Assessing The Habitability Of Mars Using Impact Crater Statistics, 2019 University of Tennessee, Knoxville
Assessing The Habitability Of Mars Using Impact Crater Statistics, Emily N. Shaver
EURēCA: Exhibition of Undergraduate Research and Creative Achievement
Because Mars lacks a global magnetic field or protective ozone layer, its surface is unshielded to harsh radiation from space. This ionizing radiation breaks down any organic components in the soil at the martian surface on timescales of tens to hundreds of millions years (10–100 Ma). In planetary geology, we use the density of impact craters as a proxy for time: older surfaces tend to accumulate more craters. Using impact craters, we can assess the exposure age and therefore organic preservation potential of the Martian surface from orbit.
The goal of this ongoing project is to better understand exposure ...
Index, 2019 University of Nebraska - Lincoln
Bulletin of the University of Nebraska State Museum
No abstract provided.
The Brule-Gering (Oligocene-Miocene) Contact In The Wildcat Ridge Area Of Western Nebraska, 2019 University of Nebraska - Lincoln
The Brule-Gering (Oligocene-Miocene) Contact In The Wildcat Ridge Area Of Western Nebraska, C. Bertrand Schultz, Charles H. Falkenbach, Carl F. Vondra
Bulletin of the University of Nebraska State Museum
The contact between the Brule Formation (Oligocene) and the Gering Formation (Miocene) can be readily distinguished in the Wildcat Ridge area, as elsewhere in western Nebraska. At the critical fossiliferous exposures at Castle Rock in Scotts Bluff County, the contact on the south face between the two formations is defined as 129 feet above the base of the "Upper Ash" bed, which corresponds to the upper portion of Darton's (1899, PI. C, Fig. D, following p. 754) "sandy phase" in the upper part of the Brule. Certain key beds in the Gering Formation can be traced laterally from a ...
Sediment Transport And Channel Morphology Of A Natural And A Leveed Alluvial River, 2019 Louisiana State University and Agricultural and Mechanical College
Sediment Transport And Channel Morphology Of A Natural And A Leveed Alluvial River, Bo Wang
LSU Master's Theses
Alluvial rivers are shaped by interactions of flow and sediment transport. Their lower reaches to the world’s oceans are highly dynamic, often presenting engineering and management challenges. This thesis research aimed to investigate channel dynamics and sediment transport in a natural river and a highly engineered river in South Louisiana, in order to gain much-needed science information for helping develop sustainable practices in river engineering, sediment management, and coastal restoration and protection. Especially, the thesis research examined (1) riverbed deformation from bank to bank in the final 500-km reach of the Mississippi River, (2) bed material transport at the ...
Effectiveness Of Four Water-Bearing Zones Of The Glacierized Basin In Meltwater Runoff Modeling, 2019 University of Dayton
Effectiveness Of Four Water-Bearing Zones Of The Glacierized Basin In Meltwater Runoff Modeling, Umesh K. Haritashya
Umesh K. Haritashya
Meltwater runoff modeling from glacierized basins needs several input data, including total meltwater contributing area. This study utilizes optical remote sensing data to assess glacierized basins in the central Himalayas where snow and glaciers contribute substantially to the water resources. Result shows that there are four main water-bearing zones in the basin: (a) dry snow, (b) wet snow, (c) exposed glacial ice, and (d) debris-covered glacial ice, and it is possible to differentiate and map these zones and their spatio-temporal variations from satellite sensor data. These zones can then be incorporated in meltwater runoff modeling as separate entities because they ...
Cave Dripwater Isotopic Signals Related To The Altitudinal Gradient Of Mount-Lebanon: Implication For Speleothem Studies, 2019 Laboratoire IDEES UMR 6266 CNRS and Vrije Universiteit Brussel
Cave Dripwater Isotopic Signals Related To The Altitudinal Gradient Of Mount-Lebanon: Implication For Speleothem Studies, Carole Nehme, Sophie Verheyden, Fadi H. Nader, Jocelyne Adjizian-Gerard, Dominique Genty, Kevin De Bont, Benedicte Minster, Ghada Salem, David Verstraten, Philippe Clayes
International Journal of Speleology
An important step in paleoclimate reconstructions based on vadose cave carbonate deposits or speleothems is to evaluate the sensitivity of the cave environment and speleothems to regional climate. Accordingly, we studied four caves, located at different altitudes along the western flank of Mount-Lebanon (Eastern Mediterranean). The objectives of this study are to identify the present-day variability in temperature, pCO2, and water isotopic composition and to assess the possible influence of the altitudinal gradient on cave drip waters and cave streams. We present here an overview of the spatial variability of rainwater based on local and regional data, and we ...
Engaging The Greater Lafayette Community In A Journey Through The Earth Sciences: Purdue’S Eaps Earth Science Passport Day Event, Dara Laczniak, Bradley Garczynski
Engagement & Service-Learning Summit: Connecting Through Listening & Scholarship
No abstract provided.
Investigation Into Strath Terrace Production In The Mud Hills, California, 2019 California Polytechnic State University, San Luis Obispo
Investigation Into Strath Terrace Production In The Mud Hills, California, Patrick Morley Miller
Natural Resources Management and Environmental Sciences
Rainbow Basin and Owl Canyon comprise deeply dissected uplands in the Mud Hills region near Barstow, California in the western portion of the Basin and Range geologic province. These erosional landscapes are formed in sediment deposited in a Miocene-time extensional basin. The basin was then filled with sediment before being inverted due to tectonic uplift beginning roughly 10 Ma. Sometime after 250 to 300 ka strath terraces were produced and preserved in the two drainage basins in Rainbow Basin, but not in the single drainage basin of Owl Canyon. The reason behind this difference is the main problem to be ...
Nebraska Statewide Groundwater-Level Monitoring Report 2018, 2019 University of Nebraska-Lincoln
Nebraska Statewide Groundwater-Level Monitoring Report 2018, Aaron R. Young, Mark E. Burbach, Leslie M. Howard, Michele M. Waszgis, Sue Olafsen Lackey, Robert Matthew Joeckel
Conservation and Survey Division
The term “groundwater” has come to be all but synonymous with Nebraska. Nearly three-quarters of the total volume of the High Plains Aquifer lies beneath the State. Groundwater maintains our streams, our ecosystems, our people, and our vitally important agricultural economy. Nebraska’s total groundwater resource is vast, yet it is also vulnerable to natural and anthropogenic changes, necessitating a long-term commitment to wise management through informed decision making. Monitoring, studying, and reporting form the essential basis for such management and, ultimately, for meeting the myriad challenges presented by change.
The personnel of the Conservation and Survey Division (CSD) are ...
Informing Water Use Decision-Making For Waterfowl And Agricultural Production On A Ranch Along The North Platte River, Nebraska, 2019 University of Nebraska - Lincoln
Informing Water Use Decision-Making For Waterfowl And Agricultural Production On A Ranch Along The North Platte River, Nebraska, Douglas R. Hallum P.G.
Conservation and Survey Division
In 2014, operators of a ranch along the North Platte River approached Conservation and Survey Division seeking expertise to interpret data collected on their ranch. The interpretations inform ranch decisions to accomplish operators’ goals. This publication documents the work by: 1) characterizing the ranch, 2) summarizing data collected, 3) characterizing hydrogeology of the site and the adjacent reach, and 4) conceptualizing groundwater/surface water interaction.
The ranch is a recreation property and a migratory waterfowl refuge with a few general goals: 1) develop and maintain high-quality wet meadow habitat, 2) maximize the extent and duration of surface water on the ...
Short Communication: Challenges And Applications Of Structure-From-Motion Photogrammetry In A Physical Model Of A Braided River, Peter Ashmore, Pauline Leduc, Sarah Peirce
For extending the applications of structure-from-motion (SfM) photogrammetry in river flumes, we present the main challenges and methods used to collect a large dataset ( > 1000 digital elevation models, DEMs) of high-quality topographic data using close-range SfM photogrammetry. Automatic target detection, batch processing, and considerations for image quality were fundamental to the successful implementation of the SfM technique on such a large dataset, which was used primarily for capturing details of gravel-bed braided river morphodynamics and sedimentology. While the applications of close-range SfM photogrammetry are numerous, we include sample results from DEM differencing, which was used to quantify morphology change and ...
Topovar90m: Global High-Resolution Topographic Variables For Environmental Modeling, 2019 Yale University
Topovar90m: Global High-Resolution Topographic Variables For Environmental Modeling, Giuseppe Amatulli Dr.
Yale Day of Data
Topographical relief involves the vertical and horizontal variation of the Earth's terrain and it drives processes in hydrology, climatology, geography and ecology. Its assessment and characterization is fundamental for various types of modeling and simulation analysis. In this regard, the Multi-Error-Removed Improved Terrain (MERIT) Digital Elevation Model (DEM) currently provides the best high-resolution DEM globally available, at a 3 arc-second resolution (90m), due to the removal of multiple error components from the underlying SRTM3 and AW3D30 DEMs. To depict topographical variations worldwide, we developed a new dataset comprising different terrain features derived from the MERIT-DEM. The fully standardized topographical ...
Process Units River Evaluation (Pure) Method For River Corridor Delineation, 2019 University of Massachusetts Amherst
Process Units River Evaluation (Pure) Method For River Corridor Delineation, John D. Gartner, Christine E. Hatch
River corridors are defined as areas adjacent to rivers that are likely to affect and be affected by river and floodplain processes. Geomorphic and hydrologic models can be used to delineate river corridors to address fundamental questions, such as which parts of the fluvial landscape are most likely to respond to climate and land-use change. Land managers are also increasingly using river corridors for applied purposes such as hazard avoidance, ecological conservation, and water quality protection. Currently, the most-used river corridor delineation methods rely on historic maps, field surveys, and/or calibrated empirical models which may be time-intensive, subjective, or ...
Geomorphic Effects Of Engineered Log Structures And Response To A Catastrophic Flood Event In A Missouri Ozarks River, 2019 Missouri State University
Geomorphic Effects Of Engineered Log Structures And Response To A Catastrophic Flood Event In A Missouri Ozarks River, Joseph S. Nash
MSU Graduate Theses
Engineered log structures (ELSs) composed of local tree logs have been installed in river channels throughout the Pacific Northwest as a restoration technique. However, ELSs have not been tested for use in the Ozark Highlands until recently. In October 2016 the U.S. Forest Service installed four ELSs to stabilize banks along the North Fork of the White River in Ozark County, Missouri. The purpose here is to report on monitoring studies of pre- and post-restoration channel conditions and to assess geomorphic responses to floods. Over a ten-day period in April 2017 there were two bankfull floods, and on April ...
Publications And Other Works By R. F. Diffendal, Jr., 2019 University of Nebraska - Lincoln
Publications And Other Works By R. F. Diffendal, Jr., Robert F. Diffendal
Papers in Natural Resources
Chapters in Books
Newspaper and Other Articles
Manuscripts Accepted (A) , Submitted (S) or In Preparation (P)
Geologic Maps in Press
Updated January 2019
Maps Showing The Physical Hydrogeology And Changes In Saturated Thickness (Predevelopment To Spring 2016 And Spring 2011 To Spring 2016) In The Middle Republican Natural Resources District, Southwestern Nebraska., 2019 University of Nebraska-Lincoln
Maps Showing The Physical Hydrogeology And Changes In Saturated Thickness (Predevelopment To Spring 2016 And Spring 2011 To Spring 2016) In The Middle Republican Natural Resources District, Southwestern Nebraska., Jesse T. Korus Dr., Leslie M. Howard
Conservation and Survey Division
This report accompanies fourteen new maps summarizing the hydrogeology and changes in saturated thickness in the Middle Republican Natural Resources District (MRNRD). The purpose of these maps is to assist the MRNRD in their groundwater management programs and in planning and installing an observation well network. Maps include:
• base of the principal aquifer;
• water table surfaces for predevelopment, Spring 2011, and Spring 2016;
• saturated thicknesses for predevelopment, Spring 2011, and Spring 2016;
• changes in saturated thickness (both in absolute magnitude and in percent) from predevelopment to Spring 2016 and from Spring 2011 to Spring 2016;
A series of comprehensive ...
Response Of Vegetation In Open And Partially Wooded Fens To Prescribed Burning At Seney National Wildlife Refuge, 2019 U.S. Department of the Interior & U.S. Geological Survey
Response Of Vegetation In Open And Partially Wooded Fens To Prescribed Burning At Seney National Wildlife Refuge, Jane E. Austin, Wesley E. Newton
Publications of the US Geological Survey
The health and function of northern peatlands, particularly for fens, are strongly affected by fire and hydrology. Fens are important to several avian species of conservation interest, notably the yellow rail (Coturnicops noveboracensis). Fire suppression and altered hydrology often result in woody encroachment, altering the plant community and structure. Woody encroachment and its effects on biodiversity have become an increasing concern in the conservation and management of plant communities. This study evaluated the effects of spring and summer prescribed burns on the plant community, cover, and structure in open and partially wooded fens at Seney National Wildlife Refuge, Michigan, using ...
Stream Dynamics In The Headwaters Of Post-Glacial Watershed Systems, 2018 University of Maine
Stream Dynamics In The Headwaters Of Post-Glacial Watershed Systems, Brett Gerard
Electronic Theses and Dissertations
This dissertation summarizes research examining watershed processes across Northern New England, with an emphasis on the Central and Coastal regions of Maine. The research presented here focuses on the linkages between watershed geomorphic conditions, climate, and surface flow regimes driving stream channel hydraulic conditions and bed dynamics governing channel geometry. The geologic and human history of the landscape provides the context in which earth surface processes are examined within the dominant physiographic settings in Maine to describe vulnerabilities to climate change. Results are summarized to support the development of sustainability solutions for forecasted watershed management problems by natural resource management ...
Geomorphology Of Shell Ridges And Their Effect On The Stabilization Of The Biloxi Marsh, East Louisiana, 2018 University of New Orleans
Geomorphology Of Shell Ridges And Their Effect On The Stabilization Of The Biloxi Marsh, East Louisiana, Frances R. Crawford
University of New Orleans Theses and Dissertations
Extensive shell ridges frame the edges of marsh platforms in parts of the Biloxi Marsh of southeast Louisiana. The exact sources of the shells in these accumulations have not been clearly identified but the most likely source is a combination of shells from modern offshore and shells excavated from buried St. Bernard delta deposits. Larger or fetch-protected ridges remain stable through time, whereas ridges facing open water are more mobile, moving as much as 38 m inland from July 2017 to January 2018. Behind stable ridges, marsh platform biomass is relatively unaffected. When ridges are mobile, vegetation is smothered, leaving ...
Late Quaternary Evolution And Stratigraphic Framework Influence On Coastal Systems Along The North-Central Gulf Of Mexico, Usa, 2018 The University of Southern Mississippi
Late Quaternary Evolution And Stratigraphic Framework Influence On Coastal Systems Along The North-Central Gulf Of Mexico, Usa, Robert Hollis
Coastal systems in the Gulf of Mexico are threatened to reduced sediment supply, storm impacts and relative sea level rise (RSLR). The geologic record can provide insights of geomorphic threshold crossings (formation, progradation, transgression, destruction) to these forcing mechanisms to predict future barrier evolution to climate change. The stratigraphic framework and antecedent topography directly influence coastal evolution over geologic timescales. This study synthesizes ~2100km of geophysical data, 700+ sediment cores, and 63 radiocarbon dates to regionally map two sequence boundaries, multiple ravinement surfaces and fourteen depositional facies. One marine isotope stage (MIS) 6 valley’s fill provided up to 300 ...