Primary production in an impounded baldcypress swamp (Taxodium distichum) at the northern limit of the range
B.A. Middleton, K.L. McKee
2005, Conference Paper, Wetlands Ecology and Management
The ability of baldcypress (Taxodium distichum)swamps to maintain themselves near the northern limit of their range depends on their levels of production, which is not only are response to climate but also to local environmental factors(e.g., impoundment). We asked if primary production was reduced under impounded conditions and if species'...
Single-pass versus two-pass boat electrofishing for characterizing river fish assemblages: Species richness estimates and sampling distance
M. R. Meador
2005, Transactions of the American Fisheries Society (134) 59-67
Determining adequate sampling effort for characterizing fish assemblage structure in nonwadeable rivers remains a critical issue in river biomonitoring. Two-pass boat electrofishing data collected from 500-1,000-m-long river reaches as part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program were analyzed to assess the efficacy of single-pass boat electrofishing....
Mapping the invasive species, Chinese tallow, with EO1 satellite Hyperion hyperspectral image data and relating tallow occurrences to a classified Landsat Thematic Mapper land cover map
Elijah W. Ramsey III, A. Rangoonwala, G. Nelson, R. Ehrlich
2005, International Journal of Remote Sensing (26) 1637-1657
Our objective was to provide a realistic and accurate representation of the spatial distribution of Chinese tallow (Triadica sebifera) in the Earth Observing 1 (EO1) Hyperion hyperspectral image coverage by using methods designed and tested in previous studies. We transformed, corrected, and normalized Hyperion reflectance image data into composition images...
Tree mortality, canopy turnover, and woody detritus in old cove forests of the southern Appalachians
Richard T. Busing
2005, Ecology (86) 73-84
A long-term study of tree mortality, canopy turnover, and coarse woody detritus inputs was conducted in cove forests of the Great Smoky Mountains, Tennessee, USA. Seven old-growth stands were studied over a 10-yr period using 0.6–1.0 ha plots. Annual mortality of trees >10 cm dbh was 0.5–1.4% among stands (mean...
Limiting similarity and functional diversity along environmental gradients
D.W. Schwilk, D. D. Ackerly
2005, Ecology Letters (8) 272-281
Recent developments in community models emphasize the importance of incorporating stochastic processes (e.g. ecological drift) in models of niche-structured community assembly. We constructed a finite, spatially explicit, lottery model to simulate the distribution of species in a one-dimensional landscape with an underlying gradient in environmental conditions. Our framework combines the...
Prey consumption and energy transfer by marine birds in the Gulf of Alaska
G.L. Hunt Jr., G.S. Drew, J. Jahncke, John F. Piatt
2005, Conference Paper, Deep-Sea Research Part II: Topical Studies in Oceanography
We investigated prey consumption by marine birds and their contribution to cross-shelf fluxes in the northern Gulf of Alaska. We utilized data from the North Pacific Pelagic Seabird Database for modeling energy demand and prey consumption. We found that prey consumption by marine birds was much greater over the continental...
Seasonal to interannual morphodynamics along a high-energy dissipative littoral cell
P. Ruggiero, G. M. Kaminsky, G. Gelfenbaum, B. Voigt
2005, Journal of Coastal Research (21) 553-578
A beach morphology monitoring program was initiated during summer 1997 along the Columbia River littoral cell (CRLC) on the coasts of northwest Oregon and southwest Washington, USA. This field program documents the seasonal through interannual morphological variability of these high-energy dissipative beaches over a variety of spatial scales. Following the...
Orientation of three-component geophones in the San Andreas Fault observatory at depth Pilot Hole, Parkfield, California
V. Oye, W.L. Ellsworth
2005, Bulletin of the Seismological Society of America (95) 751-758
To identify and constrain the target zone for the planned SAFOD Main Hole through the San Andreas Fault (SAF) near Parkfield, California, a 32-level three-component (3C) geophone string was installed in the Pilot Hole (PH) to monitor and improve the locations of nearby earthquakes. The orientation of the 3C geophones...
An approach toward a combined scheme for the petrographic classification of fly ash: Revision and clarification
J.C. Hower, I. Suarez-Ruiz, Maria Mastalerz
2005, Energy and Fuels (19) 653-655
Hower and Mastalerz's classification scheme for fly ash is modified to make more widely acceptable. First, proper consideration is given to the potential role of anthracite in the development of isotropic and anisotropic chars. Second, the role of low-reflectance inertinite in producing vesicular chars is noted. It is shown that...
Bedrock erosion surface beneath the rocky flats alluvial fan, Jefferson and Boulder counties, Colorado
D. H. Knepper Jr.
2005, Mountain Geologist (42) 1-10
The early Pleistocene Rocky Flats alluvial fan formed at the mouth of unglaciated Coal Creek Canyon along the eastern flank of the Colorado Front Range. The fan consists of boulder, cobble, and pebble gravel deposited on an erosional surface cut on tilted Mesozoic sedimentary strata. A north-trending hogback of steeply...
Earthquakes: Predicting the unpredictable?
Susan E. Hough
2005, Geotimes (50)
The earthquake prediction pendulum has swung from optimism in the 1970s to rather extreme pessimism in the 1990s. Earlier work revealed evidence of possible earthquake precursors: physical changes in the planet that signal that a large earthquake is on the way. Some respected earthquake scientists argued that earthquakes are likewise...
Interferometric synthetic aperture radar study of Okmok volcano, Alaska, 1992-2003: Magma supply dynamics and postemplacement lava flow deformation
Z. Lu, Timothy Masterlark, Daniel Dzurisin
2005, Journal of Geophysical Research B: Solid Earth (110) 1-18
Okmok volcano, located in the central Aleutian arc, Alaska, is a dominantly basaltic complex topped with a 10-km-wide caldera that formed circa 2.05 ka. Okmok erupted several times during the 20th century, most recently in 1997; eruptions in 1945, 1958, and 1997 produced lava flows within the caldera. We used...
Channelized lava flows at the East Pacific Rise crest 9°-10°N: the importance of off-axis lava transport in developing the architecture of young oceanic crust
S.A. Soule, D.J. Fornari, M.R. Perfit, M.A. Tivey, W.I. Ridley, Hans Schouten
2005, Geochemistry, Geophysics, Geosystems (6)
Submarine lava flows are the building blocks of young oceanic crust. Lava erupted at the ridge axis is transported across the ridge crest in a manner dictated by the rheology of the lava, the characteristics of the eruption, and the topography it encounters. The resulting lava flows can vary dramatically...
A simulation of the hydrothermal response to the Chesapeake Bay bolide impact
W. E. Sanford
2005, Geofluids (5) 185-201
Groundwater more saline than seawater has been discovered in the tsunami breccia of the Chesapeake Bay impact Crater. One hypothesis for the origin of this brine is that it may be a liquid residual following steam separation in a hydrothermal system that evolved following the impact. Initial scoping calculations have...
Human land use influences chronic wasting disease prevalence in mule deer
Matthew L. Farnsworth, L.L. Wolfe, N.T. Hobbs, K.P. Burnham, E.S. Williams, D.M. Theobald, M.M. Conner, M.W. Miller
2005, Ecological Applications (15) 119-126
Human alteration of landscapes can affect the distribution, abundance, and behavior of wildlife. We explored the effects of human land use on the prevalence of chronic wasting disease (CWD) in mule deer (Odocoileus hemionus) populations residing in north-central Colorado. We chose best approximating models estimating CWD prevalence in relation to...
The ubiquitous nature of accessory calcite in granitoid rocks: Implications for weathering, solute evolution, and petrogenesis
A. F. White, M. S. Schulz, J. B. Lowenstern, D.V. Vivit, T.D. Bullen
2005, Geochimica et Cosmochimica Acta (69) 1455-1471
Calcite is frequently cited as a source of excess Ca, Sr and alkalinity in solutes discharging from silicate terrains yet, no previous effort has been made to assess systematically the overall abundance, composition and petrogenesis of accessory calcite in granitoid rocks. This study addresses this issue by analyzing a worldwide...
"Sour gas" hydrothermal jarosite: Ancient to modern acid-sulfate mineralization in the southern Rio Grande Rift
V.W. Lueth, R. O. Rye, L. Peters
2005, Chemical Geology (215) 339-360
As many as 29 mining districts along the Rio Grande Rift in southern New Mexico contain Rio Grande Rift-type (RGR) deposits consisting of fluorite-barite??sulfide-jarosite, and additional RGR deposits occur to the south in the Basin and Range province near Chihuahua, Mexico. Jarosite occurs in many of these deposits as a...
Assessing contaminant sensitivity of endangered and threatened aquatic species: Part I. Acute toxicity of five chemicals
F.J. Dwyer, F.L. Mayer, L.C. Sappington, D.R. Buckler, C.M. Bridges, I.E. Greer, D.K. Hardesty, C.E. Henke, C.G. Ingersoll, J.L. Kunz, D.W. Whites, T. Augspurger, D.R. Mount, K. Hattala, G.N. Neuderfer
2005, Archives of Environmental Contamination and Toxicology (48) 143-154
Assessment of contaminant impacts to federally identified endangered, threatened and candidate, and state-identified endangered species (collectively referred to as "listed" species) requires understanding of a species' sensitivities to particular chemicals. The most direct approach would be to determine the sensitivity of a listed species to a particular contaminant or perturbation....
The accuracy of matrix population model projections for coniferous trees in the Sierra Nevada, California
P. J. van Mantgem, N.L. Stephenson
2005, Journal of Ecology (93) 737-747
1 We assess the use of simple, size-based matrix population models for projecting population trends for six coniferous tree species in the Sierra Nevada, California. We used demographic data from 16 673 trees in 15 permanent plots to create 17 separate time-invariant, density-independent population projection models, and determined differences between...
Evidence for a global seismic-moment release sequence
C. G. Bufe, D. M. Perkins
2005, Bulletin of the Seismological Society of America (95) 833-843
Temporal clustering of the larger earthquakes (foreshock-mainshock-aftershock) followed by relative quiescence (stress shadow) are characteristic of seismic cycles along plate boundaries. A global seismic-moment release history, based on a little more than 100 years of instrumental earthquake data in an extended version of the catalog of Pacheco and Sykes (1992),...
Aeolian processes at the Mars Exploration Rover Meridiani Planum landing site
R. Sullivan, D. Banfield, J.F. Bell III, W. Calvin, D. Fike, M. Golombek, R. Greeley, J. Grotzinger, Kenneth E. Herkenhoff, D. Jerolmack, M. Malin, D. Ming, Laurence A. Soderblom, S. W. Squyres, S. Thompson, W.A. Watters, C.M. Weitz, A. Yen
2005, Nature (436) 58-61
The martian surface is a natural laboratory for testing our understanding of the physics of aeolian (wind-related) processes in an environment different from that of Earth. Martian surface markings and atmospheric opacity are time-variable, indicating that fine particles at the surface are mobilized regularly by wind. Regolith (unconsolidated surface material)...
A statistical approach to estimate the 3D size distribution of spheres from 2D size distributions
M. Kong, R.N. Bhattacharya, C. James, A. Basu
2005, Geological Society of America Bulletin (117) 244-249
Size distribution of rigidly embedded spheres in a groundmass is usually determined from measurements of the radii of the two-dimensional (2D) circular cross sections of the spheres in random flat planes of a sample, such as in thin sections or polished slabs. Several methods have been devised to find a...
Exposing extinction risk analysis to pathogens: Is disease just another form of density dependence?
Leah R. Gerber, Hamish McCallum, Kevin D. Lafferty, John L. Sabo, Andy Dobson
2005, Ecological Applications (15) 1402-1414
In the United States and several other countries, the development of population viability analyses (PVA) is a legal requirement of any species survival plan developed for threatened and endangered species. Despite the importance of pathogens in natural populations, little attention has been given to host-pathogen dynamics in PVA. To study...
Earthquake and ambient vibration monitoring of the steel-frame UCLA factor building
M.D. Kohler, P.M. Davis, E. Safak
2005, Earthquake Spectra (21) 715-736
Dynamic property measurements of the moment-resisting steel-frame University of California, Los Angeles, Factor building are being made to assess how forces are distributed over the building. Fourier amplitude spectra have been calculated from several intervals of ambient vibrations, a 24-hour period of strong winds, and from the 28 March 2003...
Simulation of reactive transport of injected CO2 on the Colorado Plateau, Utah, USA
S.P. White, R.G. Allis, Jeff Moore, T. Chidsey, C. Morgan, W. Gwynn, M. Adams
2005, Chemical Geology (217) 387-405
This paper investigates injection of CO2 into non-dome-shaped geological structures that do not provide the traps traditionally deemed necessary for the development of artificial CO2 reservoirs. We have developed a conceptual and two numerical models of the geology and groundwater along a cross-section lying approximately NW-SE and in the vicinity...
