Thermal maturity patterns in the Ordovician and Devonian of Pennsylvania using conodont color alteration index (CAI) and vitrinite reflectance (%Ro)
J.E. Repetski, R. T. Ryder, J.A. Harper, M.H. Trippi
2006, Northeastern Geology and Environmental Sciences (28) 266-294
This new series of maps enhances previous thermal maturity maps in Pennsylvania by establishing: 1) new subsurface CAI data points for the Ordovician and Devonian and 2) new %Ro and Rock Eval subsurface data points for Middle and Upper Devonian black shale units. Thermal maturity values for the Ordovician and...
Precessional forcing of lacustrine sedimentation in the late Cenozoic Chemeron Basin, Central Kenya Rift, and calibration of the Gauss/Matuyama boundary
A.L. Deino, J.D. Kingston, J. M. Glen, R.K. Edgar, A. Hill
2006, Earth and Planetary Science Letters (247) 41-60
The fluviolacustrine sedimentary sequence of the Chemeron Formation exposed in the Barsemoi River drainage, Tugen Hills, Kenya, contains a package of five successive diatomite/fluvial cycles that record the periodic development of freshwater lakes within the axial portion of the Central Kenya Rift. The overwhelming abundance in the diatomite of planktonic...
Genetic structure of natural and restored shoalgrass Halodule wrightii populations in the NW Gulf of Mexico
S.E. Travis, P. Sheridan
2006, Marine Ecology Progress Series (322) 117-127
The decline of seagrass communities worldwide has sparked an urgent need for effective restoration strategies, which require a working knowledge of population genetic structure. Halodule wrighti is a common seagrass of the Caribbean region that is being restored to areas of the Gulf of Mexico, yet little is known of...
Optimization strategies for sediment reduction practices on roads in steep, forested terrain
Mary Ann Madej, E.A. Eschenbach, C. Diaz, R. Teasley, K. Baker
2006, Earth Surface Processes and Landforms (31) 1643-1656
Many forested steeplands in the western United States display a legacy of disturbances due to timber harvest, mining or wildfires, for example. Such disturbances have caused accelerated hillslope erosion, leading to increased sedimentation in fish-bearing streams. Several restoration techniques have been implemented to address these problems in mountain catchments, many...
Diatom diversity in chronically versus episodically acidified adirondack streams
S.I. Passy, I. Ciugulea, G.B. Lawrence
2006, International Review of Hydrobiology (91) 594-608
The relationship between algal species richness and diversity, and pH is controversial. Furthermore, it is still unknown how episodic stream acidification following atmospheric deposition affects species richness and diversity. Here we analyzed water chemistry and diatom epiphyton dynamics and showed their contrasting behavior in chronically vs. episodically acidic streams in...
Using self-organizing maps to determine observation threshold limit predictions in highly variant data
C.A. Paganoni, K.C. Chang, M. B. Robblee
2006, Conference Paper, Proceedings of SPIE - The International Society for Optical Engineering
A significant data quality challenge for highly variant systems surrounds the limited ability to quantify operationally reasonable limits on the data elements being collected and provide reasonable threshold predictions. In many instances, the number of influences that drive a resulting value or operational range is too large to enable physical...
Spatio-temporal availability of soft mast in clearcuts in the Southern Appalachians
M. J. Reynolds-Hogland, M.S. Mitchell, R. A. Powell
2006, Forest Ecology and Management (237) 103-114
Soft mast is an important resource for many wild populations in the Southern Appalachians, yet the way clear-cutting affects availability of soft mast though time is not fully understood. We tested a theoretical model of temporal availability of soft mast in clearcuts using empirical data on percent cover and berry...
CO2 and CH4 exchanges between land ecosystems and the atmosphere in northern high latitudes over the 21st century
Q. Zhuang, J. M. Melillo, M.C. Sarofim, D. W. Kicklighter, A. D. McGuire, B.S. Felzer, A. Sokolov, R.G. Prinn, P.A. Steudler, S. Hu
2006, Geophysical Research Letters (33)
Terrestrial ecosystems of the northern high latitudes (above 50??N) exchange large amounts of CO2 and CH4 with the atmosphere each year. Here we use a process-based model to estimate the budget of CO 2 and CH4 of the region for current climate conditions and for future scenarios by considering effects...
Migration depths of juvenile Chinook salmon and steelhead relative to total dissolved gas supersaturation in a Columbia River reservoir
J.W. Beeman, A.G. Maule
2006, Transactions of the American Fisheries Society (135) 584-594
The in situ depths of juvenile salmonids Oncorhynchus spp. were studied to determine whether hydrostatic compensation was sufficient to protect them from gas bubble disease (GBD) during exposure to total dissolved gas (TDG) supersaturation from a regional program of spill at dams meant to improve salmonid passage survival. Yearling Chinook...
Quantifying surface water–groundwater interactions using time series analysis of streambed thermal records: Method development
Christine E Hatch, Andrew T. Fisher, Justin S. Revenaugh, Jim Constantz, Chris Ruehl
2006, Water Resources Research (42)
We present a method for determining streambed seepage rates using time series thermal data. The new method is based on quantifying changes in phase and amplitude of temperature variations between pairs of subsurface sensors. For a reasonable range of streambed thermal properties and sensor spacings the time series method should...
Instantaneous unit hydrograph evaluation for rainfall-runoff modeling of small watersheds in North and South Central Texas
T.G. Cleveland, X. He, W.H. Asquith, X. Fang, D.B. Thompson
2006, Journal of Irrigation and Drainage Engineering (132) 479-485
Data from over 1,600 storms at 91 stations in Texas are analyzed to evaluate an instantaneous unit hydrograph (IUH) model for rainfall-runoff models. The model is fit to observed data using two different merit functions: a sum of squared errors function, and an absolute error at the peak discharge time...
Incorporation of seawater into mid-ocean ridge lava flows during emplacement
S.A. Soule, D.J. Fornari, M.R. Perfit, W.I. Ridley, M.H. Reed, J.R. Cann
2006, Earth and Planetary Science Letters (252) 289-307
Evidence for the interaction between seawater and lava during emplacement on the deep seafloor can be observed in solidified flows at a variety of scales including rapid quenching of their outer crusts and the formation of lava pillars through the body of the flow. Recently, an additional interaction, incorporation of...
Cross-calibration of A.M. constellation sensors for long term monitoring of land surface processes
D. Meyer, G. Chander
2006, Conference Paper, Proceedings of SPIE - The International Society for Optical Engineering
Data from multiple sensors must be used together to gain a more complete understanding of land surface processes at a variety of scales. Although higher-level products derived from different sensors (e.g., vegetation cover, albedo, surface temperature) can be validated independently, the degree to which these sensors and their products can...
Size distribution of submarine landslides and its implication to tsunami hazard in Puerto Rico
Uri S. ten Brink, E.L. Geist, B.D. Andrews
2006, Geophysical Research Letters (33) 1-4
We have established for the first time a size frequency distribution for carbonate submarine slope failures. Using detailed bathymetry along the northern edge of the carbonate platform north of Puerto Rico, we show that the cumulative distribution of slope failure volumes follows a power-law distribution. The power-law exponent of this...
A volcano bursting at the seams: Inflation, faulting, and eruption at Sierra Negra volcano, Galápagos
William W. Chadwick, Dennis J. Geist, Sigurjon Jonsson, Michael P. Poland, Daniel J. Johnson, Charles M. Meertens
2006, Geology (34) 1025-1028
The results of geodetic monitoring since 2002 at Sierra Negra volcano in the Galápagos Islands show that the filling and pressurization of an ∼2-km-deep sill eventually led to an eruption that began on 22 October 2005. Continuous global positioning system (CGPS) monitoring measured >2 m of accelerating inflation leading up...
Wave energy dissipation by intertidal sand waves on a mixed-sediment Beach
P. Adams, P. Ruggiero
2006, Conference Paper, Coastal Dynamics 2005 - Proceedings of the Fifth Coastal Dynamics International Conference
Within the surf zone, the energy expended by wave breaking is strongly influenced by nearshore bathymetry, which is often linked to the character and abundance of local sediments. Based upon a continuous, two year record of Argus Beach Monitoring System (ABMS) data on the north shore of Kachemak Bay in...
Measuring permanence of CO2 storage in saline formations: The Frio experiment
Susan D. Hovorka, Sally M. Benson, Christine Doughty, Barry M. Freifeild, Shinichi Sakurai, Thomas M. Daley, Yousif K. Kharaka, Mark H. Holtz, Robert C. Trautz, H. Seay Nance, Larry R. Myer, Kevin G. Knauss
2006, Environmental Geosciences (13) 105-121
If CO2 released from fossil fuel during energy production is returned to the subsurface, will it be retained for periods of time significant enough to benefit the atmosphere? Can trapping be assured in saline formations where there is no history of hydrocarbon accumulation? The Frio experiment in Texas was...
Developing a bubble number-density paleoclimatic indicator for glacier ice
M. K. Spencer, R. B. Alley, J. J. Fitzpatrick
2006, Journal of Glaciology (52) 358-364
Past accumulation rate can be estimated from the measured number-density of bubbles in an ice core and the reconstructed paleotemperature, using a new technique. Density increase and grain growth in polar firn are both controlled by temperature and accumulation rate, and the integrated effects are recorded in the number-density of...
Status and trends in demography of northern spotted owls, 1985-2003
R.G. Anthony, E.D. Forsman, A.B. Franklin, David R. Anderson, K.P. Burnham, Gary C. White, C.J. Schwarz, J.D. Nichols, J.E. Hines, G.S. Olson, S.H. Ackers, L.S. Andrews, B.L. Biswell, P.C. Carlson, L.V. Diller, K.M. Dugger, K.E. Fehring, T.L. Fleming, R.P. Gerhardt, S.A. Gremel, R. J. Gutierrez, P.J. Happe, D.R. Herter, J.M. Higley, R.B. Horn, L.L. Irwin, P.J. Loschl, J.A. Reid, S.G. Sovern
P.R. Krausman, editor(s)
2006, Wildlife Monographs 1-48
We analyzed demographic data from northern spotted owls (Strix occidentalis caurina) from 14 study areas in Washington, Oregon, and California for 1985-2003. The purpose of our analyses was to provide an assessment of the status and trends of northern spotted owl populations throughout most of their geographic range. The 14...
Proximate and landscape factors influence grassland bird distributions
M.A. Cunningham, Douglas H. Johnson
2006, Ecological Applications (16) 1062-1075
Ecologists increasingly recognize that birds can respond to features well beyond their normal areas of activity, but little is known about the relative importance of landscapes and proximate factors or about the scales of landscapes that influence bird distributions. We examined the influences of tree cover at both proximate and...
Flow-specific trends in river-water quality resulting from the effects of the clean air act in three mesoscale, forested river basins in the northeastern United States through 2002
Peter S. Murdoch, J. B. Shanley
2006, Environmental Monitoring and Assessment (120) 1-25
Two new methods for assessing temporal trends in stream-solute concentrations at specific streamflow ranges were applied to long (40 to 50-year) but sparse (bi-weekly to quarterly sampling) stream-water quality data collected at three forested mesoscale basins along an atmospheric deposition gradient in the northeastern United States (one in north-central Pennsylvania,...
Fire severity and plant age in postfire resprouting of woody plants in sage scrub and chaparral
Jon E. Keeley
2006, Madroño (53) 373-379
Postfire resprouting by woody plants confers a marked advantage in rate of recovery over species that regenerate entirely from seed. However, the predictability of this advantage varies markedly between species, with some showing nearly 100% rootcrown survival and others often much lower. This study examined patterns of fire-caused mortality and...
Form drag in rivers due to small-scale natural topographic features: 2. Irregular sequences
J. W. Kean, J.D. Smith
2006, Journal of Geophysical Research F: Earth Surface (111)
The size, shape, and spacing of small-scale topographic features found on the boundaries of natural streams, rivers, and floodplains can be quite variable. Consequently, a procedure for determining the form drag on irregular sequences of different-sized topographic features is essential for calculating near-boundary flows and sediment transport. A method for...
Tree mortality from fire and bark beetles following early and late season prescribed fires in a Sierra Nevada mixed-conifer forest
Dylan W. Schwilk, Eric E. Knapp, Scott Ferrenberg, Jon E. Keeley, Anthony C. Caprio
2006, Forest Ecology and Management (232) 36-45
Over the last century, fire exclusion in the forests of the Sierra Nevada has allowed surface fuels to accumulate and has led to increased tree density. Stand composition has also been altered as shade tolerant tree species crowd out shade intolerant species. To restore forest structure and reduce the risk...
Size dimorphism, molt status, and body mass variation of Prairie Falcons nesting in the Snake River Birds of Prey National Conservation Area
Karen Steenhof, James O. McKinley
2006, Journal of Raptor Research (40) 71-75
Birds face challenges in how they allocate energy during the reproductive season. Most temperate zone species do not breed and molt at the same time, presumably because of the high energy demands of these two activities (Espie et al. 1996 and citations therein). However, representatives of at least four raptor...
