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in subjects: "Craters"

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On Cratering: A Brief History, Analysis, and Theory of Cratering

Cratering is a subject that has been studied by many investigators for many years for many purposes. These purposes range from experimental studies of physical properties to large scale excavations using explosive charges of kiloton size. In the past ten years considerable effort has been devoted to cratering experiments for the purposes of determining the effects of cratering by nuclear explosions, with recent accent on Plowshare applications. From the large amount of data available for crater… more

Date: August 22, 1961

Creator: Nordyke, M. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Application of the implicit TENSOR code to studies of containment of undergound nuclear tests

The TENSOR code, a two-dimensional finite-difference code, has been used extensively for the solution of stress wave propagation problems in materials, particularly those associated with the containment of underground nuclear test. These problems are typically characterized by shock waves at early times and by nearly incompressible flow at later times. To address this type of problem more economically, an implicit Newmark time integration has been implemented. Implicit differencing requires the… more

Date: February 1, 1982

Creator: Burton, D.E.; Bryan, J.B.; Lettis, L.A. Jr. & Rambo, J.T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Rock equation of state: a constitutive computer model

A constitutive model for a rock equation of state was developed in HEMP and CEL-HEMP computer codes. The model includes the mechanical and thermal properties of soil, such as elasticity, pore closure, compaction, and vaporization. Three test problems were computed using the equation of state: ground motion following the LATIR event, impact vaporization of preheated plates, and surface motion produced from exploding a 3.7-kg(10-lb) charge at a depth of 6.5 m. Agreement between our computations f… more

Date: August 24, 1977

Creator: Kamegai, M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Evaluation of Anvil Points tests

This review report presents the analysis of some of the data, primarily the full-scale tests from the Anvil Points series. However, the crater data and particle size information include data from the Colony Mine tests conducted previous to Anvil Points. The status of the blast simulation codes used by Los Alamos are not discussed in this report except to mention that a three-dimensional version of the SHALE codes is now being used to calculate more complex test geometries. This paper reports so… more

Date: January 1, 1985

Creator: Dick, R.D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Single-charge craters excavated during subsurface high-explosive experiments at Big Black Test Site, Mississippi

Single-charge and row-charge subsurface cratering experiments were performed to learn how close-spacing enhances single-crater dimensions. Our first experimental phase established cratering curves for 60-lb charges of the chemical explosive. For the second phase, to be described in a subsequent report, the Row-cratering experiments were designed and executed. This data report contains excavated dimensions and auxiliary data for the single-charge cratering experiments. The dimensions for the row… more

Date: October 19, 1978

Creator: Woodruff, W. R. & Bryan, J. B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Cultural resources inventory and evaluation for Science City, conducted for expansion of the Maui Space Surveillance Site, Haleakala, Maui, Hawaii

As part of the environmental assessment process for the proposed modifications to the US Air Force Maui Space Surveillance Site, an archaeological survey was conducted of Science City, an observatory complex on a summit of Haleakala Mountain, Island of Maui, Hawaii. Inspection of the 3.1-ha facility revealed four archaeological sites, designated 50-11-2805 through 50-11-2808. All consist of one or more temporary, probably single-person shelters with leveled floors and walls of stacked stones. R… more

Date: July 1, 1991

Creator: Chatters, J. C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Blast induced subsidence in the craters of nuclear tests over coral

The craters from high-yield nuclear tests at the Pacific Proving Grounds are very broad and shallow in comparison with the bowl-shaped craters formed in continental rock at the Nevada Test Site and elsewhere. Attempts to account for the differences quantitatively have been generally unsatisfactory. We have for the first time successfully modeled the Koa Event, a representative coral-atoll test. On the basis of plausible assumptions about the geology and about the constitutive relations for cora… more

Date: February 1, 1985

Creator: Burton, D.E.; Swift, R.P.; Glenn, H.D. & Bryan, J.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Research on gas transport in chimneys: a progress report

The results of the AGRINI and TIERRA experiments have led us to study three general topics: collapse phenomenology, CO/sub 2/ content measurement, and gas transport in chimneys. Our results so far are fragmentary, but we have been able to come to some tentative conclusions: (1) a layer of strong material between depths of 24 and 32 m, and perhaps some relatively strong material deeper, may have caused the AGRINI crater shape. This layer was absent at the nearby LABAN and CROWDIE events. We were… more

Date: March 18, 1986

Creator: Hearst, J. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Two-Dimensional Computer Simulation of Hypervelocity Impact Cratering: Some Preliminary Results for Meteor Crater, Arizona

A computational approach used for subsurface explosion cratering was extended to hypervelocity impact cratering. Meteor (Barringer) Crater, Arizona, was selected for the first computer simulation because it is one of the most thoroughly studied craters. It is also an excellent example of a simple, bowl-shaped crater and is one of the youngest terrestrial impact craters. Initial conditions for this calculation included a meteorite impact velocity of 15 km/s, meteorite mass of 1.67 x 10/sup 8/ kg… more

Date: June 1978

Creator: Bryan, J. B.; Burton, D. E.; Cunningham, M. E. & Lettis, L. A., Jr.

Item Type: Article

Location: None

Partner: UNT Libraries Government Documents Department

open access

Evidence for a solar companion star

Periodicity seen in both the mass extinctions and large impact cratering on earth can be explained if one postulates that the sun has a companion star, orbiting in a moderately eccentric orbit with a major axis of 2.8 light-years. No other explanations that have been suggested are compatible with known facts of physics and astronomy. If the companion is a red dwarf star, the most common kind in the galaxy, then no previous astronomical observations would have found it. A search for red objects … more

Date: August 1, 1984

Creator: Muller, Richard A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Design and execution of the Rayleigh wave experimental program at Yucca Lake, Nevada

Design and field execution of seismic experiments are described that recorded the characteristics of seismic signals from single and multiple explosions conducted at the Nevada Test Site in Yucca Flat, Nevada. Most of the data were obtained from small-scale underground explosions (total yields ranged from a fraction of a pound to 100 lb of explosives) that were designed to permit characterization of seismic signals as a function of explosive-source configuration. Other data were from explosions… more

Date: June 22, 1978

Creator: Kusubov, A.S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Effects of structural setting and rock peroperties on amplitudes of surface motions in the vicinity of small explosive tests

A series of small-scale explosive experiments were conducted in a perlite mine near Socorro, New Mexico. These experiments were a joint effort between Los Alamos National Laboratory, New Mexico Institute Of Mining and Technology, Southern Methodist University, and Defense Nuclear Agency. The purpose of these tests was to measure the changes in the shock wave and seismic coupling as a function of depth of burial and structural setting. The size of the explosive charges ranged from 1 to 68 kg. Ov… more

Date: December 1, 1993

Creator: Edwards, C. L.; Pearson, D. C.; Baker, D. F. & Aimone-Martin, C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Airblast environments from buried HE charges

Laboratory experiments were conducted to measure the airblast environment generated by the detonation of buried HE charges. Spherical 0.5-g charges of Nitropenta were used as the HE source. Three ground materials were used: (1) a porous, crushable grout (YTONG, {rho} = 0.4 g/cm{sup 3}); (2) a water-saturated grout ({rho} {approx_equal} 0.7 g/Cm{sup 3}) to investigate the effects of density increase; and (3) a clay-loam material ({rho} {approx_equal} 1.8 g/cm{sup 3}) to simulate some of the prev… more

Date: January 1, 1993

Creator: Reichenbach, H.; Behrens, K. & Kuhl, A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Response of rocks to large stresses. [Model for predicting response of ductile and brittle rocks to impact loading]

To predict the dimensions and characteristics of impact- and explosion-induced craters, one must know the equation of state of the rocks in which the crater is formed. Recent experimental data shed light upon inelastic processes that influence the stress/strain behavior of rocks. We examine these data with a view to developing models that could be used in predicting cratering phenomena. New data is presented on the volume behavior of two dissimilar rocks subjected to tensile stresses.

Date: November 10, 1976

Creator: Schock, R. N.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Global seismic effects of basin-forming impacts

Models of the thermal evolution of the moon and the terrestrial planets suggest that basin-forming impacts occurred when the planets had partially molten interiors overlain by thickening lithospheres, comparable in thickness to the basin radii. The effects of large impacts on planetary surfaces were investigated using a Lagrangian computer program which treats shock wave propagation and includes the effects of material strength, elastic-plastic behavior and material failure. The computer code a… more

Date: January 1, 1977

Creator: Hughes, H. G.; App, F. N. & McGetchin, T. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Addendum to the Corrective Action Decision Document/Closure Report for Corrective Action Unit 372: Area 20 Cabriolet/Palanquin Unit Craters Nevada National Security Site, Nevada, Revision 0

This document constitutes an addendum to the Corrective Action Decision Document/Closure Report for Corrective Action Unit 372: Area 20 Cabriolet/Palanquin Unit Craters, Nevada Test Site, Nevada (Revision 0), April 2011.

Date: January 1, 2012

Creator: Sloop, Patrick Matthews and Christy

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Corrective Action Investigation Plan for Corrective Action Unit 371: Johnnie Boy Crater and Pin Stripe Nevada Test Site, Nevada, Revision 0

Corrective Action Unit (CAU) 371 is located in Areas 11 and 18 of the Nevada Test Site, which is approximately 65 miles northwest of Las Vegas, Nevada. Corrective Action Unit 371 is comprised of the two corrective action sites (CASs) listed below: • 11-23-05, Pin Stripe Contamination Area • 18-45-01, U-18j-2 Crater (Johnnie Boy) These sites are being investigated because existing information on the nature and extent of potential contamination is insufficient to evaluate and recommend corrective… more

Date: February 1, 2009

Creator: Matthews, Patrick

Item Type: Report

Partner: UNT Libraries Government Documents Department

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The Beaverhead impact structure, SW Montana and Idaho: Implications for the regional geology of the western U.S.

The Beaverhead impact structure in SW Montana and Idaho is an allochthonous fragment of a large impact structure ({approximately} 100 km diameter) that was transported some distance eastward during the Cretaceous Sevier orogeny. It is the first tectonic fragment of a large impact structure identified in the geologic record. The present evidence for impact consists of shatter cones, pseudotachylites, and planar deformation features in quartz. The age of the impact is not well constrained but is … more

Date: March 17, 1994

Creator: Fiske, P.S. & Hargaves, R.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Rock mechanics contributions from defense programs

An attempt is made at illustrating the many contributions to rock mechanics from US defense programs, over the past 30-plus years. Large advances have been achieved in the technology-base area covering instrumentation, material properties, physical modeling, constitutive relations and numerical simulations. In the applications field, much progress has been made in understanding and being able to predict rock mass behavior related to underground explosions, cratering, projectile penetration, and… more

Date: February 1, 1992

Creator: Heuze, F.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Craters produced on metals by single ion impacts.

Single ion impacts have been observed using in-situ transmission electron microscopy during irradiation. In addition to internal defects, single-ion impacts create surface craters as large as 12 nm on In, Ag, Pb and Au. Crater formation rates have been determined from video recordings with a time-resolution of 33 milliseconds. The cratering rate for Xe ions increases linearly with increasing target mass density above a threshold density of approximately 7 gm/cm{sup 3}. The cratering rate increa… more

Date: December 23, 1998

Creator: Birtcher, R. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department