Search Results

open access

2-D or not 2-D, that is the question: A Northern California test

Description: Reliable estimates of the seismic source spectrum are necessary for accurate magnitude, yield, and energy estimation. In particular, how seismic radiated energy scales with increasing earthquake size has been the focus of recent debate within the community and has direct implications on earthquake source physics studies as well as hazard mitigation. The 1-D coda methodology of Mayeda et al. has provided the lowest variance estimate of the source spectrum when compared against traditional approa… more
Date: June 6, 2005
Creator: Mayeda, K; Malagnini, L; Phillips, W S; Walter, W R & Dreger, D
Partner: UNT Libraries Government Documents Department
open access

2-D Path Corrections for Local and Regional Coda Waves: A Test of Transportability

Description: Reliable estimates of the seismic source spectrum are necessary for accurate magnitude, yield, and energy estimation. In particular, how seismic radiated energy scales with increasing earthquake size has been the focus of recent debate within the community and has direct implications on earthquake source physics studies as well as hazard mitigation. The 1-D coda methodology of Mayeda et al. [2003] has provided the lowest variance estimate of the source spectrum when compared against traditional… more
Date: July 13, 2005
Creator: Mayeda, K M; Malagnini, L; Phillips, W S; Walter, W R; Dreger, D S & Morasca, P
Partner: UNT Libraries Government Documents Department
open access

300-Area accident analysis for Emergency Planning Zones

Description: The Department of Energy has requested SRL assistance in developing offsite Emergency Planning Zones (EPZs) for the Savannah River Plant, based on projected dose consequences of atmospheric releases of radioactivity from potential credible accidents in the SRP operating areas. This memorandum presents the assessment of the offsite doses via the plume exposure pathway from the 300-Area potential accidents. 8 refs., 3 tabs.
Date: June 27, 1983
Creator: Pillinger, W.L.
Partner: UNT Libraries Government Documents Department
open access

2001 - 2002 Upper Three Runs Sequence of Earthquakes at the SRS, South Carolina

Description: On October 08, 2001 a small felt earthquake occurred near Upper Three Runs Creek in the north central area of the Savannah River Site, South Carolina. Seven very small aftershocks followed the main event with the last one occurring March 06, 2002. All activity occurred within a small area. Further analysis of collected data indicates a correlation of this low level seismic activity with a small northwest trending structure observed in detailed gravity and magnetic data. Both single event and co… more
Date: October 16, 2003
Creator: Stevenson, Donald A.
Partner: UNT Libraries Government Documents Department
open access

2012 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

Description: This Research is about Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies which presents a preliminary model of the three-dimensional seismic structure of the Iran region.
Date: September 10, 2012
Creator: Wetovsky, Marvin A.; Anderson, Dale; Arrowsmith, Stephen J.; Begnaud, Michael L.; Hartse, Hans E.; Maceira, Monica et al.
Partner: UNT Libraries Government Documents Department
open access

6th International Special Session on Current Trends in Numerical Simulation for Parallel Engineering Environments

Description: In today's world, the use of parallel programming and architectures is essential for simulating practical problems in engineering and related disciplines. Remarkable progress in CPU architecture (multi- and many-core, SMT, transactional memory, virtualization support, etc.), system scalability, and interconnect technology continues to provide new opportunities, as well as new challenges for both system architects and software developers. These trends are paralleled by progress in parallel algor… more
Date: July 9, 2007
Creator: Schulz, M & Trinitis, C
Partner: UNT Libraries Government Documents Department
open access

Acceleration amplifications in nif structures subjected to earthquake base motions

Description: NIF technical staff have questioned the possibility of obtaining acceleration amplifications (i.e. amplification of the ground acceleration values) in a structure which are significantly higher than the acceleration amplification exhibited across the period range in the input response spectrum. This note utilizes a simple example to illustrate that the acceleration amplification resulting from the dynamic response of a structural system can indeed be significantly higher than the amplifications… more
Date: November 29, 1999
Creator: McCallen, D.
Partner: UNT Libraries Government Documents Department
open access

Accident Fault Trees for Defense Waste Processing Facility

Description: The purpose of this report is to document fault tree analyses which have been completed for the Defense Waste Processing Facility (DWPF) safety analysis. Logic models for equipment failures and human error combinations that could lead to flammable gas explosions in various process tanks, or failure of critical support systems were developed for internal initiating events and for earthquakes. These fault trees provide frequency estimates for support systems failures and accidents that could lead… more
Date: June 22, 1999
Creator: Sarrack, A.G.
Partner: UNT Libraries Government Documents Department
open access

Acoustic Emission Precursors of M6.0 2004 Parkfield and M7.0 1989Loma Prieta Earthquakes

Description: Two recent strike-slip earthquakes on the San Andreas Fault(SAF) in California, the M6.0 2004 Parkfield and M7.0 1989 Loma Prietaevents, revealed peaks in the acoustic emission (AE) activity in thesurrounding crust several months prior to the main events. Earthquakesdirectly within the SAF zone were intentionally excluded from theanalysis. The observed increase in AE is assumed to be a signature of theincreasing stress level in the surrounding crust, while the peak andsubsequent decrease in AE … more
Date: February 1, 2005
Creator: Korneev, Valeri
Partner: UNT Libraries Government Documents Department
open access

Active And Passive Seismic Studies of Geothermal Resources in New Mexico and Investigations of Earthquake Hazards to Geothermal Development

Description: Seismic data were collected in southwestern New Mexico to investigate the sources of the geothermal anomalies and to investigate the potential earthquake hazards of geothermal development. No major crustal structure anomalies have been located related to known geothermal resources, and no areas of continual seismicity have been identified, which is interpreted to indicate a lack of active, or recently active crustal intrusions in southwestern New Mexico. Without a magnetic heat source, the geot… more
Date: January 1980
Creator: Morgan, Paul & Daggett, Paul H.
Partner: UNT Libraries Government Documents Department
open access

Active structural control by fuzzy logic rules: An introduction

Description: A zeroth level introduction to fuzzy logic control applied to the active structural control to reduce the dynamic response of structures subjected to earthquake excitations is presented. It is hoped that this presentation will increase the attractiveness of the methodology to structural engineers in research as well as in practice. The basic concept of the fuzzy logic control are explained by examples and by diagrams with a minimum of mathematics. The effectiveness and simplicity of the fuzzy l… more
Date: December 1996
Creator: Tang, Yu & Wu, Kung C.
Partner: UNT Libraries Government Documents Department
open access

Active structural control by fuzzy logic rules: An introduction

Description: An introduction to fuzzy logic control applied to the active structural control to reduce the dynamic response of structures subjected to earthquake excitations is presented. It is hoped that this presentation will increase the attractiveness of the methodology to structural engineers in research as well as in practice. The basic concept of the fuzzy logic control are explained by examples and by diagrams with a minimum of mathematics. The effectiveness and simplicity of the fuzzy logic control… more
Date: July 1, 1995
Creator: Tang, Y.
Partner: UNT Libraries Government Documents Department
open access

Active vibration control of civil structures

Description: This is a final report of a one year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Active vibration control (AVC) of structural and mechanical systems is one of the rapidly advancing areas of engineering research. The multifaceted nature of AVC covers many disciplines, such as sensors and instrumentation, numerical modeling, experimental mechanics, and advanced power systems. This work encompassed a review of the literature on active … more
Date: November 1, 1996
Creator: Farrar, C.; Baker, W.; Fales, J. & Shevitz, D.
Partner: UNT Libraries Government Documents Department
open access

Addressing earthquake strong ground motion issues at the Idaho National Engineering Laboratory

Description: In the course of reassessing seismic hazards at the Idaho National Engineering Laboratory (INEL), several key issues have been raised concerning the effects of the earthquake source and site geology on potential strong ground motions that might be generated by a large earthquake. The design earthquake for the INEL is an approximate moment magnitude (M{sub w}) 7 event that may occur on the southern portion of the Lemhi fault, a Basin and Range normal fault that is located on the northwestern bou… more
Date: December 31, 1991
Creator: Wong, I. G.; Silva, W. J.; Stark, C. L.; Jackson, S. & Smith, R. P.
Partner: UNT Libraries Government Documents Department
open access

Addressing earthquake strong ground motion issues at the Idaho National Engineering Laboratory

Description: In the course of reassessing seismic hazards at the Idaho National Engineering Laboratory (INEL), several key issues have been raised concerning the effects of the earthquake source and site geology on potential strong ground motions that might be generated by a large earthquake. The design earthquake for the INEL is an approximate moment magnitude (M{sub w}) 7 event that may occur on the southern portion of the Lemhi fault, a Basin and Range normal fault that is located on the northwestern bou… more
Date: January 1, 1991
Creator: Wong, Ivan G.; Silva, Walter J.; Stark, Cathy L.; Jackson, Suzette & Smith, Richard P.
Partner: UNT Libraries Government Documents Department
open access

ADVANCED WAVEFORM SIMULATION FOR SEISMIC MONITORING EVENTS

Description: Comprehensive test ban monitoring in terms of location and discrimination has progressed significantly in recent years. However, the characterization of sources and the estimation of low yields remains a particular challenge. As the recent Korean shot demonstrated, we can probably expect to have a small set of teleseismic, far-regional and high-frequency regional data to analyze in estimating the yield of an event. Since stacking helps to bring signals out of the noise, it becomes useful to con… more
Date: July 16, 2007
Creator: Helmberger, D; Tromp, J & Rodgers, A
Partner: UNT Libraries Government Documents Department
open access

ADVANCED WAVEFORM SIMULATION FOR SEISMIC MONITORING EVENTS

Description: The recent Nevada Earthquake (M=6) produced an extraordinary set of crustal guided waves. In this study, we examine the three-component data at all the USArray stations in terms of how well existing models perform in predicting the various phases, Rayleigh waves, Love waves, and Pnl waves. To establish the source parameters, we applied the Cut and Paste Code up to distance of 5° for an average local crustal model which produced a normal mechanism (strike=35°,dip=41°,rake=-85°) at a depth of 9 k… more
Date: April 15, 2008
Creator: Helmberger, Donald V.; Tromp, Jeroen & Rodgers, Arthur J.
Partner: UNT Libraries Government Documents Department
open access

Advanced Waveform Simulation for Seismic Monitoring Events

Description: Abstract We conduct a detailed test of a recently developed technique, CAPloc, in recovering source parameters from a few stations against results from a large broadband network in Southern California. The method uses a library of 1D Green’s functions which are broken into segments and matched to waveform observations with adjustable timing shifts. These shifts can be established by calibration against a distribution of well-located earthquakes and assembled in tomographic images for predicting… more
Date: January 27, 2009
Creator: Helmberger, Donald V.; Tromp, Jeroen & Rodgers, Arthur J.
Partner: UNT Libraries Government Documents Department
open access

ADVANCED WAVEFORM SIMULATION FOR SEISMIC MONITORING EVENTS - REPORTING PERIOD AUGUST 1, 2007-OCTOBER 31, 2007

Description: We have developed a forward modeling technique to retrieve rupture characteristics of small earthquakes (3<M<5), including rupture propagation direction, fault dimension, and rupture speed.
Date: September 30, 2007
Creator: Helmberger, Donald V.; Tromp, Jeroen & Rodgers, Arthur J.
Partner: UNT Libraries Government Documents Department
open access

ADVANCED WAVEFORM SIMULATION FOR SEISMIC MONITORING EVENTS; REPORTING PERIOD NOVEMBER 1, 2006 - JANUARY 31, 2007

Description: The amplitude fluctuations of seismic waves from point source radiation patterns are among the direct results of rupture propagation. However, these amplitude signals are seldom used for small earthquakes due to the large uncertainties in the focal mechanisms of the events or the empirical Green’s functions (EGFs). Moreover, it has been controversial if radiation patterns still exist at high frequencies, e.g., 10 Hz. We present an evidence for high frequency radiation patterns by showing that w… more
Date: January 31, 2007
Creator: Helmberger, Donald V.; Tromp, Jeroen & Rodgers, Arthur J.
Partner: UNT Libraries Government Documents Department
open access

Advisability of seismic scram

Description: The study assesses the value of seismic trip (scram) systems on commercial nuclear power plants. Five topics were specifically addressed: (1) the likelihood that existing instrumentation would trip the plant; (2) the consequences of spurious trips; (3) the consequences of tripping during an earthquake; (4) the advantages of a controlled shutdown; and (5) the desirability of continuing operation. A comparative risk assessment was made based on evaluation of fault trees constructed for plants wit… more
Date: June 30, 1976
Creator: Cummings, G. E.; Wells, J. E.; Lambert, H. E. & Leger-Barter, G. S.
Partner: UNT Libraries Government Documents Department
open access

The Affect of Realistic Geologic Heterogeneity on Local and Regional P/S Amplitude Ratios Based on Numerical Simulations

Description: Regional seismic discriminants based on high-frequency P/S ratios reliably distinguish between earthquakes and explosions. However, P/S discriminants in the 0.5 to 3 Hz band (where SNR can be highest) rarely perform well, with similar ratios for earthquake and explosion populations. Variability in discriminant performance has spawned numerous investigations into the generation of S-waves from explosions. Several viable mechanisms for the generation of S-waves from explosions have been forwarded… more
Date: July 11, 2005
Creator: Myers, S. C.; Wagoner, J. L.; Preston, L.; Smith, K. & Larsen, S. C.
Partner: UNT Libraries Government Documents Department
open access

Aftershock Characteristics as a Means of Discriminating Explosions from Earthquakes

Description: The behavior of aftershock sequences around the Nevada Test Site in the southern Great Basin is characterized as a potential discriminant between explosions and earthquakes. The aftershock model designed by Reasenberg and Jones (1989, 1994) allows for a probabilistic statement of earthquake-like aftershock behavior at any time after the mainshock. We use this model to define two types of aftershock discriminants. The first defines M{sub X}, or the minimum magnitude of an aftershock expected wit… more
Date: May 20, 2009
Creator: Ford, S R & Walter, W R
Partner: UNT Libraries Government Documents Department
open access

Los Alamos National Laboratory Northern New Mexico Seismic Network and seismicity

Description: The Northern New Mexico Seismic Network (NNMSN) is described and the research conducted there briefly discussed. Its purpose is to: (1) monitor seismic activity that can pose a risk to the Los Alamos National Laboratory; (2) monitor induced seismicity that might result from the Laboratory's experimental activities, such as the Hot Dry Rock project; (3) provide data for research in test ban verification; and (4) provide data for fundamental research in seismology, tectonics, and geologic structu… more
Date: January 1, 1981
Creator: Cash, Dan J.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen