Publications
These publications showcase the significant science conducted in our Science Centers.
Filter Total Items: 16782
Environmental factors that influence the location of crop agriculture in the conterminous United States
This report presents and describes high-resolution geospatial data identifying the range of environmental conditions that influence the location of cropped agricultural lands in the conterminous United States. Also presented are estimates of the extent of land where environmental constraints limit agricultural production (marginal land) and the extents of land where modifications overcome environm
Authors
Nancy T. Baker, Paul D. Capel
Assessing hypotheses about nesting site occupancy dynamics
Hypotheses about habitat selection developed in the evolutionary ecology framework assume that individuals, under some conditions, select breeding habitat based on expected fitness in different habitat. The relationship between habitat quality and fitness may be reflected by breeding success of individuals, which may in turn be used to assess habitat quality. Habitat quality may also be assessed v
Authors
Florent Bled, J. Andrew Royle, Emmanuelle Cam
Detailed sections from auger holes in the Elizabethtown 1:100,000-scale quadrangle, North Carolina
The Elizabethtown 1:100,000 quadrangle is in the west-central part of the Coastal Plain of southeastern North Carolina. The Coastal Plain, in this region, consists mostly of unlithified sediments that range in age from Late Cretaceous to Holocene. These sediments lie with profound unconformity on complexly deformed metamorphic and igneous rocks similar to rocks found immediately to the west in the
Authors
Robert E. Weems, William C. Lewis, Joseph H. Murray, David B. Queen, Jeffrey B. Grey, Benjamin D. DeJong
Surficial geologic map of the Elizabethtown 30' x 60' quadrangle, North Carolina
The Elizabethtown 30' x 60' quadrangle is located in southeastern North Carolina between Fayetteville and Wilmington. Most of the area is flat to gently rolling, although steep slopes occur locally along some of the larger streams. Total relief in the area is slightly over 210 feet (ft), with elevations ranging from slightly less than 10 ft above sea level along the Black River (east of Rowan in t
Authors
Robert E. Weems, William C. Lewis, E. Allen Crider
Anthropocene streams and base-level controls from historic dams in the unglaciated mid-Atlantic region, USA
Recently, widespread valley-bottom damming for water power was identified as a primary control on valley sedimentation in the mid-Atlantic US during the late seventeenth to early twentieth century. The timing of damming coincided with that of accelerated upland erosion during post-European settlement land-use change. In this paper, we examine the impact of local drops in base level on incision int
Authors
Dorothy Merritts, Robert Walter, Michael Rahnis, Jeff Hartranft, Scott Cox, Allen Gellis, Noel Potter, William Hilgartner, Michael J. Langland, Lauren Manion, Caitlin Lippincott, Sauleh Siddiqui, Zain Rehman, Chris Scheid, Laura Kratz, Andrea Shilling, Matthew Jenschke, Katherine Datin, Elizabeth Cranmer, Austin Reed, Derek Matuszewski, Mark Voli, Erik Ohlson, Ali Neugebauer, Aakash Ahamed, Conor Neal, Allison Winter, Steven Becker
Whole-rock and sulfide-mineral geochemical data for samples from volcanogenic massive sulfide deposits of the Bonnifield district, east-central Alaska
This Open-File Report presents geochemical data for outcrop and drill-core samples from volcanogenic massive sulfide deposits and associated metaigneous and metasedimentary rocks in the Wood River area of the Bonnifield mining district, northern Alaska Range, east-central Alaska. The data consist of major- and trace-element whole-rock geochemical analyses, and major- and trace-element analyses of
Authors
Cynthia Dusel-Bacon, John F. Slack, Alan E. Koenig, Nora K. Foley, Robert L. Oscarson, Kathleen D. Gans
An adaptive-management framework for optimal control of hiking near golden eagle nests in Denali National Park
Unintended effects of recreational activities in protected areas are of growing concern. We used an adaptive-management framework to develop guidelines for optimally managing hiking activities to maintain desired levels of territory occupancy and reproductive success of Golden Eagles (Aquila chrysaetos) in Denali National Park (Alaska, U.S.A.). The management decision was to restrict human access
Authors
Julien Martin, Paul L. Fackler, James D. Nichols, Michael C. Runge, Carol L. McIntyre, Bruce L. Lubow, Maggie C. McCluskie, Joel A. Schmutz
Global biodiversity: Indicators of recent declines
In 2002, world leaders committed, through the Convention on Biological Diversity, to achieve a significant reduction in the rate of biodiversity loss by 2010. We compiled 31 indicators to report on progress toward this target. Most indicators of the state of biodiversity (covering species’ population trends, extinction risk, habitat extent and condition, and community composition) showed declines,
Authors
Stuart H.M. Butchart, Matt Walpole, Ben Collen, Arco Van Strien, Jorn P.W. Scharlemann, Rosamunde E.A. Almond, Jonathan E.M. Baillie, Bastian Bomhard, Claire Brown, John Bruno, Kent E. Carpenter, Genevieve M. Carr, Janice Chanson, Anna M. Chenery, Jorge Csirke, Nick C. Davidson, Frank Dentener, Matt Foster, Alessandro Galli, James N. Galloway, Piero Genovesi, Richard D. Gregory, Marc Hockings, Valerie Kapos, Jean-Francois Lamarque, Fiona Leverington, Jonathan Loh, Melodie A. McGeoch, Louise McRae, Anahit Minasyan, Monica Hernandez Morcillo, Thomasina E.E. Oldfield, Daniel Pauly, Suhel Quader, Carmen Revenga, John R. Sauer, Benjamin Skolnik, Dian Spear, Damon Stanwell-Smith, Simon N. Stuart, Andy Symes, Megan Tierney, Tristan D. Tyrrell, Jean-Christophe Vie, Reg Watson
Pockmarks: Self-scouring seep features?
Pockmarks, or seafloor craters, occur worldwide in a variety of geologic settings and are often associated with fluid discharge. The mechanisms responsible for pockmark preservation, and pockmarks? relation to active methane venting are not well constrained. Simple numerical simulations run in 2-and 3-dimensions, and corroborated by flume tank experiments, indicate turbulence may play a role in po
Authors
Laura L. Brothers, Joseph T. Kelley, Daniel F. Belknap, Walter A. Barnhardt, Peter O. Koons
Laboratory formation of non-cementing, methane hydrate-bearing sands
Naturally occurring hydrate-bearing sands often behave as though methane hydrate is acting as a load-bearing member of the sediment. Mimicking this behavior in laboratory samples with methane hydrate likely requires forming hydrate from methane dissolved in water. To hasten this formation process, we initially form hydrate in a free-gas-limited system, then form additional hydrate by circulating m
Authors
William F. Waite, Peter M. Bratton, David H. Mason
Evidence and biogeochemical implications for glacially-derived sediments in an active margin cold seep
Delineating sediment organic matter origins and sediment accumulation rates at gas hydratebearing and hydrocarbon seeps is complicated by the microbial transfer of 13C-depleted and 14Cdepleted methane carbon into sedimentary pools. Sediment 13C and 14C measurements from four cores recovered at Bullseye vent on the northern Cascadia margin are used to identify methane carbon assimilation into diffe
Authors
John W. Pohlman, Michael Riedel, Ivana Novosel, James E. Bauer, Elizabeth A. Canuel, Charles K. Paull, Richard B. Coffin, Kenneth S. Grabowski, David L. Knies, Roy D. Hyndman, George D. Spence
Inter-laboratory comparison of wave velocity measures.
This paper presents an eight-laboratory comparison of compressional and shear wave velocities measured in F110 Ottawa sand. The study was run to quantify the physical property variations one should expect in heterogeneous, multiphase porous materials by separately quantifying the variability inherent in the measurement techniques themselves. Comparative tests were run in which the sand was dry, w
Authors
William F. Waite, J.C. Santamarina, M. Rydzy, S.H. Chong, J.L.H. Grozic, K. Hester, J. Howard, T.J. Kneafsey, J.Y. Lee, S. Nakagawa, J. Priest, E. Reese, H. Koh, E. D. Sloan, A. Sultaniya