Kinetic model for the short-term dissolution of a rhyolitic glass
A. F. White, H.C. Claassen
1980, Chemical Geology (28) 91-109
Aqueous dissolution experiments with the vitric phase of a rhyolitic tuff were performed at 25??C and constant pH in the range 4.5-7.5. Results suggest interchange of aqueous hydrogen ions for cations situated both on the surface and within the glass. At time intervals from 24 to 900 hr., dissolution kinetics...
Tectonic state: its significance and characterization in the assessment of seismic effects associated with reservoir impounding
R. O. Castle, M. M. Clark, A. Grantz, J.C. Savage
1980, Engineering Geology (15) 53-99
Any analysis of seismicity associated with the filling of large reservoirs requires an evaluation of the natural tectonic state in order to determine whether impoundment is the basic source, a mechanically unrelated companion feature, or a triggering stimulus of the observed seismicity. Several arguments indicate that the associated seismicity is...
Ocean eddy structure by satellite radar altimetry required for iceberg towing
W. J. Campbell, R. E. Cheney, J. G. Marsh, N. M. Mognard
1980, Cold Regions Science and Technology (1) 211-221
Models for the towing of large tabular icebergs give towing speeds of 0.5 knots to 1.0 knots relative to the ambient near surface current. Recent oceanographic research indicates that the world oceans are not principally composed of large steady-state current systems, like the Gulf Stream, but that most of the...
Elastic moduli of rock glasses under pressure to 8 kilobars and geophysical implications
R. Meister, E.C. Robertson, R.W. Werke, R. Raspet
1980, Journal of Geophysical Research Solid Earth (85) 6461-6470
Shear and longitudinal velocities were measured by the ultrasonic phase comparison method as a function of pressure to 8 kbar on synthetic glasses of basalt, andesite, rhyolite, and quartz composition and on natural obsidian. Velocities of most of the glasses decrease anomalously with pressure, but increasingly more-normal behavior occurs with...
The age curves of sulfur and oxygen isotopes in marine sulfate and their mutual interpretation
George E. Claypool, William T. Holser, Isaac R. Kaplan, Hitoshi Sakai, Israel Zak
1980, Chemical Geology (28) 199-260
Three hundred new samples of marine evaporite sulfate, of world-wide distribution, were analyzed for δ34S, and 60 of these also for δ18O in the sulfate ion. Detailed δ34S age curves for Tertiary—Cretaceous, Permian—Pennsylvanian, Devonian, Cambrian and Proterozoic times document large variations in δ34S. A summary curve forδ18O also shows definite...
A model to forecast short-term snowmelt runoff using synoptic observations of streamflow, temperature, and precipitation
Wendell V. Tangborn
1980, Water Resources Research (16) 778-786
Snowmelt runoff is forecast with a statistical model that utilizes daily values of stream discharge, gaged precipitation, and maximum and minimum observations of air temperature. Synoptic observations of these variables are made at existing low- and medium-altitude weather stations, thus eliminating the difficulties and expense of new, high-altitude installations. Four...
The behavior of 14C and 13C in estuarine water: Effects of In situ CO2 production and atmospheric exchange
Elliott C. Spiker
1980, Radiocarbon (22) 647-654
The effects of nonconservative sources (inputs) and sinks (outputs) of carbon are indicated by the behavior of Δ14C and δ13C of the total dissolved inorganic carbon (ΣCO2) in San Francisco Bay and Chesapeake Bay. Isotopic distributions and model calculations indicate that in North San Francisco Bay the net CO2 flux to...
Computational methods for inverse problems in geophysics: Inversion of travel time observations
V. Pereyra, H.B. Keller, W.H.K. Lee
1980, Physics of the Earth and Planetary Interiors (21) 120-125
General ways of solving various inverse problems are studied for given travel time observations between sources and receivers. These problems are separated into three components: (a) the representation of the unknown quantities appearing in the model; (b) the nonlinear least-squares problem; (c) the direct, two-point ray-tracing problem used to compute...
Rate of mercury loss from contaminated estuarine sediments
Michael H. Bothner, R.A. Jahnke, M. L. Peterson, R. Carpenter
1980, Geochimica et Cosmochimica Acta (44) 273-285
The concentration of mercury in contaminated estuarine sediments of Bellingham Bay, Washington was found to decrease with a half-time of about 1.3 yr after the primary anthropogenic source of mercury was removed. In situ measurements of the mercury flux from sediments, in both dissolved and volatile forms, could not account...
Travel time variation on backcountry trails
J. W. van Wagtendonk, J.M. Benedict
1980, Journal of Leisure Research (12) 99-106
Numerous interrelated factors influence the travel times of hikers and riders on backcountry trails. This study sought to quantify those factors which were thought to be most important in affecting trail speeds. The travel times of 897 backpacking parties, 634 day hiking parties, and 111 riding parties were obtained from...
Earthquakes, January-February, 1980
W. J. Person
1980, Earthquake Information Bulletin (USGS) (12) 200-202
Two major earthquakes (magntidue 7.0-7.9) occurred during this reporting period. The first struck in the North Atlantic Ocean in the Azores Islands on News Year's Day, causing fatalities and damage. The second major quake was on February 24 in the sparsely populated Kuril Islands of the northwest Pacific. A magnitude...
Earthquakes, July-August, 1979
W. J. Person
1980, Earthquake Information Bulletin (USGS) (12) 36-39
There was one major (magnitude 7.0-7.9) earthquake during this reporting period. The quake occurred on August 26 in the Philippine Islands. Strong or damaging earthquakes, which struck many parts of the world, caused casualties and damage; deaths were reported in China and Kashmir, and damaging earthquakes occurred in Costa Rica,...
The Southern California uplift revisited
R. A. Kerr
1980, Earthquake Information Bulletin (USGS) (12) 98-103
The earthquake that struck Livermore, east of San Francisco, on January 24 was the second moderate earthquake to have occurred in the San Francisco Bay area in 5 months. It raised familiar questions. Does this mean that the "Big One" is coming? Is the theater of heightened concern now in...
Accuracy of an estuarine hydrodynamic model using smooth elements
Roy A. Walters, Ralph T. Cheng
1980, Water Resources Research (16) 187-195
A finite element model which uses triangular, isoparametric elements with quadratic basis functions for the two velocity components and linear basis functions for water surface elevation is used in the computation of shallow water wave motions. Specifically addressed are two common uncertainties in this class of two-dimensional hydrodynamic models: the...
Holocene Pacific–North American plate interaction in southern Alaska: Implications for the Yakataga seismic gap
J.C. Lahr, George Plafker
1980, Geology (8) 483-486
The St. Elias, Alaska, earthquake (magnitude 7.1 Ms) on February 28, 1979, occurred along the complex Pacific–North American plate boundary between Yakutat Bay and Prince William Sound, rupturing only a fraction of the seismic gap identified in that region. To aid in evaluating the...
Supplementary modification and introduction of code numbers to the low-latitude coccolith biostratigraphic zonation (Bukry, 1973; 1975)
H. Okada, D. Bukry
1980, Marine Micropaleontology (5) 321-325
No abstract available. ...
Minimum size limits for yellow perch (Perca flavescens) in western Lake Erie
Wilbur L. Hartman, Stephen J. Nepszy, Russell L. Scholl
1980, Technical Report 39
During the 1960's yellow perch (Perca flavescens) of Lake Erie supported a commercial fishery that produced an average annual catch of 23 million pounds, as well as a modest sport fishery. Since 1969, the resource has seriously deteriorated. Commercial landings amounted to only 6 million pounds in 1976, and included...
Morphology of Lonar Crater, India: Comparisons and implications
R.F. Fudali, D.J. Milton, K. Fredriksson, A. Dube
1980, The Moon and the Planets (23) 493-515
Lonar Crater is a young meteorite impact crater emplaced in Deccan basalt. Data from 5 drillholes, a gravity network, and field mapping are used to reconstruct its original dimensions, delineate the nature of the pre-impact target rocks, and interpret the emplacement mode of the ejecta. Our estimates of the pre-erosion...
The frontal method in hydrodynamics simulations
Roy A. Walters
1980, Computers and Fluids (8) 265-272
The frontal solution method has proven to be an effective means of solving the matrix equations resulting from the application of the finite element method to a variety of problems. In this study, several versions of the frontal method were compared in efficiency for several hydrodynamics problems. Three basic modifications...
Circular current loops, magnetic dipoles and spherical harmonic analysis.
L.R. Alldredge
1980, Journal of Geomagnetism & Geoelectricity (32) 357-364
Spherical harmonic analysis (SHA) is the most used method of describing the Earth's magnetic field, even though spherical harmonic coefficients (SHC) almost completely defy interpretation in terms of real sources. Some moderately successful efforts have been made to represent the field in terms of dipoles placed in the core in...
Toxicity of five forest insecticides to cutthroat trout and two species of aquatic invertebrates
D. F. Woodward, W.L. Mauck
1980, Bulletin of Environmental Contamination and Toxicology (25) 846-854
The Northern Rocky Mountain region has had scattered infestation of the western spruce budworm Christoneura occidentalis since the early 1900's (U.S. DEPARTMENT OF AGRICULTURE (USDA) 1976b). On the basis of aerial surveys in 1975, TUNNOCK et al. (1976), estimated that budworm defoliation occurred on 2,278,804 acres of six National Forests...
Circum-arctic plate accretion - Isolating part of a pacific plate to form the nucleus of the Arctic Basin
M. Churkin Jr., J.H. Trexler Jr.
1980, Earth and Planetary Science Letters (48) 356-362
A mosaic of large lithospheric plates rims the Arctic Ocean Basin, and foldbelts between these plates contain numerous allochthonous microplates. A new model for continental drift and microplate accretion proposes that prior to the late Mesozoic the Kula plate extended from...
Tertiary δ18O record and glacio-eustatic sea-level fluctuations
R.K. Matthews, R.Z. Poore
1980, Geology (8) 501-504
Previous interpretation of the Tertiary δ18O record of plaiiktic and benthic foraminifers has emphasized comparison to the modern ocean, assumed an ice-free world prior to middle Miocene time, and thereby calculated surprisingly cool temperatures for the tropical sea surface. We propose an alternative...
On the extraction of directional sea-wave spectra from synthetic- aperture radar-signal arrays without matched filtering.
R.L. Wildey
1980, Modern Geology (7) 147-159
An economical method of digitally extracting sea-wave spectra from synthetic-aperture radar-signal records, which can be performed routinely in real or near-real time with the reception of telemetry from Seasat satellites, would be of value to a variety of scientific disciplines. This paper explores techniques for such data extraction and concludes...
The role of volatiles and lithology in the impact cratering process.
Kieffer S. Werner, C.H. Simonds
1980, Reviews of Geophysics and Space Physics (18) 143-181
A survey of published descriptions of 32 of the largest, least eroded terrestrial impact structures reveals that the amount of melt at craters in crystalline rocks is approximately 2 orders of magnitude greater than at craters in sedimentary rocks. In this paper we present a model for the impact process;...
