Determinants of breeding distributions of ducks
Douglas H. Johnson, J.W. Grier
1988, Wildlife Monographs (100)
The settling of breeding habitat by migratory waterfowl is a topic of both theoretical and practical interest. We use the results of surveys conducted annually during 1955-81 in major breeding areas to examine the factors that affect the distributions of 10 common North American duck species. Three patterns of settling...
Accumulation and bioconcentration of polycyclic aromatic hydrocarbons in a nearshore estuarine environment near a Pensacola (Florida) creosote contamination site
J. F. Elder, P.V. Dresler
1988, Environmental Pollution (49) 117-132
Long-term accumulation of creosote wastes at a wood-preserving facility near Pensacola, Florida, has produced high levels of organic contamination of groundwaters near Pensacola Bay. Impacts of this contamination on the nearshore environment of the bay were examined by analysis of water, sediment and tissues of two mollusc species. One of...
A climatic-limnologic model of diatom succession for paleolimnological interpretation of varved sediments at Elk Lake, Minnesota
Bradbury J. Platt
1988, Journal of Paleolimnology (1) 115-131
Sediment traps placed in the profundal region of Elk Lake, north central Minnesota during the 1979 spring and 1983-84 fall and spring seasons monitored seasonal diatom production for two climatically distinctive periods. The spring of 1979 was one of the coldest and wettest on record. Ice out at Elk Lake...
Coastal erosion: Processes, timing and magnitudes at the bluff toe
C.H. Carter, D.E. Guy Jr.
1988, Marine Geology (84) 1-17
Five Lake Erie bluffs (one interlaminated clay and silt, three clay-rich diamicts and one shale) were surveyed at about 2-week intervals and after wind storms for up to 5 years. Erosion of the bluff toes along this low-energy coast occurred during...
Elastic-wave propagation and site amplification in the Salt Lake Valley, Utah, from simulated normal faulting earthquakes
H.M. Benz, R. B. Smith
1988, Bulletin of the Seismological Society of America (78) 1851-1874
The two-dimensional seismic response of the Salt Lake valley to near- and far-field earthquakes has been investigated from simulations of vertically incident plane waves and from normal-faulting earthquakes generated on the basin-bounding Wasatch fault. The response to normal faulting earthquakes was simulated using a two-dimensional finite-element method and the plane-wave...
Evidence for a new geomagnetic reversal from lava flows in Idaho: Discussion of short polarity reversals in the Brunhes and late Matuyama polarity chrons
D.E. Champion, M. A. Lanphere, M. A. Kuntz
1988, Journal of Geophysical Research Solid Earth (93) 11667-11680
K-Ar ages and paleomagnetic data for basalt samples from a new core hole (site E) at the Idaho National Engineering Laboratory (INEL) indicate that the age of the reversed polarity event recorded in Snake River Plain lavas is older than 465±50 ka (1000 years before present) reported previously by Champion...
High-resolution 40Ar 39Ar chronology of Oligocene volcanic rocks, San Juan Mountains, Colorado
M. A. Lanphere
1988, Geochimica et Cosmochimica Acta (52) 1425-1434
The central San Juan caldera complex consists of seven calderas from which eight major ash-flow tuffs were erupted during a period of intense volcanic activity that lasted for approximately 2 m.y. about 26–28 Ma. The analytical precision of conventional K-Ar dating in this time interval is not sufficient to unambiguously...
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...
The global distribution, abundance, and stability of SO2 on Io
A. S. McEwen, T. V. Johnson, D. L. Matson, L.A. Soderblom
1988, Icarus (75) 450-478
Sulfur dioxide distribution and abundances, bolometric hemispheric albedos, and passive surface temperatures on Io are modeled and mapped globally from Voyager multispectral mosaics, Earth-based spectra, and photometric descriptions. Photometric models indicate global average values for regolith porosity of 75-95% and macroscopic roughness with a mean slope angle of ~30??. Abundances...
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...
A statistical method for estimating rates of soil development and ages of geologic deposits: A design for soil-chronosequence studies
P. Switzer, J.W. Harden, R. K. Mark
1988, Mathematical Geology (20) 49-61
A statistical method for estimating rates of soil development in a given region based on calibration from a series of dated soils is used to estimate ages of soils in the same region that are not dated directly. The method is designed specifically to account for sampling procedures and uncertainties...
Using exogenous variables in testing for monotonic trends in hydrologic time series
William M. Alley
1988, Water Resources Research (24) 1955-1961
One approach that has been used in performing a nonparametric test for monotonic trend in a hydrologic time series consists of a two-stage analysis. First, a regression equation is estimated for the variable being tested as a function of an exogenous variable. A nonparametric trend test such as...
A magmatic model of Medicine Lake Volcano, California
J.M. Donnelly-Nolan
1988, Journal of Geophysical Research Solid Earth (93) 4412-4420
Medicine Lake volcano is a Pleistocene and Holocene shield volcano of the southern Cascade Range. It is located behind the main Cascade arc in an extensional tectonic setting where high-alumina basalt is the most commonly erupted lava. This basalt is parental to the higher-silica calc-alkaline and tholeiitic lavas that make...
The surface integral approach to Radarclinometry
R.L. Wildey
1988, Earth, Moon and Planets (41) 141-153
Because radarclinometry is fundamentally describable in terms of a nonlinear, first-order, partial differential equation, one expects that it can, in principle, be carried out by direct deterministic integration beginning at a given threshold profile along the azimuthal coordinate. Such a boundary condition could be provided by the altimetry profile obtained...
Origin of metaluminous and alkaline volcanic rocks of the Latir volcanic field, northern Rio Grande rift, New Mexico
C.M. Johnson, P. W. Lipman
1988, Contributions to Mineralogy and Petrology (100) 107-128
Volcanic rocks of the Latir volcanic field evolved in an open system by crystal fractionation, magma mixing, and crustal assimilation. Early high-SiO2 rhyolites (28.5 Ma) fractionated from intermediate compositionmagmas that did not reach the surface. Most precaldera lavas have intermediate-compositions, from olivine basaltic-andesite (53% SiO2) to quartz latite (67% SiO2)....
Petrology of ultramafic xenoliths from Loihi Seamount, Hawaii
D.A. Clague
1988, Journal of Petrology (29) 1161-1186
Ultramafic xenoliths were recovered in four alkalic lava flows from Loihi Seamount at depths between 2200 and 1400m. No xenolith bearing flows were sampled near the summit despite a concentrated dredge program. The flows, three of alkalic basalt and one of basanite, contain common olivine megacrysts and small xenoliths...
Chemical characterization and mutagenic properties of polycyclic aromatic compounds in sediment from tributaries of the Great Lakes
David L. Fabacher, Christopher J. Schmitt, John M. Besser, Michael J. Mac
1988, Environmental Toxicology and Chemistry (7) 529-543
Sediments from four inshore industrial sites and a reference site in the Great Lakes were extracted with solvents and characterized chemically for polycyclic aromatic compounds (PACs). An aqueous phase and a crude organic extract were obtained. The crude organic extract was further resolved into fractions A-2 (polycyclic aromatic hydrocarbons) and...
Retardations in fault creep rates before local moderate earthquakes along the San Andreas fault system, central California
Robert O. Burford
1988, Pure and Applied Geophysics PAGEOPH (126) 499-529
Records of shallow aseismic slip (fault creep) obtained along parts of the San Andreas and Calaveras faults in central California demonstrate that significant changes in creep rates often have been associated with local moderate earthquakes. An immediate postearthquake increase followed by gradual, long-term decay back to a previous background rate...
Tectonic history of the Syria Planum province of Mars
K. L. Tanaka, P. A. Davis
1988, Journal of Geophysical Research Solid Earth (93) 14893-14917
We attribute most of the development of extensive fractures in the Tharsis region to discrete tectonic provinces within the region, rather than to Tharsis as a single entity. One of these provinces is in Syria Planum. Faults and collapse structures in the Syria Planum tectonic province on Mars are grouped...
Generation of pyroclastic flows and surges by hot-rock avalanches from the dome of Mount St. Helens volcano, USA
R.A. Mellors, R. B. Waitt, D. A. Swanson
1988, Bulletin of Volcanology (50) 14-25
Several hot-rock avalanches have occurred during the growth of the composite dome of Mount St. Helens, Washington between 1980 and 1987. One of these occurred on 9 May 1986 and produced a fan-shaped avalanche deposit of juvenile dacite debris together with a more extensive pyroclastic-flow deposit. Laterally thinning deposits and...
Comprehensive method of characteristics models for flow simulation
Chintu Lai
1988, Journal of Hydraulic Engineering (114) 1074-1097
The use of the specified time interval (STI) numerical schemes has been popular in applying the method of characteristics (MOC) to unsteady open‐channel flow problems. Studies and analyses of several variants of the STI schemes have led to the derivation of a new scheme, referred to herein as the multimode...
The Whittier Narrows, California earthquake of October 1, 1987: Preliminary assessment of strong ground motion records
A. G. Brady, E. C. Etheredge, R. L. Porcella
1988, Earthquake Spectra (4) 55-74
More than 250 strong-motion accelerograph stations were triggered by the Whittier Narrows, California, earthquake of 1 October 1987. Considering the number of multichannel structural stations in the area of strong shaking, this set of records is one of the more significant in history. Three networks, operated by the U.S. Geological...
Geochemistry and origin of albite gneisses, northeastern Adirondack Mountains, New York
P.R. Whitney, J.F. Olmsted
1988, Contributions to Mineralogy and Petrology (99) 476-484
Albite gneisses containing up to 8.7 percent Na2O and as little as 0.1% K2O comprise a significant part of the Proterozoic Lyon Mountain Gneiss in the Ausable Forks Quadrangle of the northeastern Adirondacks, New York State. Two distinct types of albite gneisses are present. One is a trondhjemitic leucogneiss (LAG)...
Intermediate-term, pre-earthquake phenomena in California, 1975-1986, and preliminary forecast of seismicity for the next decade
R. L. Wesson, C. Nicholson
1988, Pure and Applied Geophysics PAGEOPH (126) 407-446
Intermediate-term observations preceding earthquakes of magnitude 5.7 or greater in California from 1975 through 1986 suggest that: (1) The sudden appearance of earthquakes in a previously inactive area indicates an increased likelihood of a significant earthquake in that area for a period from days to years; (2) these larger earthquakes...
The radiocarbon budget for Mono Lake: An unsolved mystery
W.S. Broecker, R. Wanninkhof, G. Mathieu, T.-H. Peng, S. Stine, S. Robinson, A. Herczeg, M. Stuiver
1988, Earth and Planetary Science Letters (88) 16-26
Since 1957 the 14C/C ratio of the dissolved inorganic carbon in Mono Lake has risen by about 60‰. The magnitude of this increase is about four times larger than that expected from the invasion of bomb-produced14C from the atmosphere. We have eliminated the following explanations: (1) measurement error, (2) an unusually...
