Modes of development of slope canyons and their relation to channel and levee features on the Ebro sediment apron, off-shore northeastern Spain
S. O'Connell, William B. F. Ryan, W. R. Normark
1987, Marine and Petroleum Geology (4)
Six submarine slope canyons in an area of the northwestern Mediterranean, offshore from the Ebro River and Delta, were surveyed with bathymetric swathmapping (SeaBeam) and mid-range side-looking sonar (SeaMARC I). All of the canyons have slightly winding paths with concave-upwards gradients that are relatively steep shallower than 1,200 m. Two...
EFFECT OF AN ACID RAIN ENVIRONMENT ON LIMESTONE SURFACES.
Victor G. Mossotti, James R. Lindsay, Michael F. Hochella Jr.
1987, Materials Performance (26) 47-52
Salem limestone samples were exposed to weathering for 1 y in several urban and one rural environments. Samples exposed in the rural location were chemically indistinguishable from the freshly quarried limestone, whereas all samples collected from urban exposure sites developed gypsum stains on the ground-facing surfaces where the stones were...
Stochastic simulation of spatially correlated geo-processes
G. Christakos
1987, Mathematical Geology (19) 807-831
In this study, developments in the theory of stochastic simulation are discussed. The unifying element is the notion of Radon projection in Euclidean spaces. This notion provides a natural way of reconstructing the real process from a corresponding process observable on a reduced dimensionality space, where analysis is theoretically easier...
Behavior of sensitivities in the one-dimensional advection-dispersion equation: Implications for parameter estimation and sampling design
Debra S. Knopman, Clifford I. Voss
1987, Water Resources Research (23) 253-272
The spatial and temporal variability of sensitivities has a significant impact on parameter estimation and sampling design for studies of solute transport in porous media. Physical insight into the behavior of sensitivities is offered through an analysis of analytically derived sensitivities for the one-dimensional form of the advection-dispersion equation. When...
Benthic foraminifers on the continental shelf and upper slope, Russian River area, northern California ( USA).
P. J. Quinterno, J.V. Gardner
1987, Journal of Foraminiferal Research (17) 132-152
We analyzed benthic foraminifers from 71 surface samples collected from the sea floor of the continental margin. One hundred and six different taxa were identified, and Q-mode factor analysis was used to identify assemblages. Six foraminiferal assemblage factors explain 94% of the variation in the data matrix. The Inner Shelf...
Valles Marineris, Mars: Wet debris flows and ground ice
Baerbel K. Lucchitta
1987, Icarus (72) 411-429
Detailed study of the Valles Marineris equatorial troughs suggests that the landslides in that area contained water and probably were gigantic wet debris flows: one landslide complex generated a channel that has several bends and extends for 250 km. Further support for water or ice in debris masses includes rounded...
Stratification of a cityscape using census and land use variables for inventory of building materials
G.H. Rosenfield, K. Fitzpatrick-Lins, T. L. Johnson
1987, The Annals of Regional Science (21) 22-33
A cityscape (or any landscape) can be stratified into environmental units using multiple variables of information. For the purposes of sampling building materials, census and land use variables were used to identify similar strata. In the Metropolitan Statistical Area of a cityscape, the census tract is the smallest unit for...
Depth-averaging effects on hydraulic head for media with stochastic hydraulic conductivity
R.L. Naff, A. V. Vecchia
1987, Water Resources Research (23) 561-570
Hydraulic conductivity of a porous medium frequently is considered to be a single realization of a three-dimensional spatial stochastic process. The most common observations of flow in porous media are hydraulic-head measurements obtained from wells which are screened over extensive sections of the medium. These measurements represent, approximately, a one-dimensional...
Unsaturated flow in a centrifugal field: Measurement of hydraulic conductivity and testing of Darcy's Law
John R. Nimmo, J. Rubin, D.P. Hammermeister
1987, Water Resources Research (23) 124-134
A method has been developed to establish steady state flow of water in an unsaturated soil sample spinning in a centrifuge. Theoretical analysis predicts moisture conditions in the sample that depend strongly on soil type and certain operating parameters. For Oakley sand, measurements of flux, water content, and matric potential...
Status of glacial Lake Columbia during the last floods from glacial Lake Missoula
B.F. Atwater
1987, Quaternary Research (27) 182-201
The last floods from glacial Lake Missoula, Montana, probably ran into glacial Lake Columbia, in northeastern Washington. In or near Lake Columbia's Sanpoil arm, Lake Missoula floods dating from late in the Fraser glaciation produced normally graded silt beds that become thinner upsection and which alternate with intervals of progressively...
Studies of Quaternary saline lakes-III. Mineral, chemical, and isotopic evidence of salt solution and crystallization processes in Owens Lake, California, 1969-1971
G.I. Smith, I. Friedman, R. J. McLaughlin
1987, Geochimica et Cosmochimica Acta (51) 811-827
As a consequence of the 1969–1970 flooding of normally dry Owens Lake, a 2.4-m-deep lake formed and 20% of the 2-m-thick salt bed dissolved in it. Its desiccation began August 1969, and salts started crystallizing September 1970, ending August 1971. Mineralogic,...
Influence of late Quaternary climatic changes on geomorphic and pedogenic processes on a desert piedmont, Eastern Mojave Desert, California
S. G. Wells, L. D. McFadden, J. C. Dohrenwend
1987, Quaternary Research (27) 130-146
Radiocarbon dating of late Quaternary deposits and shorelines of Lake Mojave and cation-ratio numerical age dating of stone pavements (Dorn, 1984) on the adjacent Soda Mountains piedmont provide age constraints for alluvial and eolian deposits. These deposits are associated with climatically controlled stands of Lake Mojave during the past 15,000...
Moment tensor solutions estimated using optimal filter theory for 51 selected earthquakes, 1980-1984
S.A. Sipkin
1987, Physics of the Earth and Planetary Interiors (47) 67-79
The 51 global events that occurred from January 1980 to March 1984, which were chosen by the convenors of the Symposium on Seismological Theory and Practice, have been analyzed using a moment tensor inversion algorithm (Sipkin). Many of the events were routinely analyzed as part of the National Earthquake Information...
Transport of reacting solutes subject to a moving dissolution boundary: Numerical methods and solutions
Catherine Willis, Jacob Rubin
1987, Water Resources Research (23) 1561-1574
A moving boundary problem which arises during transport with precipitation-dissolution reactions is solved by three different numerical methods. Two of these methods (one explicit and one implicit) are based on an integral formulation of mass balance and lead to an approximation of a weak solution. These methods are compared to...
CALCULATION OF NONLINEAR CONFIDENCE AND PREDICTION INTERVALS FOR GROUND-WATER FLOW MODELS.
Richard L. Cooley, Aldo V. Vecchia
1987, Water Resources Bulletin (23) 581-599
A method is derived to efficiently compute nonlinear confidence and prediction intervals on any function of parameters derived as output from a mathematical model of a physical system. The method is applied to the problem of obtaining confidence and prediction intervals for manually-calibrated ground-water flow models. To obtain confidence and...
Multiple sources of alkanes in Quaternary oceanic sediment of Antarctica
Keith A. Kvenvolden, John B. Rapp, Margaret Golan-Bac, Frances D. Hostettler
1987, Organic Geochemistry (11) 291-302
Normal alkanes (n-C13n-C36), isoprenoid hydrocarbons (i-C15, i-C16, i-C18, i-C19, and i-C20) triterpanes (C27C32), and (C27C29) are present in low concentrations offshore Antarctica in near-surface, Quaternary sediment of the Wilkes Land continental margin and of the western Ross Sea. The distributions of these...
Sedimentation across the central California oxygen minimum zone: an alternative coastal upwelling sequence
T. L. Vercoutere, H.T. Mullins, K. McDougall, J.B. Thompson
1987, Journal of Sedimentary Petrology (57) 709-722
Distribution, abundance, and diversity of terrigenous, authigenous, and biogenous material provide evidence of the effect of bottom currents and oxygen minimum zone (OMZ) on continental slope sedimentation offshore central California. Box core samples and bottom photographs collected across the oxygen minimum zone of...
Chemical structural studies of natural lignin by dipolar dephasing solid-state 13C nuclear magnetic resonance
Patrick G. Hatcher
1987, Organic Geochemistry (11) 31-39
Two natural lignins, one from a gymnosperm wood the other from angiosperm wood, were examined by conventional solid-state and dipolar dephasing 13C nuclear magnetic resonance (NMR) techniques. The results obtained from both techniques show that the structure of natural lignins is consistent with models of softwood and hardwood lignin. The dipolar...
Paint chip poisoning of Laysan albatross at Midway Atoll
L. Sileo, S.I. Fefer
1987, Journal of Wildlife Diseases (23) 432-437
Epizootic mortality occurred in Laysan albatross (Diomedea immutabilis) fledgings at Midway Atoll in 1983. Heavy metal toxicity from ingestion of weathered paint chips was one of the causes. Sick albatrosses were unable to retract their wings, causing a 'droop-wing' appearance. Five normal and 12 droop-winged fledglings were captured, killed, and...
Trend analysis of monthly sulfur dioxide emissions in the conterminous United States, 1975-1984
H.F. Lins
1987, Atmospheric Environment (21) 2297-2309
Trends in monthly sulfur dioxide emissions for the 48 conterminous United States during the decade 1975-1984 are identified using a robust nonparametric procedure. Statistically significant downward trends are indicated in 32 States, upward trends appear in 10 States, and no significant trend is apparent in six States. Geographically, a distinct...
Basin-ring spacing on the Moon, Mercury, and Mars
R.J. Pike, P. D. Spudis
1987, Earth, Moon and Planets (39) 129-194
Radial spacing between concentric rings of impact basins that lack central peaks is statistically similar and nonrandom on the Moon, Mercury, and Mars, both inside and outside the main ring. One spacing interval, (2.0 ?? 0.3)0.5D, or an integer multiple of it, dominates most basin rings. Three analytical approaches yield...
Use of focal mechanisms to determine stress: A control study.
A.J. Michael
1987, Journal of Geophysical Research Solid Earth (92) 357-368
To allow focal mechanisms to be inverted for the stress field requires a different inversion algorithm than for slickenside data because focal mechanisms do not represent fault slip data unless one can decide which nodal plane is the fault plane. If one can decide which nodal plane is the fault...
Geological setting of U.S. fossil fuels.
C.D. Masters, R. F. Mast
1987, Episodes (10) 308-313
The USA has a special position in terms of fossil fuel development. Not only is it one of the most important nations in terms of resources of oil, gas and coal, but it has also been by far the dominant producer and consumer. In this thorough review of the regional...
Gravity anomaly at a Pleistocene lake bed in NW Alaska interpreted by analogy with Greenland's Lake Taserssauq and its floating ice tongue
D.F. Barnes
1987, Journal of Geophysical Research Solid Earth (92) 8976-8984
A possible example of a very deep glacial excavation is provided by a distinctive gravity low located at the front of a valley glacier that once flowed into glacial Lake Aniuk (formerly Lake Noatak) in the western Brooks Range. Geologic and geophysical data suggest that sediments or ice filling a...
Methylation patterns of aquatic humic substances determined by13C NMR spectroscopy
Kevin A. Thorn, C. Steelink, Robert L. Wershaw
1987, Organic Geochemistry (11) 123-137
13C NMR spectroscopy is used to examine the hydroxyl group functionality of a series of humic and fulvic acids from different aquatic environments. Samples first are methylated with13C-labeled diazomethane. The NMR spectra of the diazomethylated samples allow one to distinguish between methyl esters of carboxylic acids, methyl ethers of phenolic...
