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Comprehensive study of the seismotectonics of the Aleutian Arc. Annual progress report, March 1, 1973--February 28, 1974

Description: Basic research is carried out to derive a coherent theory for the tectonic structure and geological history of the Alaska-Aleutian island arc in the framework of recent advancements of plate tectonics. An important part of this study is the evaluation of the seismic risk particularly in the eastern Aleutian arc which forms a major section of the active boundary between the North American and Pacific plates. The main effort during the current research term was concentrated on installation of a sufficiently dense and modern seismic station network. Two independent, telemetered networks were installed. One covers the Shumagin Islands region, a section of the eastern Aleutian Arc which was identified from earlier research as a region of susaected high risk for a possible major earthquakes in the not too distant future. Another less concentrated and rather elongated network was installed jointly with the University of Alaska along a roughly 1000 km long section of the eastern Aleutian arc east of longitude 168 deg W including the Alaskan Peninsula. It monitors the regional seismic background activity. Seismic data from these two networks provide the basis for testing physical models which were recently developed in an effort to advance systematic methods for earthquake prediction. (auth)
Date: January 1, 1974
Creator: Jacob, K.H.
Partner: UNT Libraries Government Documents Department

Electromagnetic pulse source characteristics experiment on an underground nuclear event

Description: From EMP technical meeting; Kirtland AFB, New Mexico, USA (25 Sep 1973). Under sponsorship of the Advanced Research Projects Agency, the Lawrence Livermore Laboratory conducted an EMP experiment in conjunction with an underground nuclear event. The purpose of the overall study of which this experiment was a part was to document the characteristics of EMP signals generated by various underground nuclear events to provide checks for theoretical models under development. A major goal was to establish how a specific event configuration affects the signals generated. For this experiment, two separate EMP source mechanisms were considered: that due to an asymmetric gamma ray distribution resulting from shielding and configuration constraints in the vicinity of the device and that due to current induced on the line-of-sight pipe. The instrumentation was not ideally located to sort out the two mechanisms because of significant differences between the planned and as-fired configuration. Nevertheless, signals characteristic of the two mechanisms seem to be apparent in the data. An impulsive (10 MHz) component of the signal is probably a result of the asymmetric gamma distribution. A ringing component (1 MHz) has been attributed to currents on the line-of- sight pipe. (auth)
Date: October 22, 1973
Creator: Knapp, M.W. & Bailey, N.D.
Partner: UNT Libraries Government Documents Department

Simulation of turbulence in fireballs

Description: The ALE technique is applied to the calculation of a small yield, low altitude nuclear explosion. When artificial diffusion effects caused by numerical errors are minimized, the fireball rises too rapidly, reaching an altitude in excess of that which is observed. This suggests that turbulent diffusion and entrainmert may be important. Hence, a turbulence model has been added to later calculations of the fireball dynamics. Some of the more important features of the calculational technique and the turbulence model are discussed. Preliminary results for a set of turbulence parameters and a particular low altitude fireball are presented. (auth)
Date: November 1, 1973
Creator: Ruppel, H.M.; Gentry, R.A. & Daly, B.J.
Partner: UNT Libraries Government Documents Department

Theoretical simulations of the gas explosive simulation technique (GEST) experiments

Description: To calibrate the ability to predict the dynamic behavior of nuclear fireballs the balloon detonations conducted under DNA sponsorship in November of 1973 have been simulated. These well-instrumented shots provide excellent data to test the reliability of hydrodynamic models for the rise and expansion of very low yield explosions. The results of calculations and conclusions drawn concerning the applicability of such techniques to nuclear fireball simulations are presented. (auth)
Date: October 1, 1975
Creator: Ruppel, H.M. & Norton, J.L.
Partner: UNT Libraries Government Documents Department

Tactical nuclear studies: a more comprehensive approach

Description: A matrix scheme for evaluating complex tactical nuclear systems is proposed. Advantages resulting from consideration of system characteristics in peace and crisis as well as war include avoidance of scenario-dependent conclusions, ease of maintaining awareness of relationships between immediate concerns and the complex whole, and highlighting of areas or concerns that have been overlooked or neglected. (auth)
Date: December 18, 1975
Creator: Blumenthal, D.; Kooshian, C.; Reinhardt, G. & Staehle, G.
Partner: UNT Libraries Government Documents Department

Project Drum Inlet: explosive excavation in saturated sand

Description: Seasonal storms during February of 1971 completely closed the Drum Inlet navigation channel through the Outer Banks off the North Carolina coast. This channel is highly useful to commercial and sport fishing industries in the Carteret County vicinity of North Carolina, and is vital to maintenance of the ecological balance in the inland Core Sound waters. To reopen Drum Inlet, an alignment about 2.1 miles south of the original location was selected. A contract dredge excavated a channel from the inland Core Sound waterway to and part way through the Outer Banks. The final 385-ft-long section of sand separating the Core Sound from the Atlantic Ocean was excavated with large explosive charges, This report describes the explosive excavation of that portion of the channel. Twenty-two separate canisters, each containing 1 ton of aluminized ammonium-nitrate slurry blasting agent, were emplaced in two rows. All charges were detonated simultaneously at 1327 hours, 23 Decembcr 1971. The detonation successfully removed the sand barrier, forming a continuous channel over 80 ft in width. This channel subsequently washed out to a width of about 1000 ft and was used:is an access route to the Raleigh Bay fishing grounds. The Drum Inlet project demonstrated the practicality of explosive channel excavation in saturated sand under the special conditions encountered at this site. (auth)
Date: October 1, 1973
Creator: Snell, C. M. & Gillespie, R. H.
Partner: UNT Libraries Government Documents Department

Project Trinidad: explosive excavation of railroad cuts 2 and 3 by mounding and directed blasting. Final technical report

Description: The objectives, design, and results of two explosive excavation experiments performed as the final phase of Project Trinidad, a comprehensive series of tests to determine the cratering properties of interbedded sandstones and shales, are summarized. The experiments were performed in September 1971 by the U.S. Army Engineer Waterways Experiment Station Explosive Excavation Research Laboratory. These final experiments were designed to excavate through- cuts for relocation of the Colorado and Wyoming Railroad at the Trinidad Dam and Lake Project. The first of the two experiments tested a charge array designed to break up material within a 19,000-yd/sup 3/ cut to facilitate later removal of the material by mechanical means. The concept tested was mounding, a blasting technique in which charges are positioned with respect to the horizontal ground surface rather than a vertical bench face. The results from this experiment confirmed the applicability of empirical scaling methods to the design of an array of deeply buried charges. The second experiment was a directed blasting detonation that was designed to produce a 30.000-yd/sup 3/ throughcut by cratering. This experiment tested a charge array design that had been developed by a combination of empirical scaling and kinematical methods. (auth)
Date: January 1, 1973
Creator: Lattery, J. E.
Partner: UNT Libraries Government Documents Department

Strain seismometer data from the ALMENDRO event at NTS

Description: The ALMENDRO Event was conducted on Pahute Mesa at NTS, and was announced as an intermediate yield event (200 to 1000 kt). Strainmeter records were obtalned at three locations in Yucca Flat. One recording site was a triaxial station; the other two were two component stations. The station parameters and pertinent data relating to ALMENDRO are summarized in tabular form. (TFD)
Date: November 1, 1973
Creator: Olsen, C. W.
Partner: UNT Libraries Government Documents Department