Publications
Filter Total Items: 818
Evaluation of management efforts to reduce nutrient and sediment contributions to the Chesapeake Bay estuary
No abstract available.
Authors
Z. Easton, K. Stephenson, B. Benham, John K. Böhlke, A. Buda, A. Collick, L. Fowler, E. Gilinsky, C. Hershner, Andrew Miller, Gregory B. Noe, L. Palm-Forster, T. Thompson
Achieving water quality goals in the Chesapeake Bay: A comprehensive evaluation of system response
A Comprehensive Evaluation of System ResponseAchieving Water Quality Goals in the Chesapeake Bay: A Comprehensive Evaluation of System Response (CESR) includes an evaluation of why progress toward meeting the TMDL and water quality standards has been slower than expected and offers options for how progress can be accelerated. This report is a summation of a three year investigation into the 40 yea
Exploring the influence of input feature space on CNN-based geomorphic feature extraction from digital terrain data
Many studies of Earth surface processes and landscape evolution rely on having accurate and extensive data sets of surficial geologic units and landforms. Automated extraction of geomorphic features using deep learning provides an objective way to consistently map landforms over large spatial extents. However, there is no consensus on the optimal input feature space for such analyses. We explore t
Authors
Aaron E. Maxwell, William Elijah Odom, Charles M. Shobe, Daniel H. Doctor, Michelle S. Bester, Tobi Ore
Rapid estimation of minimum depth-to-bedrock from lidar leveraging deep-learning-derived surficial material maps
Previously glaciated landscapes often share similar surficial characteristics, including large areas of exposed bedrock, blankets of till deposits, and alluvium-floored valleys. These materials play significant roles in geologic and hydrologic resources, geohazards, and landscape evolution; however, the vast extents of many previously glaciated landscapes have rendered comprehensive, detailed fiel
Authors
William Elijah Odom, Daniel H. Doctor
Multi-proxy record of ocean-climate variability during the last 2 millennia on the Mackenzie Shelf, Beaufort Sea
A 2,000 year-long oceanographic history, in sub-centennial resolution, from a Canadian Beaufort Sea continental shelf site (60meters water depth) near the Mackenzie River outlet is reconstructed from ostracode and foraminifera faunal assemblages, shell stable isotopes (delta 18O, delta 13C) and sediment biogenic silica. The chronology of three sediment cores making up the composite section was es
Authors
Laura Gemery, Thomas M. Cronin, Lee W. Cooper, Lucy Roberts, Lloyd D Keigwin, Jason A. Addison, Melanie Leng, Peigen Lin, Cedric Magen, Marci E. Marot, Valerie Schwartz
Unzipping supercontinent Pangea: Geologic, potential field data, and buried structures, and a case for sequential Atlantic opening
Amalgamation of Pangea culminated with zippered N-to-S closing of the Theic ocean during the Alleghanian orogeny. Transpressional-rotational collision produced widespread dextral faulting throughout the eastern Appalachian hinterland, and thrust faulting in the western hinterland and foreland. The partially buried southern Appalachian Eastern Piedmont fault system is a product of late Paleozoic tr
Authors
Aaron G. Stubblefield, Robert D. Jr. Hatcher, J. Wright Horton,, David L. Daniels
Investigating geomorphic change using a structure from motion elevation model created from historical aerial imagery: A case study in northern Lake Michigan, USA
South Manitou Island, part of Sleeping Bear Dunes National Lakeshore in northern Lake Michigan, is a post-glacial lacustrine landscape with substantial geomorphic changes including landslides, shoreline and bluff retreat, and sand dune movement. These changes involve interrelated processes, and are influenced to different extents by lake level, climate change, and land use patterns, among other fa
Authors
Jessica D. DeWitt, Francis Ashland
Redefinition of the Petersburg batholith and implications for crustal inheritance in the Dinwiddie terrane, Virginia, USA
Field relations as well as geochemical and petrologic studies of metaigneous rocks assigned to the Pennsylvanian–Permian Petersburg batholith identify at least two distinct rock types: foliated metagranitoid gneiss and massive to porphyritic granite. Foliated metagranitoid gneiss of mostly granodioritic composition is geochemically distinct from associated massive and porphyritic granitic rocks. T
Authors
Mark W. Carter, Ryan J. McAleer, Christopher Holm-Denoma, Marcie E. Occhi, Brent E. Owens, Jorge A. Vazquez
Sediment and nutrient deposition over a reconnected floodplain during large-scale river diversions, the Bonnet Carré spillway in 2011, 2016, and 2019
In hopes of reversing or slowing the decline of the river delta, water diversions have been built and planned, and natural diversions have formed and been allowed to develop along the lower Mississippi River. In addition to the possibility of building land, these diversions allow for the storage of nutrients within the deposited sediments and provide a buffer from coastal storm surge flooding. Dep
Authors
Daniel Kroes, Gregory B. Noe, David Ramirez, Brian Vosburg
The stratigraphy and stratigraphic nomenclature of the Goochland Terrane in the Piedmont Province of east-central Virginia
The Goochland terrane is a structurally isolated crustal block in the eastern Piedmont of Virginia. It is composed of the previously named State Farm Gneiss, Montpelier Anorthosite, Sabot Amphibolite, and Maidens Gneiss, but also includes the Scotchtown Gneiss, Teman Gneiss, and Old Bandana Gneiss which are formally named and defined herein. The eastern part of the Goochland terrane is antiformal
Authors
Robert E. Weems, Eleanora I. Robbins
Planktic foraminifera
Planktic foraminifera are single-celled marine organisms that secrete calcium carbonate tests. They live in the ocean's photic zone, and when they die, their tests, each about the size of a grain of sand, collect on the ocean floor. The geographic distribution of planktic foraminifera is mostly governed by the temperature and salinity of the ocean surface, and species assemblages are generally arr
Authors
Harry J. Dowsett, Marci M. Robinson
Holocene vegetation dynamics of circum-Arctic permafrost peatlands
Vegetation shifts in circum-Arctic permafrost peatlands drive feedbacks with important consequences for peatland carbon budgets and the extent of permafrost thaw under changing climate. Recent shrub expansion across Arctic tundra environments has led to an increase in above-ground biomass, but the long-term spatiotemporal dynamics of shrub and tree growth in circum-Arctic peatlands remain unquanti
Authors
Richard Fewster, Paul J. Morris, Graeme T. Swindles, Ruza F. Ivanovic, Claire C. Treat, Miriam C. Jones