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Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
Laurentian Great Lakes Phytoplankton And Their Water Quality Characteristics, Including A Diatom-Based Model For Paleoreconstruction Of Phosphorus, Euan D. Reavie, Adam J. Heathcote, Victoria L. Shaw Chraïbi
Laurentian Great Lakes Phytoplankton And Their Water Quality Characteristics, Including A Diatom-Based Model For Paleoreconstruction Of Phosphorus, Euan D. Reavie, Adam J. Heathcote, Victoria L. Shaw Chraïbi
Department of Earth and Atmospheric Sciences: Faculty Publications
Recent shifts in water quality and food web characteristics driven by anthropogenic impacts on the Laurentian Great Lakes warranted an examination of pelagic primary producers as tracers of environmental change. The distributions of the 263 common phytoplankton taxa were related to water quality variables to determine taxon-specific responses that may be useful in indicator models. A detailed checklist of taxa and their environmental optima are provided. Multivariate analyses indicated a strong relationship between total phosphorus (TP) and patterns in the diatom assemblages across the Great Lakes. Of the 118 common diatom taxa, 90 (76%) had a directional response along the …
Vadose Zone Lag Time And Potential 21st Century Climate Change Effects On Spatially Distributed Groundwater Recharge In The Semi-Arid Nebraska Sand Hills, N. R. Rossman, Vitaly A. Zlotnik, Clinton Rowe, Jozsef Szilagyi
Vadose Zone Lag Time And Potential 21st Century Climate Change Effects On Spatially Distributed Groundwater Recharge In The Semi-Arid Nebraska Sand Hills, N. R. Rossman, Vitaly A. Zlotnik, Clinton Rowe, Jozsef Szilagyi
Department of Earth and Atmospheric Sciences: Faculty Publications
Deep drainage of water below plant root zones (potential groundwater recharge) will become groundwater recharge (GR) after a delay (or lag time) in which soil moisture traverses the vadose zone before reaching the water table. Depending on the thickness of the vadose zone, the magnitude of deep drainage, and soil hydraulic properties, lag times will vary broadly, exceeding decades to centuries in semi-arid and arid environments. Yet, studies of future climate change impacts to GR have typically avoided focusing on impacts beyond 100 years and often neglect to consider lag effects caused by the vadose zone. We investigate the effects …
Architecture, Heterogeneity, And Origin Of Late Miocene Fluvial Deposits Hosting The Most Important Aquifer In The Great Plains, Usa, R. Matthew Joeckel, Steve R. Wooden Jr., Jesse T. Korus, Jon Garbisch
Architecture, Heterogeneity, And Origin Of Late Miocene Fluvial Deposits Hosting The Most Important Aquifer In The Great Plains, Usa, R. Matthew Joeckel, Steve R. Wooden Jr., Jesse T. Korus, Jon Garbisch
Department of Earth and Atmospheric Sciences: Faculty Publications
The Ash Hollow Formation (AHF) of the Ogallala Group is an important sedimentary archive of the emergence of the Great Plains and it contains major groundwater resources. Stratal patterns of constituent alluvial lithofacies demonstrate that the AHF is much more heterogeneous than is commonly assumed. Very fine- to fine-grained sandstone dominate overall, chiefly lithofacies Sm (massive to locally stratified sandstone). Stacked, thin sheets of Sm with accretionary macroform surfaces are common, indicating that many sandstone architectural elements originated as compound-bar deposits in dominantly sand-bed streams. Channel forms are difficult to identify and steep cutbanks are absent. Multiple units of lithofacies …
Dune Formation On Late Holocene Sandy Bay Barriers Along Lake Michigan’S Door Peninsula: The Importance Of Increased Sediment Supply Following The Nipissing And Algoma High Lake-Level Phases, J. Elmo Rawling Iii, Paul R. Hanson
Dune Formation On Late Holocene Sandy Bay Barriers Along Lake Michigan’S Door Peninsula: The Importance Of Increased Sediment Supply Following The Nipissing And Algoma High Lake-Level Phases, J. Elmo Rawling Iii, Paul R. Hanson
Department of Earth and Atmospheric Sciences: Faculty Publications
This study focuses on the geomorphology and geochronology of dunes formed on three sandy barrier systems at Clark, Europe and Kangaroo Lakes in Wisconsin’s Door Peninsula. The Lake Michigan shoreline in the peninsula contains abundant evidence for fluctuations in lake level with paleo-shoreline features that lie up to ~7 m above the present shoreline. Dunes are not very common along the Lake Michigan shoreline in Wisconsin, but the three bay barriers studied contain beach ridges that were buried by varying depths of eolian sand in the form of low relief sandsheets as well as parabolic and transverse dunes that have …
Coastal Geology And Recent Origins For Sand Point, Lake Superior, Timothy G. Fisher, David E. Krantz, Mario R. Castaneda, Walter L. Loope, Harry M. Jol, Ronald J. Goble, Melinda C. Higley, Samantha Dewald, Paul R. Hanson
Coastal Geology And Recent Origins For Sand Point, Lake Superior, Timothy G. Fisher, David E. Krantz, Mario R. Castaneda, Walter L. Loope, Harry M. Jol, Ronald J. Goble, Melinda C. Higley, Samantha Dewald, Paul R. Hanson
Department of Earth and Atmospheric Sciences: Faculty Publications
Sand Point is a small cuspate foreland located along the southeastern shore of Lake Superior within Pictured Rocks National Lakeshore near Munising, Michigan. Park managers’ concerns for the integrity of historic buildings at the northern periphery of the point during the rising lake levels in the mid-1980s greatly elevated the priority of research into the geomorphic history and age of Sand Point. To pursue this priority, we recovered sediment cores from four ponds on Sand Point, assessed subsurface stratigraphy onshore and offshore using geophysical techniques, and interpreted the chronology of events using radiocarbon and luminescence dating. Sand Point formed at …