Variation of depth to the brittle-ductile transition due to cooling of a midcrustal intrusion
M. E. Gettings
1988, Geophysical Research Letters (15) 213-216
The depth to the brittle-ductile transition in the crust is often defined by the intersection of a shear resistance relation in the brittle upper crust that increases linearly with depth and a power law relation for ductile flow in the lower crust that depends strongly on...
Waveform modelling using locked-mode synthetic and differential seismograms: application to determination of the structure of Mexico
J.S. Gomberg, T. Guy Masters
1988, Geophysical Journal International (94) 193-218
We have developed algorithms for modelling seismic waveforms to constrain regional Earth structure. The seismogram is represented as a sum of locked-mode travelling waves in a layered medium. This representation is convenient as it allows us to model structures with slowly varying heterogeneity and to construct differential seismograms. Describes the...
Predation, herbivory and kelp evolution
J. A. Estes, P.D. Steinberg
1988, Paleobiology (14) 19-36
We propose that the kelps (Laminariales) radiated in the North Pacific following the onset of late Cenozoic polar cooling. The evidence is that (1) extant kelps occur exclusively in cold-water habitats; (2) all but one of 27 kelp genera occur in the North Pacific, 19 of these exclusively; and (3)...
Motor-operated valve for fish culturists
J. T. Fuss
1988, Progressive Fish-Culturist (50) 121-124
Many fish culture systems require motoroperated valves to regulate water flow. The expense of commercial units can be prohibitive but, by using inexpensive components and a little assembly time, a manual valve can be motorized for a fraction of the cost....
Fixed-wing airplane versus helicopter surveys of manatees (Trichechus manatus)
Galen B. Rathbun
1988, Marine Mammal Science (4) 71-75
The abundance of manatees, as with most marine mammals, is difficult to determine because they are visible for only short periods of time while at the surface of the water (Eberhardt et al. 1979, Powell et al. 1981). Aerial surveys are generally considered to be the most accurate method of...
Spatial variation of crustal coda Q in California
W.S. Philips, W.H.K. Lee, J.T. Newberry
1988, Pure and Applied Geophysics PAGEOPH (128) 251-260
Coda wave data from California microearthquakes were studied in order to delineate regional fluctuations of apparent crustal attenuation in the band 1.5 to 24 Hz. Apparent attenuation was estimated using a single back scattering model of coda waves. The coda wave data were restricted to ???30 s following the origin...
Thermal regime of the State 2-14 well, Salton Sea Scientific Drilling Project
J.H. Sass, S. S. Priest, L.E. Duda, C.C. Carson, J. D. Hendricks, L.C. Robison
1988, Journal of Geophysical Research Solid Earth (93) 12995-13004
Temperature logs were made repeatedly during breaks in drilling and both during and after flow tests in the Salton Sea Scientific Drilling Project well (State 2–14). The purpose of these logs was to assist in identifying zones of fluid loss or grain and to characterize reservoir temperatures. At the conclusion...
FUTURE APPLICATIONS OF EXPERT SYSTEMS FOR THE EVALUATION OF ENERGY RESOURCES.
Betty M. Miller
1988, JPT, Journal of Petroleum Technology (40) 348-352
The loss of professional experience and expertise in the domain of the earth sciences may prove to be one of the most serious outcomes of the boom-and-bust cyclic nature of the volatile energy and mining industries. Promising new applications of powerful computer systems, known as 'expert systems' or 'knowledge-based systems',...
Concurrent mobile on-site and in situ striped bass contaminant and water quality studies in the Choptank River and upper Chesapeake Bay
L. W. Hall Jr., S. J. Bushong, M.C. Ziegenfuss, W. S. Hall, R. L. Herman
1988, Environmental Toxicology and Chemistry (7) 815-830
In situ and mobile on-site striped bass prolarval and yearling survival studies were conducted in the Choptank River and in the Chesapeake and Delaware (C & D) Canal area of the Upper Chesapeake Bay. Extensive chemical analyses of both organic and inorganic contaminants in the habitat water were performed and water...
The geometric signature: Quantifying landslide-terrain types from digital elevation models
R.J. Pike
1988, Mathematical Geology (20) 491-511
Topography of various types and scales can be fingerprinted by computer analysis of altitude matrices (digital elevation models, or DEMs). The critical analytic tool is the geometric signature, a set of measures that describes topographic form well enough to distinguish among geomorphically disparate landscapes. Different surficial processes create topography with...
The plumbotectonic model for Pb isotopic systematics among major terrestrial reservoirs: A case for bi-directional transport
R. E. Zartman, S.M. Haines
1988, Geochimica et Cosmochimica Acta (52) 1327-1339
Version IV of plumbotectonics expands and refines the original model of Doe and Zartman (1979) and Zartman and Doe (1981) for explaining Pb (Sr, and Nd) isotopic systematics among major terrestrial reservoirs. A case for bi-directional transport among reservoirs is based on the observed isotopic compositions for different tectonic settings, and finds a rationale...
Rare earth elements in the phosphatic-enriched sediment of the Peru shelf
D.Z. Piper, P. A. Baedecker, J.G. Crock, W. C. Burnett, B.J. Loebner
1988, Marine Geology (80) 269-285
Apatite-enriched materials from the Peru shelf have been analyzed for their major oxide and rare earth element (REE) concentrations. The samples consist of (1) the fine fraction of sediment, mostly clay material, (2) phosphatic pellets and fish debris, which are dispersed throughout the fine-grained sediment, (3) tabular-shaped phosphatic crusts, which...
Geochemistry of water at Cajon Pass, California: Preliminary results
Y.K. Kharaka, G. Ambats, William C. Evans, A. F. White
1988, Geophysical Research Letters (15) 1037-1040
Samples of water and associated gases were collected from the Cajon Pass well using downhole samplers, and from the pipe stands at the completion of drill stem tests. The fluids were recovered from fracture systems in granitic rocks from two uncased test intervals located at 1,829...
Fractional-step method for two-dimensional estuarine transport
Jerad D. Bales, Edward R. Holley
1988, Conference Paper
The fractional-step method was used in this study to split the longitudinal advective transport term from the other terms in the two-dimensional, laterally-averaged equation for estuarine mass transport. The method of characteristics with spline interpolations was used to approximate the longitudinal advective transport. A general discussion of the fractional-step method,...
Preliminary evaluation of the ground-water resources of Bainbridge Island, Kitsap County, Washington, with a section on geohydrologic units
N. P. Dion, T. D. Olsen, K. L. Payne, M. A. Jones
1988, Water-Resources Investigations Report 87-4237
No abstract available....
Fish culture in the United States
N. C. Parker
C.J. Shephard, N.R. Bromage, editor(s)
1988, Book chapter, Intensive Fish Farming
No abstract available at this time...
Feeding ecology of canvasbacks staging on Pool 7 of the Upper Mississippi River
C. E. Korschgen, L. S. George, W. L. Green
M.W. Weller, editor(s)
1988, Book chapter, Waterfowl in winter
Foods consumed by canvasback ducks (Aythya valisineria), food availability, and energetic relationships were studied on Navigation Pool 7 of the upper Mississippi River in 1978, 1979, and 1980. Canvasbacks fed primarily upon winter buds of American wildcelery (Vallisneria americana) and tubers of stiff arrowhead (Sagittaria rigida). In 1980, waterfowl consumed...
Polar Bear
S.D. Amstrup, DeMaster
J.W. Lentfer, editor(s)
1988, Report, Selected marine mammals of Alaska: Species accounts with research and management recommendations, U. S. Marine Mammal Commission, Washington, D. C
Polar bears are long-lived, late-maturing carnivores that have relatively low rates of reproduction and natural mortality. Their populations are susceptible to disturbance from human activities, such as the exploration and development of mineral resources or hunting. Polar bear populations have been an important renewable resource available to coastal communities throughout...
Use of muscovy duck embryo fibroblasts for the isolation of viruses from wild birds
D. E. Docherty, Paul G. Slota
1988, Journal of Tissue Culture Methods (11) 165-170
Techniques are described for the preparation, cryopreservation, and inoculation of Muscovy duck embryo cell cultures. The procedure yields a susceptible reproducible cell culture system for the isolation and cultivation of viruses from wild birds....
Geologic time
William L. Newman
1988, Report
The information content of high-frequency seismograms and the near-surface geologic structure of "hard rock" recording sites
E. Cranswick
1988, Pure and Applied Geophysics PAGEOPH (128) 333-363
Due to hardware developments in the last decade, the high-frequency end of the frequency band of seismic waves analyzed for source mechanisms has been extended into the audio-frequency range (>20 Hz). In principle, the short wavelengths corresponding to these frequencies can provide information about the details of seismic sources, but...
Uranium-series age estimates and paleoclimatic significance of Pleistocene tufas from the Lahontan basin, California and Nevada
Y. Lao, L. Benson
1988, Quaternary Research (30) 165-176
An extended chronology of Lahontan basin lake levels based on uranium-series age estimates correlates with the global ice-volume record. Lake highstands occur at or shortly after times of maximum ice-sheet size. Moderate size lakes occur when the global ice volume is about 80% of its maximum. The data indicate that...
Effects of kelp forest removal on associated fish assemblages in central California
James L. Bodkin
1988, Journal of Experimental Marine Biology and Ecology (117) 227-238
Visual surveys along subtidal belt transects were used to compare fish assemblages on an experimental and a control site before and after the removal of a canopy-forming kelp forest. The giant kelp Macrocystis pyrifera (L.) C.A. Agardh was removed at the holdfast from ≈ 1 ha of high relief structurally complex rock...
Hydrologic Unit Map – 1988, states of Massachusetts, Rhode Island and Connecticut
Water Resources Division, U.S. Geological Survey
1988, Hydrologic Unit 21
No abstract available....
Fluid inclusions in vadose cement with consistent vapor to liquid ratios, Pleistocene Miami Limestone, southeastern Florida
C.E. Barker, R. B. Halley
1988, Geochimica et Cosmochimica Acta (52) 1019-1025
Vadose cements in the Late Pleistocene Miami Limestone contain regions with two-phase aqueous fluid inclusions that have consistent vapor to liquid (V-L) ratios. When heated, these seemingly primary inclusions homogenize to a liquid phase in a range between 75°C and 130°C (mean = 100°C) and have final melting temperatures between...
