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in subjects: "Volcanism"

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State-of-the-art for evaluating the potential impact of tectonism and volcanism on a radioactive waste repository

Most estimates of the time required for safe isolation of radioactive wastes from the biosphere range from 100,000 to 1,000,000 years. For such long time spans, it is necessary to assess the potential effects of geologic processes such as volcanism and tectonic activity on the integrity of geologic repositories. Predictions of geologic phenomena can be based on probabilistic models, which assume a random distribution of events. The necessary historic and geologic records are rarely available to… more

Date: July 16, 1980

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Seismological investigation of crack formation in hydraulic rock fracturing experiments and in natural geothermal environments. Progress report, September 1, 1979-August 31, 1980

Progress is reported in the following research areas: a synthesis of seismic experiments at the Fenton Hill Hot-Dry-Rock System; attenuation of high-frequency shear waves in the lithosphere; a new kinematic source model for deep volcanic tremors; ground motion in the near-field of a fluid-driven crack and its interpretation in the study of shallow volcanic tremor; low-velocity bodies under geothermal areas; and operation of event recorders in Mt. St. Helens and Newberry Peak with preliminary re… more

Date: September 1, 1980

Creator: Aki, K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Geology and geothermics of the Island of Milos (Greece)

Geothermal research which has been conducted on the island of Milos is reviewed and the island's geology is discussed in terms of the geodynamics of the eastern Mediterranean. The rock formations which outcrop at Milos are described in detail, including the crystalline basement, Neogene transgressive conglomerates and limestones, and the Quaternary volcanics and volcano-sedimentary series. The recent disjunctive tectonics and volcano-tectonics affecting Milos and the neighboring islands are rev… more

Date: January 1, 1976

Creator: Fytikas, M. & Marinelli, G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Variations in volatiles in magma bodies based on studies of melt inclusions

Knowledge of volatile concentrations in magmas are important in the prediction of explosive volcanism, and contribute to the understanding of the carbon dioxide budget of the atmosphere. Some important variables that are controlled by volatiles are: crystallization temperature of phases, composition of liquids minimum, and viscosity. Volatiles are also catalysts for reactions.

Date: June 15, 1989

Creator: Vogel, T. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Geologic evolution of the Jemez Mountains and their potential for future volcanic activity

Geophysical and geochemical data and the geologic history of the Rio Grande rift and the vicinity of the Jemez Mountains are summarized to determine the probability of future volcanic activity in the Los Alamos, New Mexico area. The apparent cyclic nature of volcanism in the Jemez Mountains may be related to intermittent thermal inputs into the volcanic system beneath the region. The Jemez lineament, an alignment of late Cenozoic volcanic centers that crosses the rift near Los Alamos, has playe… more

Date: January 1, 1982

Creator: Burton, B. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Chemistry of thermal waters and mineralogy of the new deposits at Mount St. Helens: a preliminary report

After May 18, 1980 eruption of Mount St. Helens, Washington, interactions between the hot deposits and shallow ground water produced ephemeral phreatic eruptions and thermal ponds and streams. In early June water and sediment samples were collected from about 20 sites in the devastated zone to study the initial alteration of the new deposits, and the effects of the eruption on water chemistry. The levels of certain trace elements in thermal waters, and whether these mineralized waters were reac… more

Date: December 1, 1980

Creator: Dethier, D.P.; Frank, D. & Peavear, D.R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Geothermal energy: Geology, exploration, and developments. Part I

Geology, exploration, and initial developments of significant geothermal areas of the world are summarized in this report which is divided into two parts. Part 1 is a review of the geological and explorational aspects of geothermal energy development; areas of potential development in the Western United States are also discussed. The most favorable geological environment for exploration and development of geothermal steam is characterized by recent normal faulting, volcanism, and high heat flow… more

Date: November 1971

Creator: Grose, L. T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Uranium potential of southwestern New Mexico (southern Hidalgo County), including observations on crystallization history of lavas and ash tuffs and the release of uranium from them. Final report

Geological environments present in southwestern New Mexico include thick sequences of sedimentary rock including limestone, conglomerates, sandstone, and shale: igneous intrusions with associated metal deposits; caldera centers, margins, and outflow facies; and basins with marginal faults and thick late Cenozoic sedimentary fillings. Predominant rock types are Paleozoic carbonates, Mesozoic terrigeneous rocks and carbonates, and Cenozoic volcanic rocks and basin-filling terrigeneous rocks. Cons… more

Date: August 1, 1980

Creator: Walton, A.W.; Salter, T.L. & Zetterlund, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Disruptive event analysis: volcanism and igneous intrusion

An evaluation is made of the disruptive effects of volcanic activity with respect to long term isolation of radioactive waste through deep geologic storage. Three major questions are considered. First, what is the range of disruption effects of a radioactive waste repository by volcanic activity. Second, is it possible, by selective siting of a repository, to reduce the risk of disruption by future volcanic activity. And third, can the probability of repository disruption by volcanic activity b… more

Date: August 1, 1980

Creator: Crowe, B.M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Summary of potassium/argon age dating, 1979

During FY-79 the K/Ar dating laboratory at the Department of Geology and Geophysics of the University of Utah became operational. During the past calendar year forty-seven dates have been produced from areas predominantly in Utah. Dating has also been done on areas in Nevada and Montana through the State-Coupled program and Case Studies Support program. Areas in wich activity was concentrated include: Cove Creek Domes/Twin Peaks Area, SW Utah. Here volcanic activity spanned the time from 2.74 t… more

Date: February 1, 1980

Creator: Evans, S.H. Jr.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Results from shallow research drilling at Inyo Domes, Long Valley Caldera, California and Salton Sea geothermal field, Salton Trough, California

This report reviews the results from two shallow drilling programs recently completed as part of the United States Department of Energy Continental Scientific Drilling Program. The purpose is to provide a broad overview of the objectives and results of the projects, and to analyze these results in the context of the promise and potential of research drilling in crustal thermal regimes. The Inyo Domes drilling project has involved drilling 4 shallow research holes into the 600-year-old Inyo Dome… more

Date: September 1, 1987

Creator: Younker, L.W.; Eichelberger, J.C.; Kasameyer, P.W.; Newmark, R.L. & Vogel, T.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Caldera processes and magma-hydrothermal systems continental scientific drilling program: thermal regimes, Valles caldera research, scientific and management plan

Long-range core-drilling operations and initial scientific investigations are described for four sites in the Valles caldera, New Mexico. The plan concentrates on the period 1986 to 1993 and has six primary objectives: (1) study the origin, evolution, physical/chemical dynamics of the vapor-dominated portion of the Valles geothermal system; (2) investigate the characteristics of caldera fill and mechanisms of caldera collapse and resurgence; (3) determine the physical/chemical conditions in the… more

Date: May 1, 1986

Creator: Goff, F. & Nielson, D.L. (eds.)

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Workshop on Potentially Disruptive Phenomena for Nuclear Waste Repositories, July 27-28, 1977

The workshop on Potentially Disruptive Phenomena for Nuclear Waste Repositories brought together experts in the geosciences to identify and evaluate potentially disruptive events and processes and to contribute ideas on how to extrapolate data from the past into the next one million years. The analysis is to be used to model a repository in geologic media for long-term safety assessments of nuclear waste storage. The workshop included invited presentations on the following items: an overview of… more

Date: January 1, 1977

Creator: Jacobson, J. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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(Investigation of subcooled hydrothermal boiling in ground water flow channels as a source of harmonic tremors)

As a first step toward assessing the ability of hydrothermal boiling to explain geothermal ground noise and volcanic tremor observations, we are investigating the acoustic power spectrum of boiling (the source'' spectrum in the above model). We simulate boiling in the lab by injecting high pressure steam from a boiler into a pressure vessel filled with water. The water pressure fluctuations that result from the repeated formation and collapse of steam bubbles at the steam inlet vents are record… more

Date: January 1, 1989

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Near-surface heat flow in Saline Valley, California

With the exception of values from one borehole drilled at Palm Spring and three boreholes drilled around Saline Valley dry lake, eight new heatflow values in Saline Valley, California, are within or somewhat below the range one would expect for this region of the Basin and Range heat-flow province. The lack of recent volcanism in the area and the apparently normal Basin and Range heat flow suggest that geothermal systems within the valley are stable stationary phases supported by high regional … more

Date: January 1, 1979

Creator: Mase, C. W.; Galanis, S. P., Jr. & Munroe, R. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Use of a United States mid-Pacific Island territory for a Pacific Island Repository System (PIRS): Extended summary

The concept of using a mid-ocean island for a geologic high-level waste repository was investigated. The technical advantages include geographical isolation and near-infinite ocean dilution as a backup to repository geological waste isolation. The institutional advantages are reduced siting problems and the potential of creating an international waste repository. Establishment of international waste repository would allow cost sharing, aid US nonproliferation goals, and assure proper disposal o… more

Date: August 1, 1987

Creator: Forsberg, Charles W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Computer simulations of explosive volcanic eruptions

We have adapted computer codes that provide such solutions to study explosive volcanic phenomena. These fully nonlinear conservation equations are cast in two-dimensional cylindrical coordinates, which with closure equations comprise 16 equations with 16 unknown variables. Solutions for several hundred seconds of simulated eruption time require two to three hours of a Cray-1 computer time. Over 100 simulations have been run to simulate the physics of highly unsteady blasts, sustained and steady… more

Date: January 1, 1989

Creator: Wohletz, K.H. & Valentine, G.A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Workshop on recent research in the Valles caldera

Over the last 5 years, there has been increased interest in the geology of the Jemez Mountains volcanic field, New Mexico. Of special interest is the Toledo-Valles caldera complex, which is targeted for research coring as part of the Continental Scientific Drilling Program. The general topics covered in this workshop were (1) hydrothermal systems and rock-water interactions, (2) volcanology and structural framework of the Jemez volcanic field, (3) determining the presence or absence of melt bel… more

Date: February 1, 1985

Creator: Heiken, G. (comp.)

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Volcanic ash: What it is and how it forms

There are four basic eruption processes that produce volcanic ash: (1) decompression of rising magma, gas bubble growth, and fragmentation of the foamy magma in the volcanic vent (magmatic), (2) explosive mixing of magma with ground or surface water (hydrovolcanic), (3) fragmentation of country rock during rapid expansion of steam and/or hot water (phreatic), and (4) breakup of lava fragments during rapid transport from the vent. Variations in eruption style and the characteristics of volcanic … more

Date: September 13, 1991

Creator: Heiken, G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Search for Shallow Magma Accumulations at Augustine Volcano

A search was made for shallow magma accumulations beneath Augustine Volcano using primarily three geophysical techniques: (1) temperature and heat flow measurements, (2) active and passive seismic refraction, and (3) three-dimensional modeling of aeromagnetic data. With these studies it was hoped to gain insight into the interval structure of Augustine Volcano, to delineate, if possible, the size and shape of near surface magma bodies and to assess the potential of the volcano as a natural labo… more

Date: May 1, 1979

Creator: Kienle, J.; Lalla, D. J.; Pearson, C. F. & Barrett, S. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Seismological investigation of crack formation in hydraulic rock-fracturing experiments and in natural geothermal environments. Progress report, September 1, 1982-August 31, 1983

Progress is reported on the following: interpretation of seismic data from the recent activities in Long Valley, California; theoretical study on a source model for the long-period events and volcanic tremor observed at Mount St. Helens; calculation of synthetic seismograms for the tremor source model; analysis of the Easter Island tremor records; testing and application of the Gaussian beam synthetic method to observations at Mount St. Helens; and field testing and development of a high-temper… more

Date: September 1, 1983

Creator: Aki, K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Geology and alteration of the Baltazor Hot Springs and Painted Hills Thermal Areas, Humboldt County, Nevada

The Baltazor Hot Springs KGRA and nearby Painted Hills thermal area are situated in Humboldt County, northwestern Nevada along the northwestern margin of the Basin and Range province. The oldest rocks exposed in the Baltazor area are eugeosynclinal metasedimentary and subordinate metavolcanic rocks of Permian to Triassic age intruded by Cretaceous diorite and quartz diorite. These are overlain by a thick volcanic and volcaniclastic sequence of Miocene through Pliocene age. Pre-Tertiary rocks ar… more

Date: December 1, 1979

Creator: Hulen, J. B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Balance of the tropospheric ozone and its relation to stratospheric intrusions indicated by cosmogenic radionuclides. Technical progress report, November 1, 1980-June 30, 1981

The balance of the tropospheric ozone is studied with regard to sources and sinks. The influx of stratospheric ozone through stratospheric intrusions and photochemical production under pure air conditions is discussed. The 4-year measuring series (1977-1980) of the ozone concentration measured at 3 different levels are evaluated, the influence of meteorological parameters is examined. The time variation of the ozone layer between 1000 and 3000 m ASL is investigated as a function of different oz… more

Date: June 1, 1981

Creator: Reiter, R.; Kanter, H. J.; Sladkovic, R.; Jaeger, H. & Munzert, K. H.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Geothermal power plants of Iceland: a technical survey of existing and planned installations

The technical features of the geothermal electric power plants of Iceland are described. Some description is given of the geology of the geothermal regions, and recent volcanic eruptions are discussed relative to their impact on the geothermal plant sites. The 3 MW, single-flash plant at Namafjall, the 60 MW, double-flash plant at Krafla, and the 1 MW unit at Grindavik are included. Information is given on well arrangements, casing programs, energy conversion systems, capital investments, and o… more

Date: November 1, 1978

Creator: DiPippo, R.

Item Type: Report

Partner: UNT Libraries Government Documents Department