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Building on and spinning off: Sandia National Labs` creation of sensors for Vietnam

Description: This paper discusses Sandia National Laboratories` development of new technologies for use in the Vietnam War - specifically the seismic sensors deployed to detect troop and vehicle movement - first along the Ho Chi Minh Trail and later in perimeter defense for American military encampments in South Vietnam. Although the sensor story is a small one, it is interesting because it dovetails nicely with our understanding of the war in Vietnam and its frustrations; of the creation of new technologies for war and American enthusiasm for that technology; and of a technological military and the organizational research and a m am development structure created to support it. Within the defense establishment, the sensors were proposed within the context of a larger concept - that of a barrier to prevent the infiltration of troops and supplies from North Vietnam to the South. All of the discussion of the best way to fight in Vietnam is couched in the perception that this was a different kind of war than America was used to fighting. The emphasis was on countering the problems posed by guerrilla/revolutionary warfare and eventually by the apparent constraints of being involved in a military action, not an outright war. The American response was to find the right technology to do the job - to control the war by applying a technological tincture to its wounds and to make the war familiar and fightable on American terms. And, when doubts were raised about the effectiveness of applying existing technologies (namely, the bombing of North Vietnam and Laos), the doubters turned to new technologies. The sensors that were developed for use in Vietnam were a direct product of this sort of thinking - on the part of the engineers at Sandia who created the sensors, the civilian scientific advisors who recommended ...
Date: December 31, 1996
Creator: Ullrich, R.
Partner: UNT Libraries Government Documents Department

Infrasonic signals from an accidental chemical explosion

Description: A series of large accidental explosions occurred at a chemical plant in Henderson, Nevada on May 4, 1988. The explosions were produced by the ignition of stores of ammonium perchlorate produced for solid rocket fuel at the Pacific Engineering and Production Co. This material, prior to the incident, had been believed to be non- explosive. The blasts destroyed the plant and caused one death. There was a series of explosions over a period of time with two major explosions which we will identify as A at 18:53:34 (all times herein will be given in C.U.T.) and B at 18:57:35. Signals from events A and B as well as smaller events were detected by the infrasound arrays operated by the Los Alamos National Laboratory at St. George, Utah (distance 159 km) and at Los Alamos, N.M. (distance 774 km). The Henderson explosions present an interesting and challenging set of infrasound observations. The case may be unique in providing two very large sources separated in time by only four minutes. To fully understand the propagation details will require further analysis and probably a modeling effort. The understanding of the St. George signals in the context of Lamb waves would be valuable for a better understanding of this mode of propagation. The improved understanding of long range infrasonic propagation is now especially important in the context of the Comprehensive Test Ban Treaty (CTBT). A portion of the plan for CTBT monitoring includes a global distribution of sixty infrasound arrays to provide for the monitoring of signals in as uniform a way as possible. It is expected that under this global network many signals and interpretation questions of the type described here will be encountered. Investigations of propagation over the ranges of hundreds to thousands of kilometers will be highly desired.
Date: December 31, 1996
Creator: Mutschlecner, J.P. & Whitaker, R.W.
Partner: UNT Libraries Government Documents Department

Regional observations of mining blasts by the GSETT-3 seismic monitoring system

Description: The cessation of testing of any nuclear explosive devices in all environments is the goal of the Comprehensive Test Ban Treaty. In order to assure compliance with such a treaty, an international monitoring system has been proposed. This system will include seismic, infrasound, hydroacoustic and radionuclide monitors located throughout the world. The goal of this system is the detection of any nuclear test. In preparation for this treaty, a series of monitoring system tests, focusing primarily on seismic observations, have been undertaken. The most recent of these tests, Group of Scientific Experts Technical Test Three (GSETT-3), provides valuable data for assessing future monitoring systems. During the course of this experiment, seismic events associated with earthquakes, nuclear explosions and mining explosions have been recorded. This presentation will discuss the numbers and types of mining explosions triggering the system, in a particular area. Possible implications for the mining industry will be explored.
Date: December 31, 1996
Creator: Stump, B.W. & Pearson, D.C.
Partner: UNT Libraries Government Documents Department

Infrasound workshop for CTBT monitoring: Proceedings

Description: It is expected that the establishment of new infrasound stations in the global IMS network by the Provisional Technical Secretariat of the CTBTO in Vienna will commence in the middle of 1998. Thus, decisions on the final operational design for IMS infrasound stations will have to be made within the next 12 months. Though many of the basic design problems have been resolved, it is clear that further work needs to be carried out during the coming year to ensure that IMS infrasound stations will operate with maximum capability in accord with the specifications determined during the May 1997 PrepCom Meeting. Some of the papers presented at the Workshop suggest that it may be difficult to design a four-element infrasound array station that will reliably detect and locate infrasound signals at all frequencies in the specified range from 0.02 to 4.0 Hz in all noise environments. Hence, if the basic design of an infrasound array is restricted to four array elements, the final optimized design may be suited only to the detection and location of signals in a more limited pass-band. Several participants have also noted that the reliable discrimination of infrasound signals could be quite difficult if the detection system leads to signal distortion. Thus, it has been emphasized that the detection system should not, if possible, compromise signal fidelity. This report contains the workshop agenda, a list of participants, and abstracts and viewgraphs from each presentation.
Date: November 1, 1998
Creator: Christie, D. & Whitaker, R.
Partner: UNT Libraries Government Documents Department

Testing the waveform correlation event detection system: Teleseismic, regional, and local distances

Description: Waveform Correlation Event Detection System (WCEDS) prototypes have now been developed for both global and regional networks and the authors have extensively tested them to assess the potential usefulness of this technology for CTBT (Comprehensive Test Ban Treaty) monitoring. In this paper they present the results of tests on data sets from the IDC (International Data Center) Primary Network and the New Mexico Tech Seismic Network. The data sets span a variety of event types and noise conditions. The results are encouraging at both scales but show particular promise for regional networks. The global system was developed at Sandia Labs and has been tested on data from the IDC Primary Network. The authors have found that for this network the system does not perform at acceptable levels for either detection or location unless directional information (azimuth and slowness) is used. By incorporating directional information, however, both areas can be improved substantially suggesting that WCEDS may be able to offer a global detection capability which could complement that provided by the GA (Global Association) system in use at the IDC and USNDC (United States National Data Center). The local version of WCEDS (LWCEDS) has been developed and tested at New Mexico Tech using data from the New Mexico Tech Seismic Network (NMTSN). Results indicate that the WCEDS technology works well at this scale, despite the fact that the present implementation of LWCEDS does not use directional information. The NMTSN data set is a good test bed for the development of LWCEDS because of a typically large number of observed local phases and near network-wide recording of most local and regional events. Detection levels approach those of trained analysts, and locations are within 3 km of manually determined locations for local events.
Date: August 1, 1997
Creator: Young, C.J.; Beiriger, J.I. & Harris, J.M.
Partner: UNT Libraries Government Documents Department

Regional characterization of Western China-II

Description: As part of the CTBT Research and Development regional characterization effort, geological, geophysical, and seismic data are being assembled and organized for inclusion in a knowledge base for China. The authors have continued their analysis using data form the station WMQ of the Chinese Digital Seismic Network (CDSN) and the IRIS station AAK. They are also acquiring and analyzing data from stations that are designated as (or near a designated) primary or secondary CTBT monitoring station. Regional seismograms are being analyzed to construct travel time curves, velocity models, attenuation characteristics, and to quantify regional propagation effects such as phase blockages. Using locations from the USGS Preliminary Determination of Epicenters (PDE) they have identified Pn, Pg, Sn, and Lg phases, constructed travel time curves, and estimated apparent velocities using linear regression. Amplitudes for the seismic phases have been measured using bandpassed waveforms and a series of magnitude relations have been determined for Western China. Studies of path specific propagation efficiency of the seismic phases have mapped blockages and also identified a possible set of observations that can be used to identify intermediate depth (> 100 im) seismic events in the Pamir-Hindu Kush seismic zone. Chinese seismicity catalogs from the USGS and Chinese State Seismological Bureau (SSB) are being used to identify and obtain seismic data (including mine seismicity) and information for lower magnitude events. Clustering analysis has been used to identify seismicity clusters in space with origin times that are distributed during daylight hours which suggest mining operations. These clusters are being investigated with imagery to attempt to identify precise mine locations.
Date: October 1, 1996
Creator: Randall, G.E.; Hartse, H.E.; Phillips, W.S. & Taylor, S.R.
Partner: UNT Libraries Government Documents Department

Mining industry and US government cooperative research: Lessons learned and benefits to mining industry

Description: Since 1994, various mines in the US have cooperated with research scientists at the Los Alamos and Lawrence Livermore National Laboratories to address issues related to verification of the Comprehensive Test Ban Treaty (CTBT). The CTBT requires that no country may conduct any nuclear explosion in the future. While the CTBT is a significant step toward reducing the global nuclear danger, verifying compliance with the treat requires that the monitoring system be able to detect, locate and identify much larger numbers of smaller amplitude seismic events than had been required previously. Large mining blasts conducted world-wide will be of sufficient amplitude to trigger the monitoring system at the lower threshold. It is therefore imperative that research into the range various blasting practices employed, the relationship of yield to seismic magnitude, and identification of anomalous blasting results be performed. This paper will describe a suite of experiments funded by the Department of Energy and conducted by the Los Alamos and Lawrence Livermore National Laboratories in cooperation with the US mining industry. Observations of cast blasting, underground long wall generated coal bumps, stoping, and explosively induced collapse of room and pillar panels will be presented. Results of these dual use experiments which are of interest to the mining community will be discussed. These include (1) variation of amplitude of seismic energy at various azimuths from cast blasts, (2) identification of the extent of back failure following explosive removal of pillars, and (3) the use of single fired shots for calibration of the monitoring system. The wealth of information and discovery described in this paper is a direct result of mutual cooperation between the US Government and the US Mining Industry.
Date: September 1, 1997
Creator: Pearson, D.C.; Stump, B.W.; Phillips, W.S.; Martin, R. & Anderson, D.P.
Partner: UNT Libraries Government Documents Department

The source depth of burial experiment at Shagan River, Kazakstan

Description: The seismic field experimentation team at Los Alamos National Laboratory collaborated with Lawrence Livermore, the Defense Special Weapons Agency (DSWA) and the National Nuclear Center of the Republic of Kazakstan to record the Source Depth of Burial Experiment during the summer of 1997. A series of three 25 ton explosions at depths of 50, 300 and 550 meters along with associated 50 to 100 kg Green`s function explosions and a 5 ton proof of concept explosion were instrumented at near source (0.1 to 20 km) and regional distances (100 to 1,100 km) using portable seismic data acquisition equipment. The near source data represent the first US recordings of seismic data at the former Soviet Union`s Semipalatinsk nuclear test site. The main objective of the Depth of Burial Experiment was to test whether source depth can help identify underground nuclear explosions from observations at distance ranges of 100--1,000 km. A secondary objective was to help calibrate the Kazakstan seismic network, especially the primary IMS station at Makanchi and the auxiliary IMS stations at Kurchatov and Aktyubinsk. Near-source records show the 50 m deep explosion generated much higher amplitude surface (R{sub g}) waves than did either of the deeper explosions. Impulse P-wave arrivals dominated the traces from the 300 and 550 meter deep explosions. P-wave amplitudes, 10--20 Hz, appeared to be a stronger function of source than of path or site. Apparent P velocity was highly path dependent, with higher velocities parallel to the local, NW-SE fabric of the geologic structure. Empirical Green`s function results for the 25 ton shots show increasing corner frequency with depth, consistent with predictions of the Mueller-Murphy source model.
Date: December 31, 1998
Creator: Pearson, D.C.; Phillips, W.S.; Glenn, L.A. & Denny, M.D.
Partner: UNT Libraries Government Documents Department

The Feasibility of Monitoring Continuous Wave Sources with Seismic Arrays

Description: This paper identifies and explores the technical requirements and issues associated with remotely monitoring continuous wave (CW) sources with seismic arrays. Potential approaches to this monitoring problem will be suggested and partially evaluated to expose the monitoring challenges which arise when realistic local geologies and cultural noise sources are considered. The selective directionality and the adaptive noise cancellation properties of arrays are required to observe weak signals while suppressing a colored background punctuated with an unknown distribution of point and sometimes distributive sources. The array is also required to characterize the emitters and propagation environment so as to properly focus on the CW sources of interest while suppressing the remaining emitters. The proper application of arrays requires an appreciation of the complexity of propagation in a non-homogeneous earth. The heterogeneity often limits the available spatial coherence and therefore the size of the army. This adversely impacts the array gain and the array's ability to carefully resolve various emitters. Arrays must also contend with multipath induced by the source and the heterogeneous earth. If the array is to focus on an emitter and realize an enhancement in the signal to noise ratio, methods must be sought to coherently add the desired signal components while suppressing interference which may be correlated with the desired signal. The impact of these and other issues on army design and processing are described and discussed.
Date: March 15, 1999
Creator: Claassen, J.P.; Elbring, G. & Ladd, M.
Partner: UNT Libraries Government Documents Department

Robust and intelligent bearing estimation

Description: As the monitoring thresholds of global and regional networks are lowered, bearing estimates become more important to the processes which associate (sparse) detections and which locate events. Current methods of estimating bearings from observations by 3-component stations and arrays lack both accuracy and precision. Methods are required which will develop all the precision inherently available in the arrival, determine the measurability of the arrival, provide better estimates of the bias induced by the medium, permit estimates at lower SNRs, and provide physical insight into the effects of the medium on the estimates. Initial efforts have focused on 3-component stations since the precision is poorest there. An intelligent estimation process for 3-component stations has been developed and explored. The method, called SEE for Search, Estimate, and Evaluation, adaptively exploits all the inherent information in the arrival at every step of the process to achieve optimal results. In particular, the approach uses a consistent and robust mathematical framework to define the optimal time-frequency windows on which to make estimates, to make the bearing estimates themselves, and to withdraw metrics helpful in choosing the best estimate(s) or admitting that the bearing is immeasurable. The approach is conceptually superior to current methods, particular those which rely on real values signals. The method has been evaluated to a considerable extent in a seismically active region and has demonstrated remarkable utility by providing not only the best estimates possible but also insight into the physical processes affecting the estimates. It has been shown, for example, that the best frequency at which to make an estimate seldom corresponds to the frequency having the best detection SNR and sometimes the best time interval is not at the onset of the signal. The method is capable of measuring bearing dispersion, thereby withdrawing the bearing bias as a function of ...
Date: July 1, 1998
Creator: Claassen, J.P.
Partner: UNT Libraries Government Documents Department

Naturally fractured tight gas reservoir detection optimization

Description: Exploration strategies are needed to identify subtle basement features critical to locating fractured regions in advance of drilling in tight gas reservoirs. The Piceance Basin served as a demonstration site for an analysis utilizing aeromagnetic surveys, remote sensing, Landsat Thematic Mapper, and Side Looking Airborne Radar imagery for the basin and surrounding areas. Spatially detailed aeromagnetic maps were used to to interpret zones of basement structure.
Date: May 1, 1995
Creator: Decker, D.
Partner: UNT Libraries Government Documents Department

Advanced array techniques for unattended ground sensor applications

Description: Sensor arrays offer opportunities to beam form, and time-frequency analyses offer additional insights to the wavefield data. Data collected while monitoring three different sources with unattended ground sensors in a 16-element, small-aperture (approximately 5 meters) geophone array are used as examples of model-based seismic signal processing on actual geophone array data. The three sources monitored were: (Source 01). A frequency-modulated chirp of an electromechanical shaker mounted on the floor of an underground bunker. Three 60-second time-windows corresponding to (a) 50 Hz to 55 Hz sweep, (b) 60 Hz to 70 Hz sweep, and (c) 80 Hz to 90 Hz sweep. (Source 02). A single transient impact of a hammer striking the floor of the bunker. Twenty seconds of data (with the transient event approximately mid-point in the time window.(Source 11)). The transient event of a diesel generator turning on, including a few seconds before the turn-on time and a few seconds after the generator reaches steady-state conditions. The high-frequency seismic array was positioned at the surface of the ground at a distance of 150 meters (North) of the underground bunker. Four Y-shaped subarrays (each with 2-meter apertures) in a Y-shaped pattern (with a 6-meter aperture) using a total of 16 3-component, high-frequency geophones were deployed. These 48 channels of seismic data were recorded at 6000 and 12000 samples per second on 16-bit data loggers. Representative examples of the data and analyses illustrate the results of this experiment.
Date: May 6, 1997
Creator: Followill, F.E.; Wolford, J.K. & Candy, J.V.
Partner: UNT Libraries Government Documents Department

Source and Path Effects on Regional Phases in China

Description: As part of the CTBT Research and Development regional characterization effort, we are assembling, organizing and analyzing geological, geophysical,and seismic data for inclusion in a knowledge base for China. We have collected seismic data from 11 Chinese Digital Seismic Network (CDSN) stations as well as IRIS stations AAK, TLY, ULN and NIL from adjoining regions. Using the published event locations and origin times, we identify Pn, Pg, Sn, and Lg phases,construct travel time curves, and estimate apparent velocities from broadband and short period seismograms. Following this, we collect amplitudes of regional seismic phases and associated noise levels using bandpassed waveforms. Studies of path specific propagation of the seismic phases have mapped blockages and have generated corrections useful in reducing scatter in magnitude estimates and in discriminant ratios. Such path corrections reduce RMS distance and mb- corrected Lg amplitude to as much as 60% of its original level (log{sub 10} domain). Path corrections are less effective with Pn data. We also study source scaling effects on these data which will allow us to refine path corrections further.
Date: December 31, 1997
Creator: Phillips, W.S., Randall, G.E., Hartse, H.E., Taylor, S.R., Patton, H.J.
Partner: UNT Libraries Government Documents Department

Automated Data Processing (ADP) research and development

Description: Monitoring a comprehensive test ban treaty (CTBT) will require screening tens of thousands of seismic events each year. Reliable automated data analysis will be essential in keeping up with the continuous stream of events that a global monitoring network will detect. We are developing automated event location and identification algorithms by looking at the gaps and weaknesses in conventional ADP systems and by taking advantage of modem computational paradigms. Our research focus is on three areas: developing robust algorithms for signal feature extraction, integrating the analysis of critical measurements, and exploiting joint estimation techniques such as using data from acoustic, hydroacoustic, and seismic sensors. We identify several important problems for research and development; e.g., event location with approximate velocity models and event identification in the presence of outliers. We are employing both linear and nonlinear methods and advanced signal transform techniques to solve these event monitoring problems. Our goal is to increase event-interpretation throughput by employing the power and efficiency of modem computational techniques, and to improve the reliability of automated analysis by reducing the rates of false alarms and missed detections.
Date: July 1, 1995
Creator: Dowla, F.U.; Kohlhepp, V.N. & Leach, R.R. Jr.
Partner: UNT Libraries Government Documents Department

Event location in the Middle East and North Africa

Description: The Lawrence Livermore National Laboratory (LLNL) CTBT R{ampersand}D program has made significant progress towards improving the ability of the IMS seismic network to locate small-magnitude events in the Middle East and North Africa (MIYNA). Given that high-grade ground truth (such as known explosions) has been difficult to obtain in these regions, we have placed a significant effort towards the development of a teleseismically constrained seismic database that provides event locations good to within 20m km. This data set is used to make an initial evaluation of the effectiveness of calibration on the proposed seismic IMS network in the MWNA. Utilizing a surrogate IMS regional network in the Middle East we find that when a seismic event lies within the footprint of the recording network the uncalibrated event locations are good to within about 25 km of the teleseismically constrained (TC) location. Using region-specific static station corrections further reduces this difference to about 20 km. To obtain further improvement in location accuracy we have used the modified kriging technique developed by SNL to interpolate new travel-time corrections. We compare this technique withe other robust linear interpolation techniques with the goal of enhancing the estimation of travel-time corrections. This is important to TC events which we find can have large uncorrelated uncertainties. Finally, we are making a large effort to incorporate LLNL analyst picks on primary and secondary phases and develop azimuth and slownsess estimates horn current IMS arrays to improve/supplement the NEIC picks.
Date: July 1, 1997
Creator: Schultz, C. A.; Myers, S. C. & Ruppert, S. D.
Partner: UNT Libraries Government Documents Department

Proceedings of the 2009 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

Description: These proceedings contain papers prepared for the Monitoring Research Review 2009: Ground -Based Nuclear Explosion Monitoring Technologies, held 21-23 September, 2009 in Tucson, Arizona,. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Test Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States’ capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 21, 2009
Creator: Wetovsky, Marv A; Aguilar-Chang, Julio; Anderson, Dale; Arrowsmith, Marie; Arrowsmith, Stephen; Baker, Diane et al.
Partner: UNT Libraries Government Documents Department

Savannah River Plant seismograph network

Description: The network consists of three field seismometer sites (SRPN, SRPW, SRPD) and one central recording station. The seismic activity at each field site is detected by a seismometer, which is a movable coil that induces a series of electric impulses when vibrated. These electrical impulses are amplified and sent over telephone lines to a central recording site, where the signals are again amplified and then recorded by a heated stylus on heat-sensitive paper. The signals from sites SRPN and SRPW are fed directly to telephone lines, but the signal for SRPD is first transmitted by radio to the D-area powerhouse and then fed into a telephone line for transmission to the recording station. The signals from seismometer site SRPN are recorded at two different gains (high and medium) to permit different resolutions for earthquakes of different magnitudes. Performance of the system is described.
Date: January 1, 1980
Creator: Krapp, C W
Partner: UNT Libraries Government Documents Department

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 structure of the Rio Grande Rift and the Jemez Mountains. (ACR)
Date: January 1, 1981
Creator: Cash, D.J.
Partner: UNT Libraries Government Documents Department

Seismic monitoring of a flow test in the Salton Sea Geothermal Field

Description: The purpose of this seismic monitoring project was to characterize in detail the micro-seismic activity related to the flow-injection test in the Salton Sea Geothermal Field. Our goal was to determine if any sources of seismic energy related to the test were observable at the surface, using both conventional seismic network techniques and relatively newer array techniques. These methods allowed us to detect and locate both impulsive microearthquakes and continuous sources of seismic energy. Our network, which was sensitive enough to be triggered by magnitude 0.0 or larger events, found no impulsive microearthquakes in the vicinity of the flow test in the 8 month period before the test and only one event during the flow test. We have observed some continuous seismic noise sources that may be attributed to the flow test. 4 refs., 4 figs.
Date: June 1, 1989
Creator: Jarpe, S.P.; Kasameyer, P.W. & Johnston, C.
Partner: UNT Libraries Government Documents Department

Variability of relative site response at Los Alamos, NM

Description: To estimate the range of seismic response at low strain of sites within Los Alamos National Laboratory, ground motion recordings were obtained at 13 sites from nuclear tests carried out in Nevada. The sites are distributed within a 10 X 10 km area. The ground motions recorded at each site were conceptually modelled as the result of source, path, and site contributions. Because almost all of the paths are in common, the variations seen for each source can be attributed to site response. The sites were monitored in various combinations with seven nuclear tests; each site recorded only a few of the tests. Because horizontal ground motion is more important for structural engineering and was larger than the vertical, we focused on horizontal site response. The range of relative site response seen is about a factor of 5 to 6 at 1.5 Hz. Topography has a strong effect on response, with sites in canyons being a factor of 3 to 4 lower than nearby sites on mesas. Increased depth to seismic basement beneath some stations also correlates with higher relative site response. Relative site response does not obviously correlate with variation of seismic velocities in the near surface (e.g. upper few meters). 5 refs., 4 figs.
Date: January 1, 1989
Creator: House, L. & Phillips, W.S. (Los Alamos National Lab., NM (USA))
Partner: UNT Libraries Government Documents Department

Proceedings of the symposium on the Long Valley Caldera: A pre-drilling data review

Description: This proceedings volume contains papers or abstracts of papers presented at a two-day symposium held at the Lawrence Berkeley Laboratory (LBL) on 17 and 18 March 1987. Speakers presented a large body of new scientific results and geologic-hydrogeoloic interpretations for the Long Valley caldera. The talks and the discussions that followed focused on concepts and models for the present-day magmatic-hydrothermal system. Speakers at the symposium also addressed the topic of where to site future scientific drill holes in the caldera. Deep scientific drilling projects such as those being contemplated by the DOE Division of Geothermal Technology (DGT), under the Magma Energy Program, and by the DOE Office of Energy Research, Division of Engineering and Geosciences (DEG), along with the USGS and NSE, under the Continental Scientific Drilling Program (CSDP), will be major and expensive national undertakings. DOE/DEG is sponsoring a program of relatively shallow coreholes in the caldera, and DOE/DGT is considering the initiation of a multiphase program to drill a deep hole for geophysical observations and sampling of the ''near magmatic'' environment as early as FY 1988, depending on the DOE budget. Separate abstracts have been prepared for the individual papers.
Date: September 1, 1987
Creator: Goldstein, N.E. (ed.)
Partner: UNT Libraries Government Documents Department

Subsurface disposal of liquid low-level radioactive wastes at Oak Ridge, Tennessee

Description: At Oak Ridge National Laboratory (ORNL) subsurface injection has been used to dispose of low-level liquid nuclear waste for the last two decades. The process consists of mixing liquid waste with cement and other additives to form a slurry that is injected under pressure through a cased well into a low-permeability shale at a depth of 300 m (1000 ft). The slurry spreads from the injection well along bedding plane fractures and forms solid grout sheets of up to 200 m (660 ft) in radius. Using this process, ORNL has disposed of over 1.5 x 10/sup 6/ Ci of activity; the principal nuclides are /sup 90/Sr and /sup 137/Cs. In 1982, a new injection facility was put into operation. Each injection, which lasts some two days, results in the emplacement of approximately 750,000 l (180,000 gal) of slurry. Disposal cost per liter is approximately $0.30, including capital costs of the facility. This subsurface disposal process is fundamentally different from other operations. Wastes are injected into a low-permeability aquitard, and the process is designed to isolate nuclides, preventing dispersion in groundwaters. The porosity into which wastes are injected is created by hydraulically fracturing the host formation along bedding planes. The site is in the structurally complex Valley and Ridge Province. The stratigraphy consists of lower Paleozoic rocks. Investigations are under way to determine the long-term hydrologic isolation of the injection zone and the geochemical impact of saline groundwater on nuclide mobility. Injections are monitored by gamma-ray logging of cased observation wells to determine grout sheet orientation after an injection. Recent monitoring work has involved the use of tiltmeters, surface uplift surveys, and seismic arrays. 26 refs., 7 figs.
Date: January 1, 1986
Creator: Stow, S.H. & Haase, C.S.
Partner: UNT Libraries Government Documents Department

Integrated modeling and field study of potential mechanisms forinduced seismicity at The Geysers Goethermal Field, California

Description: In this paper, we present progress made in a study aimed atincreasing the understanding of the relative contributions of differentmechanisms that may be causing the seismicity occurring at The Geysersgeothermal field, California. The approach we take is to integrate: (1)coupled reservoir geomechanical numerical modeling, (2) data fromrecently upgraded and expanded NCPA/Calpine/LBNL seismic arrays, and (3)tens of years of archival InSAR data from monthly satellite passes. Wehave conducted a coupled reservoir geomechanical analysis to studypotential mechanisms induced by steam production. Our simulation resultscorroborate co-locations of hypocenter field observations of inducedseismicity and their correlation with steam production as reported in theliterature. Seismic and InSAR data are being collected and processed foruse in constraining the coupled reservoir geomechanicalmodel.
Date: June 7, 2006
Creator: Rutqvist, Jonny; Majer, Ernie; Oldenburg, Curt; Peterson, John & Vasco, Don
Partner: UNT Libraries Government Documents Department

Louisiana Gulf Coast seismicity induced by geopressured-geothermal well development

Description: Continuous microseismic monitoring networks have been established around three US Department of Energy geopressured-geothermal design wells in southwestern Louisiana since summer 1980 to assess the effects well development may have on subsidence and growth fault activation. The results obtained from this monitoring have shown several unusual characteristics associated with Gulf Coast seismic activity. The observed activity is classified into two dominant types, one with identifiable body phases and the other with only surface wave signatures. The latter type comprises over 99% of the reported 1000+ microseismic event locations. The problem with the slow-moving surface-wave signature events is that rainfall and weather-associated frontal passages seem closely related to these periods of seismic activity at all three wells. After relatively short periods and low levels of flow testing at the Parcperdue and Sweet Lake prospects, seismic monitoring has shown little credible correlation to inferred growth fault locations during periods of flow testing. Longer periods and higher volumes of flow testing at the Rockefeller Refuge prospect should provide a truer indication of induced seismicity attributable to geopressured-geothermal development. 4 refs., 5 figs.
Date: January 1, 1985
Creator: Stevenson, D.
Partner: UNT Libraries Government Documents Department