An automatic optimum kernel-size selection technique for edge enhancement
Pat S. Chavez Jr., Brian P. Bauer
1982, Remote Sensing of Environment (12) 23-38
Edge enhancement is a technique that can be considered, to a first order, a correction for the modulation transfer function of an imaging system. Digital imaging systems sample a continuous function at discrete intervals so that high-frequency information cannot be recorded at the same precision as lower frequency data. Because...
Volcanoes
Robert I. Tilling
1982, Report
Volcanoes destroy and volcanoes create. The catastrophic eruption of Mount St. Helens on May 18, 1980, made clear the awesome destructive power of a volcano. Yet, over a time span longer than human memory and record, volcanoes have played a key role in forming and modifying the planet upon which...
Sources, sinks and storage of river sediments in the Atlantic drainage of the United States
R.H. Meade
1982, Journal of Geology (90) 235-252
The history of sediment and its movement in the Atlantic drainage demonstrate some of the difficulties of modeling sediment on a river-basin scale. Soil erosion was accelerated by a factor of at least 10 when European settlers cleared forests and planted crops. Although increasing soil-conservation practice and decreasing crop farming...
Mineralogy and stable isotope geochemistry of hydrothermally altered oceanic rocks
D.S. Stakes, J. R. O’Neil
1982, Earth and Planetary Science Letters (57) 285-304
Mineralogical and isotopic variations observed in altered glassy and crystalline rocksfrom the East Pacific Rise and the Mid-Atlantic Ridge provide information about the temperatures of alteration and seawater/rock ratios for various hydrothermal regimes within the oceanic crust. A systematic increase in alteration temperature is evident for the glassy rocksin the...
Mineralogy and geochemistry of Fe-Ti oxide and apatite (nelsonite) deposits and evaluation of the liquid immiscibility hypothesis.
A. Kolker
1982, Economic Geology (77) 1146-1158
Modal mineralogy determined for 32 Fe-Ti oxide and apatite rocks from localities in Virginia, New York, Quebec, Norway, and Sweden largely supports the 2:1 oxide:apatite ratio suggested as a eutectic mixture by Philpotts (1967). A fairly consistent suite of accessory minerals, including biotite, clinoamphibole, spinel, zircon, and sulfides, is present....
Preliminary model of regional Mesozoic groundwater flow and uranium deposition in the Colorado Plateau.
R.F. Sanford
1982, Geology (10) 348-352
Qualitative and numerical simulation of regional groundwater flow in the Colorado Plateau during Late Jurassic and Early Cretaceous time has led to a model of U deposition in areas of upwelling solutions. Palaeographic reconstruction shows that surface drainage and groundwater flow was generally to the NE and E. Groundwater flowing...
Benthic phosphorus regeneration in the Potomac River Estuary
E. Callender
1982, Hydrobiologia (91-92) 431-446
The flux of dissolved reactive phosphate from Potomac riverine and estuarine sediments is controlled by processes occurring at the water-sediment interface and within surficial sediment. In situ benthic fluxes (0.1 to 2.0 mmoles m-2 day-1) are generally five to ten times higher than calculated diffusive fluxes (0.020 to 0.30 mmoles...
Huge landslide blocks in the growth of piton de la fournaise, La réunion, and Kilauea volcano, Hawaii
Wendell A. Duffield, Laurent Stieltjes, Jacques Varet
1982, Journal of Volcanology and Geothermal Research (12) 147-160
Piton de la Fournaise, on the island of La Réunion, and Kilauea volcano, on the island of Hawaii, are active, basaltic shield volcanoes growing on the flanks of much larger shield volcanoes in intraplate tectonic environments. Past studies have shown that the average rate of magma production and the chemistry...
Deep structure and evolution of the Carolina Trough
D. R. Hutchinson, J. A. Grow, Kim D. Klitgord, B.A. Swift
1982, Book chapter, Studies in continental margin geology
Multichannel seismic-reflection data together with two-dimensional gravity and magnetic models suggest that the crustal structure off North Carolina consists of normal continental crust landward of the Brunswick magnetic anomaly (BMA), rift-stage crust in the 80-km-wide zone between the BMA and the East Coast magnetic anomaly (ECMA), and normal oceanic crust...
Numerical models of hydrothermal circulation for the intrusion zone at an ocean ridge axis
P.L. Patterson, R.P. Lowell
Kent A. Fanning, Frank T. Manheim, editor(s)
1982, Book chapter, The dynamic environment of the ocean floor
No abstract available....
Modeling of tidal and residual circulation in San Francisco Bay, California
R. T. Cheng
1982, Conference Paper, Proceedings, Seminar on 2-D Flows
Several numerical models have been developed and implemented to simulate tidal and residual circulation in San Francisco Bay. Because of a broad distribution in time scales, hydrodynamic models must be formulated to account for the proper time and spatial scales which dominate the transport processes. A complete current survey of...
Modeling of estuarine hydrodynamics and field data requirements
R. T. Cheng, R. A. Walters
1982, Finite Methods in Fluids (4) 89-108
No abstract available....
Low-frequency variations in sea level and currents in south San Francisco Bay
Roy A. Walters
1982, Journal of Physical Oceanography (12) 658-668
In order to examine physical process in the subtidal time range, sea-level and current meter data for south San Francisco Bay (South Bay) were filtered using a low-pass digital filter to remove tidal period variations. and then subjected to an empirical orthogonal function analysis. For the sea-level data, there is...
Population modeling for furbearer management
Douglas H. Johnson
G.C. Sanderson, editor(s)
1982, Book chapter, Midwest Furbearer Management. N. Central Sec., Central Mountains and Plains Sec., and KS.
The management of furbearers has become increasingly complex as greater demands are placed on their populations. Correspondingly, needs for information to use in management have increased. Inadequate information leads the manager to err on the conservative side; unless the size of the 'harvestable surplus' is known, the population cannot be...
Relation between freshwater flow and salinity distributions in the Alafia River, Bullfrog Creek, and Hillsborough Bay, Florida
R.F. Giovannelli, Southwest Florida Water Management District.
1981, Water-Resources Investigations Report 80-102
Data on streamflow, tide stage, specific conductance, and chloride concentration were collected in the Alafia River and Bullfrog Creek to describe the salinity and physical characteristics of the saltwater wedge. The location of the saltwater-freshwater interface for both streams was described by multiple regression equations involving streamflow and tide stage....
Hydrology and model of North Fork Solomon River Valley, Kirwin Dam to Waconda Lake, north-central Kansas
Donald G. Jorgensen, Lloyd E. Stullken
1981, Irrigation Series 6
The alluvial valley of the North Fork Solomon River is an important agricultural area. Reservoir releases diverted below Kirwin Dam are the principal source of irrigation water. During the 1970'S, severe water shortages occurred in Kirwin Reservoir and other nearby reservoirs as a result of an extended drought. Some evidence...
Water resources inventory of Connecticut Part 7: upper Connecticut River basin
Robert B. Ryder, Mendall P. Thomas, Lawrence A. Weiss
1981, Connecticut Water Resources Bulletin 24
The 508 square miles of the upper Connecticut River basin in north-central Connecticut include the basins of four major tributaries: the Scantic, Park, and Hockanum Rivers, and the Farmington River downstream from Tariffville. Precipitation over this area averaged 44 inches per year during 1931-60. In this period, an additional 3,800...
The structure of western warbler assemblages: Analysis of foraging behavior and habitat selection in Oregon
Michael L. Morrison
1981, The Auk (98) 578-588
This study examines the foraging behavior and habitat selection of a MacGillivray's (Oporornis tolmiei)-Orange-crowned (Vermivora celata)-Wilson's (Wilsonia pusilla) warbler assemblage that occurred on early-growth clearcuts in western Oregon during breeding. Sites were divided into two groups based on the presence or absence of deciduous trees. Density estimates for each species...
The Mayfield method of estimating nesting success: A model, estimators and simulation results
Gary L. Hensler, J.D. Nichols
1981, The Wilson Bulletin (93) 42-53
Using a nesting model proposed by Mayfield we show that the estimator he proposes is a maximum likelihood estimator (m.l.e.). M.l.e. theory allows us to calculate the asymptotic distribution of this estimator, and we propose an estimator of the asymptotic variance. Using these estimators we give approximate confidence...
Censusing wading bird colonies: An update on the 'flight-line' count method
R.M. Erwin
1981, Colonial Waterbirds (4) 91-95
1. Thirteen mixed-species heronries (10 in Florida, two in Virginia, one in North Carolina) were studied in 1980 as part of a project begun in 1979 aimed at evaluating the 'flight-line' census method..2. Standardized counts of Snowy and Cattle Egrets, Louisiana and Little Blue Herons flying to and from the...
Estimates of avian population trends from the North American Breeding Bird Survey
P.H. Geissler, B.R. Noon
C. John Ralph, J. Michael Scott, editor(s)
1981, Book chapter, Estimating Numbers of Terrestrial Birds
One of the major purposes of bird population studies is to document changes in population size over a period of years. The traditional method used in Europe and North America to detect population change is to calculate annual ratios. However, this method can produce spurious results when ratios...
Analysis of bird survey data using a modification of Emlen's method
F. L. Ramsey, J. M. Scott
C. John Ralph, J. Michael Scott, editor(s)
1981, Book chapter, Estimating Numbers of Terrestrial Birds
The terminal Eocene event and the Polish connection
J. A. Van Couvering, M.-P. Aubry, W.A. Berggren, J.P. Bujak, C. W. Naeser, T. Wieser
1981, Palaeogeography, Palaeoclimatology, Palaeoecology (36) 321-362
The Eocene/Oligocene boundary in Europe is marked by major discontinuities in all environments: the “Grande Coupure” in continental mammals; the elimination of semitropical elements from high-latitude floras; the virtually complete replacement of the shallow-marine malacofauna; and an extraordinary downslope excursion of carbonate deposition in deep-ocean basins (drop in the CCD)....
Plumbotectonics-the model
R. E. Zartman, B. R. Doe
1981, Tectonophysics (75) 135-162
Plumbotectonics is an attempt to model the geochemical behaviour of U, Th and Pb, among major terrestrial reservoirs in agreement with observational data. By recycling rock through the orogenic environment, a dynamically communicating upper crust, lower crust, and mantle can produce the required patterns of lead-isotope evolution. ...
Composition of the earth's upper mantle-I. Siderophile trace elements in ultramafic nodules
J. W. Morgan, G.A. Wandless, R.K. Petrie, A.J. Irving
1981, Tectonophysics (75) 47-67
Seven siderophile elements (Au, Ge, Ir, Ni, Pd, Os, Re) were determined by radiochemical neutron activation analysis in 19 ultramafic rocks, which are spinel lherzollites-xenoliths from North and Central America, Hawaii and Australia, and garnet Iherzolitexenoliths from Lesotho.Abundances of the platinum metals are very uniform in spinel lherzolites averaging 3.4...
