The relationship between gorgonian coral (Cnidaria: Gorgonacea) diseases and African dust storms
J. R. Weir-Brush, V.H. Garrison, G.W. Smith, E.A. Shinn
2004, Aerobiologia (20) 119-126
The number of reports of coral diseases has increased throughout the world in the last 20 years. Aspergillosis, which primarily affects Gorgonia ventalina and G. flabellum, is one of the few diseases to be characterized. This disease is caused by Aspergillus sydowii, a terrestrial fungus with a worldwide distribution. Upon...
Factors influencing occupancy of nest cavities in recently burned forests
V.A. Saab, J. Dudley, W.L. Thompson
2004, Conference Paper, Condor
Recently burned forests in western North America provide nesting habitat for many species of cavity-nesting birds. However, little is understood about the time frame and the variables affecting occupancy of postfire habitats by these birds. We studied factors influencing the occupancy and reuse of nest cavities from 1-7 years after...
Toward mapping surface deformation in three dimensions using InSAR
Tim J. Wright, Barry E. Parsons, Zhong Lu
2004, Geophysical Research Letters (31)
One of the limitations of deformation measurements made with interferometric synthetic aperture radar (InSAR) is that an interferogram only measures one component of the surface deformation — in the satellite's line of sight. We investigate strategies for mapping surface deformation in three dimensions by using multiple interferograms, with different imaging...
Contrasting glacial/interglacial regimes in the western Arctic Ocean as exemplified by a sedimentary record from the Mendeleev Ridge
L. Polyak, W.B. Curry, D. A. Darby, J. Bischof, T. M. Cronin
2004, Palaeogeography, Palaeoclimatology, Palaeoecology (203) 73-93
Distinct cyclicity in lithology and microfaunal distribution in sediment cores from the Mendeleev Ridge in the western Arctic Ocean (water depths ca. 1. 5 km) reflects contrasting glacial/interglacial sedimentary patterns. We conclude that during major glaciations extremely thick pack ice or ice shelves covered the western Arctic Ocean and its...
The bioavailability of chemicals in soil for earthworms
R. Lanno, J. Wells, Jason M. Conder, K. Bradham, N. Basta
2004, Conference Paper, Ecotoxicology and Environmental Safety
The bioavailability of chemicals to earthworms can be modified dramatically by soil physical/chemical characteristics, yet expressing exposure as total chemical concentrations does not address this problem. In order to understand the effects of modifying factors on bioavailability, one must measure and express chemical bioavailability to earthworms in a consistent, logical...
Historical perspectives on the concept of ecosystem degradation
W. L. Halvorson
2004, Conference Paper, International Journal of Ecology and Environmental Sciences
The concept of environmental degradation has evolved with the development of human society and settlement. In early human development, tribes went through a series of cycles of taming or developing mastery over the environment, to utilizing the resources of that environment until they could no longer support the population, which...
Spawning ecology of finespotted Snake River cutthroat trout in spring streams of the Salt River valley, Wyoming
M. P. Joyce, W.A. Hubert
2004, Western North American Naturalist (64) 78-85
We studied spawning ecology of cutthroat trout (Oncorhynchus clarki) in streams that originate as springs along the Salt River, a Snake River tributary in western Wyoming. We assessed (1) relative numbers of upstream-migrant and resident adults present during the spawning period in spring streams, (2) influence of habitat modification on...
Complex proximal deposition during the Plinian eruptions of 1912 at Novarupta, Alaska
Bruce F. Houghton, C. J. N. Wilson, J. Fierstein, W. Hildreth
2004, Bulletin of Volcanology (66) 95-133
Proximal (<3 km) deposits from episodes II and III of the 60-h-long Novarupta 1912 eruption exhibit a very complex stratigraphy, the result of at least four transport regimes and diverse depositional mechanisms. They contrast with the relatively simple stratigraphy (and inferred emplacement mechanisms) for the previously documented, better known, medial-distal...
Dynamics of intertidal foraging by coastal brown bears in Southwestern Alaska
T. S. Smith, Steven T. Partridge
2004, Journal of Wildlife Management (68) 233-240
Shoreline areas provide early season foraging opportunities for coastal bears in Alaska. We investigated use by brown bears (Ursus arctos) of soft-shelled (Mya arenaria) and Pacific razor (Siliqua patula) clams at Katmai National Park, Alaska, USA, to identify the potential importance of these clams to bears. We used direct observations...
Mapping of the Culann-Tohil region of Io from Galileo imaging data
D.A. Williams, Paul M. Schenk, Jeffrey M. Moore, Laszlo P. Keszthelyi, Elizabeth P. Turtle, Windy L. Jaeger, Jani Radebaugh, Moses P. Milazzo, Rosaly Lopes, Ronald Greeley
2004, Icarus (169) 80-97
We have used Galileo spacecraft data to produce a geomorphologic map of the Culann–Tohil region of Io's antijovian hemisphere. This region includes a newly discovered shield volcano, Tsũi Goab Tholus and a neighboring bright flow field, Tsũi Goab Fluctus, the active Culann Patera and the enigmatic Tohil Mons-Radegast Patera–Tohil Patera complex. Analysis...
Testing density-dependent groundwater models: Two-dimensional steady state unstable convection in infinite, finite and inclined porous layers
D. Weatherill, C.T. Simmons, C.I. Voss, N.I. Robinson
2004, Advances in Water Resources (27) 547-562
This study proposes the use of several problems of unstable steady state convection with variable fluid density in a porous layer of infinite horizontal extent as two-dimensional (2-D) test cases for density-dependent groundwater flow and solute transport simulators. Unlike existing density-dependent model benchmarks, these...
Effects of model sensitivity and nonlinearity on nonlinear regression of ground water flow
R. M. Yager
2004, Ground Water (42) 390-400
Nonlinear regression is increasingly applied to the calibration of hydrologic models through the use of perturbation methods to compute the Jacobian or sensitivity matrix required by the Gauss-Newton optimization method. Sensitivities obtained by perturbation methods can be less accurate than those obtained by direct differentiation, however, and concern has arisen...
Effects of distance from cattle water developments on grassland birds
A.L. Fontaine, P.L. Kennedy, Douglas H. Johnson
2004, Journal of Range Management (57) 238-242
Many North American grassland bird populations appear to be declining, which may be due to changes in grazing regimes on their breeding areas. Establishment of water developments and confining cattle (Bos taurus L.) to small pastures often minimizes spatial heterogeneity of cattle forage consumption, which may lead to uniformity in...
Temporal and spatial patterns in emergence and early survival of perennial plants in the Sonoran Desert
Janice E. Bowers, R. M. Turner, T.L. Burgess
2004, Plant Ecology (172) 107-119
Seedling emergence and survival of 15 perennial species were studied for six years in a 557-m2 permanent plot at Tumamoc Hill, Arizona, USA, an ungrazed site in the northern Sonoran Desert. The minimum rain required for germination and emergence ranged from 17.5 to 35.6 mm. Few species emerged in every...
Holocene loess deposition and soil formation as competing processes, Matanuska Valley, southern Alaska
D.R. Muhs, J. P. McGeehin, J. Beann, E. Fisher
2004, Quaternary Research (61) 265-276
Although loess-paleosol sequences are among the most important records of Quaternary climate change and past dust deposition cycles, few modern examples of such sedimentation systems have been studied. Stratigraphic studies and 22 new accelerator mass spectrometry radiocarbon ages from the Matanuska Valley in southern Alaska show that loess deposition there...
Coal facies studies in the eastern United States
J.C. Hower, C.F. Eble
2004, International Journal of Coal Geology (58) 3-22
Coals in the eastern United States (east of the Mississippi River) have been the subject of a number of coal facies studies, going back to the 19th century. Such studies would not necessarily fall within a strict modern classification of coal facies studies, but if a study encompassed some aspects...
The origin and mechanisms of salinization of the Lower Jordan River
E. Farber, A. Vengosh, I. Gavrieli, Amarisa Marie, T.D. Bullen, B. Mayer, R. Holtzman, M. Segal, U. Shavit
2004, Geochimica et Cosmochimica Acta (68) 1989-2006
The chemical and isotopic (87Sr/86Sr, ??11B, ??34Ssulfate, ??18Owater, ??15Nnitrate) compositions of water from the Lower Jordan River and its major tributaries between the Sea of Galilee and the Dead Sea were determined in order to reveal the origin of the salinity of the Jordan River. We identified three separate hydrological...
Climate change in southern Illinois, USA, based on the age and δ13C of organic matter in cave sediments
Samuel V. Panno, B. Brandon Curry, Hongfang Wang, Keith C. Hackley, Chao-Li Liu, Craig Lundstrom, Juanzuo Zhou
2004, Quaternary Research (61) 301-313
Matrix-supported diamicton and uniform to laminated, silty, fine-grained sediment deposited from about 42,500 to 27,600 cal yr B.P. under slackwater conditions nearly filled two caves in southwestern Illinois. At some point, most of the sediment was flushed from the caves and from about 22,700 to 4000 cal yr B.P., floods...
Historical trends in occurrence and atmospheric inputs of halogenated volatile organic compounds in untreated ground water used as a source of drinking water
S.D. Shapiro, E. Busenberg, M. J. Focazio, Niel Plummer
2004, Science of the Total Environment (321) 201-217
Analyses of samples of untreated ground water from 413 community-, non-community- (such as restaurants), and domestic-supply wells throughout the US were used to determine the frequency of detection of halogenated volatile organic compounds (VOCs) in drinking-water sources. The VOC data were compiled from archived...
Assessing development pressure in the Chesapeake Bay watershed: An evaluation of two land-use change models
Peter R. Claggett, Claire A. Jantz, S.J. Goetz, C. Bisland
2004, Environmental Monitoring and Assessment (94) 129-146
Natural resource lands in the Chesapeake Bay watershed are increasingly susceptible to conversion into developed land uses, particularly as the demand for residential development grows. We assessed development pressure in the Baltimore-Washington, DC region, one of the major urban and suburban centers in the watershed. We explored the utility of...
Estimates of diffuse phosphorus sources in surface waters of the United States using a spatially referenced watershed model
R. B. Alexander, R. A. Smith, G. E. Schwarz
2004, Water Science and Technology (49) 1-10
The statistical watershed model SPARROW (SPAtially Referenced Regression On Watershed attributes) was used to estimate the sources and transport of total phosphorus (TP) in surface waters of the United States. We calibrated the model using stream measurements of TP from 336 watersheds of mixed land use and spatial data on...
Tidal oscillation of sediment between a river and a bay: A conceptual model
N. K. Ganju, D. H. Schoellhamer, J.C. Warner, M.F. Barad, S.G. Schladow
2004, Estuarine, Coastal and Shelf Science (60) 81-90
A conceptual model of fine sediment transport between a river and a bay is proposed, based on observations at two rivers feeding the same bay. The conceptual model consists of river, transitional, and bay regimes. Within the transitional regime, resuspension, advection, and deposition create a mass of sediment that oscillates...
Early environment and recruitment of black brant (Branta bernicla nigricans) into the breeding population
James S. Sedinger, Mark P. Herzog, David H. Ward
2004, The Auk (121) 68-73
In geese, growth regulates survival in the first year. We examined whether early growth, which is primarily governed by environmental conditions, also affects the probability that individuals that survive their first year enter the breeding population. We used logistic regression on a sample of Black Brant (Branta bernicla nigricans) that...
Structural model of the San Bernardino basin, California, from analysis of gravity, aeromagnetic, and seismicity data
M. Anderson, J. Matti, R. Jachens
2004, Journal of Geophysical Research B: Solid Earth (109)
The San Bernardino basin is an area of Quaternary extension between the San Jacinto and San Andreas Fault zones in southern California. New gravity data are combined with aeromagnetic data to produce two- and three-dimensional models of the basin floor. These models are used to identify specific faults that have...
Noise in two-color electronic distance meter measurements revisited
J. Langbein
2004, Journal of Geophysical Research B: Solid Earth (109)
Frequent, high-precision geodetic data have temporally correlated errors. Temporal correlations directly affect both the estimate of rate and its standard error; the rate of deformation is a key product from geodetic measurements made in tectonically active areas. Various models of temporally correlated errors are developed and these provide relations between...
