SCIENCES
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| We have collected seismic, geologic gravity and other potential data to develop a model of North African lithosphere via an integrated approach. We have generated a Bouguer gravity map and modeled gravity data along 3 transects. Seismograms from Worldwide Standardized Seismograph Network Stations of magnitude greater than 4.9 earthquakes occurring within North Africa (1963-1988) have also been collected and digitized. The regional waveforms of these seismograms have been used to ... |
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| Advances in Numerical Methods |
SEP 97 |
65 pages |
| Authors:
Keith L. McLaughlin; B. Shkoller; D. E. Wilkins; T. G. Barker; MAXWELL TECHNOLOGIES INC SAN DIEGO CA
|
| This report summarizes work conducted over a two year period to improve numerical methods. The report has three main sections. Section 2 covers work on synthetics for layered earth models. Section 3 reports on three- dimensional (3D) elastic finite difference calculations and the relationship between one-dimensional (1D) (layered earth) and 3D laterally heterogeneous wavefields. Section 4 reports on development of a finite difference program to model the response of permeable ... |
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| Development of Discrimination, Detection, and Location Capabilities in Central and Southern Asia Using Middle-Period Surface Waves Recorded by a Regional Array |
10 JUN 1997 |
57 pages |
| Authors:
Anatoli L. Levshin; Michael H. Ritzwoller; COLORADO UNIV AT BOULDER DEPT OF PHYSICS
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| This report presents the results of a study of the dispersion characteristics of intermediate period broadband fundamental surface waves propagating across Central Asia, Western China, and parts of the Middle East. We present group velocity maps from 10 s to 40 s period for both Rayleigh and Love waves. Broadband waveform data from about 600 events from 1988 - 1995 recorded at 83 individual stations from several global and regional ... |
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| In Situ Geophysical Investigation to Evaluate Dynamic Soil Properties at Success Dam, California |
JUN 97 |
95 pages |
| Authors:
Jose L. Liopis; Landris T. Lee; Russell A. Green; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS GEOTECHNICAL LAB
|
| An in situ geophysical investigation was conducted at Success Dam, California, to determine the shear wave (S-wave) velocities of the dam and foundation. The S-wave values are used in conjunction with conventional field and laboratory soil testing methods to provide soil property values for an earthquake analysis of the dam and foundation. The investigation consisted of S- wave crosshole and S-wave and compression wave (P-wave) surface seismic refraction tests along ... |
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| Semiannual Technical Summary for Contract F08650-96-C-0001 (Royal Norwegian Council for Scientific and Industrial Research) |
MAY 97 |
121 pages |
| Authors:
ROYAL NORWEGIAN COUNCIL FOR SCIENTIFIC AND INDUSTRIAL RESEARCH KJELLER
|
| This Semiannual Technical Summary describes the operation, maintenance and research activities at the Norwegian Seismic Array (NORSAR) the Norwegian Regional Seismic Array (NORESS), the Arctic Regional Seismic Array (ARCESS) and the Spitsbergen Regional Array for the period for the period 1 October 1896 - 31 March 1897. Statistics are also presented for additional seismic stations, which through cooperative agreements with institutions in the host countries provide continuous data to the ... |
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| A Micromechanical Silicon Oscillating Accelerometer |
17 APR 97 |
105 pages |
| Authors:
Kevin A. Gibbons; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| This thesis describes the design and testing of a silicon oscillating accelerometer (SOA). The SOA is a silicon, micromechanical, oscillating beam accelerometer. The accelerometer is configured with two silicon tuning fork oscillators that are electrostatically driven and sensed in their out of phase vibrational resonance. The oscillators move on flexure beams which are configured to have one end anchored and the other end fixed to a shared seismic mass. When ... |
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| Seismic Sources and Structure in Iran and the Caucasus from Joint Seismic Program Array Data |
APR 97 |
47 pages |
| Authors:
Geoffrey A. Abers; KANSAS UNIV LAWRENCE DEPT OF GEOLOGY
|
| Recently deployed seismic networks and arrays along the southern Former Soviet Union are characterized, including aspects of wave propagation that affect their ability to detect signals from the Iranian Plateau and surrounding regions. Signals at the Caucasus Network (CNET, deployed 1992-1994) were strongly affected by attenuation along paths that transect the Caucasus or Iranian Plateau, unlike signals to the north. At long paths (5-25 degree) the Caucasus and Iranian Plateau, ... |
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| Modes, Rays and Scattering: A Basic Study of Seismic Wave Propagation at Regional Distances |
19 FEB 97 |
31 pages |
| Authors:
Guust Nolet; F. A. Dahlen; R. A. Phinney; PRINCETON UNIV NJ DEPT OF GEOLOGICAL AND GEOPHYSICAL SCIENCES
|
| The objective of this research was to systematically explore the attributes of the wave form Lg and related wave forms which are trapped in the crust. The different theoretical approximations used to characterize or to fully compute regional seismic waves were thoroughly investigated. Empirical classification of the behavior of Lg was achieved through waveform data analyses. The Kennett conjecture that Lg waves can be adequately described by multiple S energy ... |
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| Broadband Seismic Recordings of Mining Explosions and Earthquakes in South America |
FEB 97 |
28 pages |
| Authors:
Susan L. Beck; Terry C. Wallace; ARIZONA UNIV TUCSON DEPT OF GEOSCIENCES
|
| The signing of the CTBT creates the challenge of monitoring the globe to ensure that there is no nuclear weapons testing. This means that the International Monitoring System must detect, locate, and identify with a high degree of accuracy a large number of seismic events. Individual countries will need to evaluate the events and discriminate man-caused events from naturally occurring seismicity. In regions of high seismicity and mining, the task ... |
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| NORSAR. Semiannual Technical Summary, 1 Apr-30 Sep 96 |
NOV 96 |
161 pages |
| Authors:
ROYAL NORWEGIAN COUNCIL FOR SCIENTIFIC AND INDUSTRIAL RESEARCH KJELLER
|
| The NORSAR Detection Processing system has been operated throughout the period with an average uptime of 99.9%. A total of 2392 seismic' events have been reported in the NORSAR monthly seismic bulletin for April-September 1996. The performance of the continuous alarm system and the automatic bulletin transfer to AFTAC has been satisfactory. Processing of requests for full NORSAR and regional array data on magnetic tapes has progressed according to established ... |
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| Broadband Seismic Characterization of the Arabian Shield |
OCT 96 |
25 pages |
| Authors:
J. E. Zollweg; BOISE STATE UNIV ID DEPT OF GEOSCIENCES
|
| A temporary deployment of eight broadband seismographs in the Arabian Shield and one on the Arabian Platform has shown that the shield sites are among the quietest in the world, with noise levels generally only slightly above the low-noise model. Distinct path-related differences in the recording of regional events allow the assignment of general source regions upon mere visual examination of the recordings. To date, clear regional phase are observed ... |
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| Three Component Micro and Small Aperture Arrays and Local Networks in Noisy Environment. Development of Statistical Data Processing Techniques: Coherent Noise Suppression, Signal Azimuth and Apparent Velocity Estimation, Generic Automated Event Source Loc |
SEP 96 |
312 pages |
| Authors:
Alexander F. Kushnir; Andrey N. Gashin; Leonid M. Halkin; Victor M. Lapshin; Andrey D. Rasskazov; SYNAPSE SCIENCE CENTER MOSCOW (RUSSIA)
|
| Automatic discrimination of weak explosions and earthquakes at local distances is an important problem for CTBT monitoring in regions where commercial mining operations and quarry blasting generate a large number of seismic recordings on a daily basis. Development of reliable discrimination techniques to solve this problem involve selection of regionally dependent parameters (which have to be automatically extracted from seismograms) and estimation of misclassification probabilities intrinsic for a given region. ... |
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| High Resolution Intermediate Period (10-40 s) Group Velocity Variations Across Central Asia |
10 AUG 96 |
22 pages |
| Authors:
Anatoli L. Levshin; Michael H. Ritzwoller; COLORADO UNIV AT BOULDER DEPT OF PHYSICS
|
| This research is dedicated to investigating the relevance and use of intermediate period (10 - 40 s) surface wave data in problems of detection, discrimination, and the accurate location of small events using regional array data. It is focused on the analysis of data from events throughout Central and Southern Asia within 27 degrees of the Kyrgyz Telemetered Seismic Network. The main efforts during the 1 year time period covered ... |
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| Geophysical Investigation of Cluster 11, Edgewood Area, Aberdeen Proving Ground, Maryland |
MAR 96 |
138 pages |
| Authors:
Michael K. Sharp; Janet E. Simms; Landris T. Lee Jr.; Jerry L. Burgess; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS GEOTECHNICAL LAB
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| A geophysical investigation consisting of surface seismic, electric, electromagnetic, magnetic, and ground penetrating radar methods was conducted at the cluster 11 site located in the Edgewood Area of the Aberdeen Proving Ground, Maryland, The purpose of the investigation was to locate underground structures such as barrels and tanks. The results indicated the presence of unknown underground anomalies at each site, and their locations were mapped. |
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Reports by Keyword(s)
SEISMIC DETECTION
