Characterisation and modelling of washover fans
Chantal Donnelly, Asbury H. Sallenger Jr.
2007, Conference Paper, Coastal Sediments '07 - Proceedings of 6th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes
Pre- and post-storm topography and aerial photography, collected in regions where new washover fans were formed, were studied to determine the extent of morphologic, vegetative and anthropogenic control on washover shape and extent. When overwash is funnelled through a gap in a dune ridge and then spreads laterally on the...
Deglacial climate variability in central Florida, USA
Debra A. Willard, C.E. Bernhardt, G. R. Brooks, T. M. Cronin, T. Edgar, R. Larson
2007, Palaeogeography, Palaeoclimatology, Palaeoecology (251) 366-382
Pollen and ostracode evidence from lacustrine sediments underlying modern Tampa Bay, Florida, document frequent and abrupt climatic and hydrological events superimposed on deglacial warming in the subtropics. Radiocarbon chronology on well-preserved mollusk shells and pollen residue from core MD02-2579 documents continuous sedimentation in a variety of non-marine habitats in a...
Variation in northern bobwhite demography along two temporal scales
T.H. Folk, Randall R. Holmes, J. Barry Grand
2007, Population Ecology (49) 211-219
Quantification and understanding of demographic variation across intra- and inter-annual temporal scales can benefit from the development of theoretical models of evolution and applied conservation of species. We used long-term survey data for northern bobwhites (Colinus virginianus) collected at the northern and southern extent of its geographic range to develop...
A GIS-based groundwater travel time model to evaluate stream nitrate concentration reductions from land use change
K. E. Schilling, C.F. Wolter
2007, Environmental Geology (53) 433-443
Excessive nitrate-nitrogen (nitrate) loss from agricultural watersheds is an environmental concern. A common conservation practice to improve stream water quality is to retire vulnerable row croplands to grass. In this paper, a groundwater travel time model based on a geographic information system (GIS) analysis of readily available soil and topographic...
Differentiating pedogenesis from diagenesis in early terrestrial paleoweathering surfaces formed on granitic composition parent materials
S.G. Driese, L.G. Medaris Jr., M. Ren, Anthony C. Runkel, R.P. Langford
2007, Journal of Geology (115) 387-406
Unconformable surfaces separating Precambrian crystalline basement and overlying Proterozoic to Cambrian sedimentary rocks provide an exceptional opportunity to examine the role of primitive soil ecosystems in weathering and resultant formation of saprolite (weathered rock retaining rock structure) and regolith (weathered rock without rock structure), but many appear to have been...
Survival and tag retention of Pacific lamprey larvae and macrophthalmia marked with coded wire tags
M.H. Meeuwig, A.L. Puls, J.M. Bayer
2007, North American Journal of Fisheries Management (27) 96-102
We examined the survival, tag retention, and growth of Pacific lamprey Lampetra tridentata larvae and macrophthalmia marked with standard-length decimal coded wire tags and exposed to two levels of handling stress. The survival of marked individuals did not differ from that of unmarked individuals at either life stage for the...
Non-volcanic tremor driven by large transient shear stresses
J.L. Rubinstein, J.E. Vidale, J. Gomberg, P. Bodin, K. C. Creager, S. D. Malone
2007, Nature (448) 579-582
Non-impulsive seismic radiation or 'tremor' has long been observed at volcanoes and more recently around subduction zones. Although the number of observations of non-volcanic tremor is steadily increasing, the causative mechanism remains unclear. Some have attributed non-volcanic tremor to the movement of fluids, while its coincidence with geodetically observed slow-slip...
Microbial sulfate reduction and metal attenuation in pH 4 acid mine water
C.D. Church, R.T. Wilkin, Charles N. Alpers, R. O. Rye, R.B. Blaine
2007, Geochemical Transactions (8)
Sediments recovered from the flooded mine workings of the Penn Mine, a Cu-Zn mine abandoned since the early 1960s, were cultured for anaerobic bacteria over a range of pH (4.0 to 7.5). The molecular biology of sediments and cultures was studied to determine whether sulfate-reducing bacteria (SRB) were active in...
Effects of earlier sea ice breakup on survival and population size of polar bears in western Hudson Bay
E.V. Regehr, N.J. Lunn, Steven C. Amstrup, I. Stirling
2007, Journal of Wildlife Management (71) 2673-2683
Some of the most pronounced ecological responses to climatic warming are expected to occur in polar marine regions, where temperature increases have been the greatest and sea ice provides a sensitive mechanism by which climatic conditions affect sympagic (i.e., with ice) species. Population-level effects of climatic change, however, remain difficult...
Characterization of post-fire surface cover, soils, and burn severity at the Cerro Grande Fire, New Mexico, using hyperspectral and multispectral remote sensing
R.F. Kokaly, B.W. Rockwell, S.L. Haire, T. V. V. King
2007, Remote Sensing of Environment (106) 305-325
Forest fires leave behind a changed ecosystem with a patchwork of surface cover that includes ash, charred organic matter, soils and soil minerals, and dead, damaged, and living vegetation. The distributions of these materials affect post-fire processes of erosion, nutrient cycling, and vegetation regrowth. We analyzed high spatial resolution (2.4??m...
Comparative velocity structure of active Hawaiian volcanoes from 3-D onshore-offshore seismic tomography
J. Park, J.K. Morgan, C.A. Zelt, P. G. Okubo, L. Peters, N. Benesh
2007, Earth and Planetary Science Letters (259) 500-516
We present a 3-D P-wave velocity model of the combined subaerial and submarine portions of the southeastern part of the Island of Hawaii, based on first-arrival seismic tomography of marine airgun shots recorded by the onland seismic network. Our model shows that high-velocity materials (6.5-7.0??km/s) lie beneath Kilauea's summit, Koae...
Mars global digital dune database and initial science results
Rosalyn K. Hayward, Kevin F. Mullins, Lori K. Fenton, Trent M. Hare, Timothy N. Titus, Mary C. Bourke, Anthony Colaprete, Phillip R. Christensen
2007, Journal of Geophysical Research E: Planets (112)
A new Mars Global Digital Dune Database (MGD3) constructed using Thermal Emission Imaging System (THEMIS) infrared (IR) images provides a comprehensive and quantitative view of the geographic distribution of moderate‐ to large‐size dune fields (area >1 km2) that will help researchers to understand global climatic and sedimentary processes that have...
Direct and indirect estimates of natural mortality for Chesapeake Bay blue crab
D.A. Hewitt, D.M. Lambert, J.M. Hoenig, Romuald N. Lipcius, D.B. Bunnell, T.J. Miller
2007, Transactions of the American Fisheries Society (136) 1030-1040
Analyses of the population dynamics of blue crab Callinectes sapidus have been complicated by a lack of estimates of the instantaneous natural mortality rate (M). We developed the first direct estimates of M for this species by solving Baranov's catch equation for M given estimates of annual survival rate and exploitation rate. Annual survival rates were...
Local and regional factors affecting atmospheric mercury speciation at a remote location
H. Manolopoulos, J.J. Schauer, M.D. Purcell, T.M. Rudolph, Mark L. Olson, B. Rodger, David P. Krabbenhoft
2007, Journal of Environmental Engineering and Science (6) 491-501
Atmospheric concentrations of elemental (Hg0), reactive gaseous (RGM), and particulate (PHg) mercury were measured at two remote sites in the midwestern United States. Concurrent measurements of Hg0, PHg, and RGM obtained at Devil's Lake and Mt. Horeb, located approximately 65 km apart, showed that Hg0 and PHg concentrations were affected...
Estimating fishing mortality, natural mortality, and selectivity using recoveries from tagging young fish
H. Jiang, C. Brownie, J.E. Hightower, K. H. Pollock
2007, North American Journal of Fisheries Management (27) 773-781
Current methods for estimation of age- and year-specific instantaneous mortality rates based on multiyear, multiple-age tagging studies assume that it is feasible to tag fish in a wide range of ages. For some species, however, only the youngest one or two age-classes are readily available for tagging. Given the practical...
Modeling the movement of a pH perturbation and its impact on adsorbed zinc and phosphate in a wastewater‐contaminated aquifer
Douglas B. Kent, J.A. Wilkie, J.A. Davis
2007, Water Resources Research (43)
[1] Chemical conditions were perturbed in an aquifer with an ambient pH of 5.9 and wastewater-derived adsorbed zinc (Zn) and phosphate (P) contamination by injecting a pulse of amended groundwater. The injected groundwater had low concentrations of dissolved Zn and P, a pH value of...
On the choice of statistical models for estimating occurrence and extinction from animal surveys
R.M. Dorazio
2007, Ecology (88) 2773-2782
In surveys of natural animal populations the number of animals that are present and available to be detected at a sample location is often low, resulting in few or no detections. Low detection frequencies are especially common in surveys of imperiled species; however, the choice of sampling method and protocol...
Alternative community structures in a kelp-urchin community: A qualitative modeling approach
G. Montano-Moctezuma, H.W. Li, P.A. Rossignol
2007, Ecological Modelling (205) 343-354
Shifts in interaction patterns within a community may result from periodic disturbances and climate. The question arises as to the extent and significance of these shifting patterns. Using a novel approach to link qualitative mathematical models and field data, namely using the inverse matrix to identify the community matrix, we...
Crustal structure of Wrangellia and adjacent terranes inferred from geophysical studies along a transect through the northern Talkeetna Mountains
J.M.G. Glen, J. Schmidt, L. Pellerin, D.K. McPhee, J.M. O’Neill
2007, Special Paper of the Geological Society of America 21-41
Recent investigations of the Talkeetna Mountains in south-central Alaska were undertaken to study the region's framework geophysics and to reinterpret structures and crustal composition. Potential field (gravity and magnetic) and magnetotelluric (MT) data were collected along northwest-trending profiles as part of the U.S. Geological Survey's Talkeetna Mountains transect project. The...
Distributions of pharmaceuticals in an urban estuary during both dry- and wet-weather conditions
M.J. Benotti, Bruce J. Brownawell
2007, Environmental Science & Technology (41) 5795-5802
Pharmaceuticals and selected major human metabolites are ubiquitous in Jamaica Bay, a wastewater-impacted estuary at concentrations in the low ng/L to low ??g/L range. Concentrations throughout the bay are often consistent with conservative behavior during dry-weather conditions, as evidenced by nearly linear concentration-salinity relationships. Deviation from conservative behavior is noted...
Distribution and sedimentary characteristics of tsunami deposits along the Cascadia margin of western North America
R. Peters, B. Jaffe, G. Gelfenbaum
2007, Sedimentary Geology (200) 372-386
Tsunami deposits have been found at more than 60 sites along the Cascadia margin of Western North America, and here we review and synthesize their distribution and sedimentary characteristics based on the published record. Cascadia tsunami deposits are best preserved, and most...
The effects of acidic mine drainage from historical mines in the Animas River watershed, San Juan County, Colorado—What is being done and what can be done to improve water quality?
Stanley E. Church, Robert J. Owen, Paul Von Guerard, Philip L. Verplanck, Briant A. Kimball, Douglas B. Yager
2007, Book chapter, Understanding and responding to hazardous substances at mine sites in the western United States
Historical production of metals in the western United States has left a legacy of acidic drainage and toxic metals in many mountain watersheds that are a potential threat to human and ecosystem health. Studies of the effects of historical mining on surface water chemistry and riparian habitat in the Animas...
Evidence for a physical linkage between galactic cosmic rays and regional climate time series
C. A. Perry
2007, Advances in Space Research (40) 353-364
The effects of solar variability on regional climate time series were examined using a sequence of physical connections between total solar irradiance (TSI) modulated by galactic cosmic rays (GCRs), and ocean and atmospheric patterns that affect precipitation and streamflow. The solar energy reaching the Earth's surface and its oceans is...
Penokean tectonics along a promontory-embayment margin in east-central Minnesota
V.W. Chandler, Terrence Boerboom, M.A. Jirsa
2007, Precambrian Research (157) 26-49
Recent geologic investigations in east-central Minnesota have utilized geophysical data, test drilling, and high-resolution geochronologic dating to produce a significantly improved map of a poorly exposed part of the 1880-1830 Ma Penokean orogen. These investigations have elucidated major changes in the structure of the orogen, as compared to its counterparts...
Physically based estimation of soil water retention from textural data: General framework, new models, and streamlined existing models
John R. Nimmo, William N. Herkelrath, Luna Laguna
2007, Vadose Zone Journal (6) 766-773
Numerous models are in widespread use for the estimation of soil water retention from more easily measured textural data. Improved models are needed for better prediction and wider applicability. We developed a basic framework from which new and existing models can be derived to facilitate improvements. Starting from the assumption...
