Digital Commons Network^™

The Influence Of Föhn Winds On Glacial Lake Washburn And Palaeotemperatures In The Mcmurdo Dry Valleys, Antarctica, During The Last Glacial Maximum, Maciej Obryk, Peter Doran, Ed Waddington, Chris Mckay

Geology Faculty Publications and Presentations

Large glacial lakes, including Glacial Lake Washburn, were present in the McMurdo Dry Valleys, Antarctica, during the Last Glacial Maximum (LGM) despite a colder and drier climate. To address the mechanism capable of generating enough meltwater to sustain these large lakes, a conceptual model was developed based on the warming potential of infrequent contemporary föhn winds. The model suggests that föhn winds were capable of generating enough meltwater to sustain large glacial lakes during the LGM by increasing degree days above freezing (DDAF) and prolonging the melt season. A present-day relationship between infrequent summer föhn winds and DDAF was established. …

Seismic Azimuthal Anisotropy Beneath The Eastern United States And Its Geodynamic Implications, Bin B. Yang, Yunhua Liu, Haider Dahm, Kelly H. Liu, Stephen S. Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Systematic spatial variations of anisotropic characteristics are revealed beneath the eastern U.S. using seismic data recorded between 1988 and 2016 by 785 stations. The resulting fast polarization orientations of the 5613 measurements are generally subparallel to the absolute plate motion (APM) and are inconsistent with the strike of major tectonic features. This inconsistency, together with the results of depth estimation using the spatial coherency of the splitting parameters, suggests a mostly asthenospheric origin of the observed azimuthal anisotropy. The observations can be explained by a combined effect of APM-induced mantle fabric and a flow system deflected horizontally around the edges …

Determining Annual Cryosphere Storage Contributions To Stream Flow Using Historical Hydrometric Records, Janice Brahney, Brian Menounos, Xiaohua Wei, Paul Jefferson Curtis

Watershed Sciences Faculty Publications

Alpine glaciers and perennial snow fields are important hydrologic elements in many mountain environments providing runoff during the late summer and during periods of drought. Because relatively long records of glacier mass–balance data are absent from many glacierized catchments, it remains unclear to what extent shrinking perennial snow and glaciers have affected runoff trends from these watersheds. Here, we employ a hydrograph separation technique that uses a double mass curve in an attempt to isolate changes in runoff due to glacier retreat and disappearance of perennial snow. The method is tested using hydrometric data from 20 glacierized and 16 nonglacierized …

Rapid Surface-Water Volume Estimations In Beaver Ponds, Daniel J. Karran, Cherie J. Westbrook, Joseph Michael Wheaton, Carol A. Johnston, Angela Bedard-Haughn

Watershed Sciences Faculty Publications

Beaver ponds are surface-water features that are transient through space and time. Such qualities complicate the inclusion of beaver ponds in local and regional water balances, and in hydrological models, as reliable estimates of surface-water storage are difficult to acquire without time- and labour-intensive topographic surveys. A simpler approach to overcome this challenge is needed, given the abundance of the beaver ponds in North America, Eurasia, and southern South America. We investigated whether simple morphometric characteristics derived from readily available aerial imagery or quickly measured field attributes of beaver ponds can be used to approximate surface-water storage among the range …

Surficial Geology Of The Saybrook 7.5-Minute Quadrangle, Mclean County, Illinois, Usa, Ellyn S. Rickels, Andrew J. Stumpf, David H. Malone, William E. Shields

Faculty Publications - Geography, Geology, and the Environment

This project involved the construction of a surficial (Quaternary) geologic map of part of McLean County, Illinois. The Saybrook 7.5-minute Quadrangle (scale 1:24,000) was the focus area. The quadrangle largely covers rural agricultural land, but also contains the small town of Saybrook. Multiple, major episodes of glaciation over the past 1,200,000 years have controlled the regional geologic history. The most recent (Wisconsin Episode) glaciation almost exclusively shaped the observed surficial geologic and geomorphic features in the quadrangle. Field observations, USDA soil survey data, private water well data, sparse stratigraphic borehole information, and LIDAR elevation data were used to construct the …

Watershed Response To Climate Change And Fire-Burns In The Upper Umatilla River Basin, Usa, Kimberly Crystal Yazzie, Heejun Chang

Geography Faculty Publications and Presentations

This study analyzed watershed response to climate change and forest fire impacts in the upper Umatilla River Basin (URB), Oregon, using the precipitation runoff modeling system. Ten global climate models using Coupled Intercomparison Project Phase 5 experiments with Representative Concentration Pathways (RCP) 4.5 and 8.5 were used to simulate the effects of climate and fire-burns on runoff behavior throughout the 21st century. We observed the center timing (CT) of flow, seasonal flows, snow water equivalent (SWE) and basin recharge. In the upper URB, hydrologic regime shifts from a snow-rain-dominated to rain-dominated basin. Ensemble mean CT occurs 27 days earlier in …

Investigation Of Firn Aquifer Structure In Southeastern Greenland Using Active Source Seismology, Lynn N. Montgomery, Nicholas Schmerr, Scott Burdick, Richard R. Forster, Lora Koenig, Anatoly Legchenko, Stefan Ligtenberg, Clément Miège, Olivia L. Miller, D. Kip Solomon

Environmental Science and Geology Faculty Research Publications

In spring of 2011, a perennial storage of water was observed in the firn of the southeastern Greenland Ice Sheet (GrIS), a region of both high snow accumulation and high melt. This aquifer is created through percolation of surface meltwater downward through the firn, saturating the pore space above the ice-firn transition. The aquifer may play a significant role in sea level rise through storage or draining freshwater into the ocean. We carried out a series of active source seismic experiments using continuously refracted P-waves and inverted the first P-arrivals using a transdimensional Bayesian approach where the depth, velocity, and …

Estimating The Frequency Of Volcanic Ash Clouds Over Northern Europe, Elizabeth J. Watson, Graeme T. Swindles, Ivan P. Savov, Ian T. Lawson, Charles B. Connor, J. A. Wilson

School of Geosciences Faculty and Staff Publications

Fine ash produced during explosive volcanic eruptions can be dispersed over a vast area, where it poses a threat to aviation, human health and infrastructure. Here, we focus on northern Europe, which lies in the principal transport direction for volcanic ash from Iceland, one of the most active volcanic regions in the world. We interrogate existing and newly produced geological and written records of past ash fallout over northern Europe in the last 1000 years and estimate the mean return (repose) interval of a volcanic ash cloud over the region to be 44±7 years. We compare tephra records …

Seed Dormancy-Breaking In A Cold Desert Shrub In Relation To Sand Temperature And Moisture, Huiliang Liu, Buhailiqiemu Abudureheman, Lingwei Zhang, Jerry M. Baskin, Carol C. Baskin, Daoyuan Zhang

Biology Faculty Publications

Seasonal periodicity of seed germination and its relationship to seasonal changes in temperature and soil moisture have been well studied in seeds of species with physiological dormancy. However, relatively little information is available on the role of these environmental factors in controlling germination of seeds with physical dormancy (PY). Our primary aim was to determine if seeds of the cold desert sand dune semi-shrub Eremosparton songoricum exhibits seasonal periodicity of seed germination and the relationship between seed dormancy break and soil temperature and moisture. In the laboratory, seeds incubated on dry, wet, wet-dry and dry-wet sand were exposed to a …

Effects Of Spatially Distributed Stream Power On Check Dam Function In Small Upland Watersheds: A Case Study Of The Upper Laja Watershed, Guanajuato, Mexico, Zachary Andrew Herzfeld

Dissertations and Theses

Watershed restoration comes in a variety of forms depending on which set of problems are sought to be remedied. Severe soil erosion, in the form of gullying and/or headcutting, can be mitigated through constructing check dams in well-selected locations. This practice has been used throughout the upland subwatersheds within the Upper Laja River watershed in Guanajuato, México. The present study employed Wolman pebble counts to systematically assess the effectiveness of 21 check dams located near the city of San Miguel de Allende. Particle size distributions taken directly downstream and upstream of each check dam were differentiated, aggregated and compared--with the …

Petrographical And Geochemical Changes In Bosnian Stalagmites And Their Palaeo-Environmental Significance, Veronica Chiarini, Isabelle Couchoud, Russell Drysdale, Petra Bajo, Simone Milanolo, Silvia Frisia, Alan Greig, John Hellstrom, Jo De Waele

International Journal of Speleology

Detailed petrographic observations have been coupled with trace element and δ¹³C - δ¹⁸O analyses in order to investigate their dynamics in two Holocene Bosnian speleothems. The potential of this multiproxy approach in providing a means to extract palaeo-environmental information from stalagmites whose stable isotope signals are noisy and without obvious trends has been tested. The studied stalagmites are mostly characterized by columnar microcrystalline fabric. At the sub-millimetre scale of lamination, different microcrystalline columnar sub-types (open and closed) have been detected and classified on the basis of the observed porosity and the crystallite size. The presence of …

A Twenty-Year Look At “Computational Geology,” An Evolving, In-Discipline Course In Quantitative Literacy At The University Of South Florida, Victor J. Ricchezza, H. L. Vacher

Numeracy

Since 1996, the Geology (GLY) program at the USF has offered “Computational Geology” as part of its commitment to prepare undergraduate majors for the quantitative aspects of their field. The course focuses on geological-mathematical problem solving. Over its twenty years, the course has evolved from a GATC (geometry-algebra-trigonometry-calculus) in-discipline capstone to a quantitative literacy (QL) course taught within a natural science major. With the formation of the new School of Geosciences in 2013, the merging departments re-examined their various curricular programs. An online survey of the Geology Alumni Society found that “express quantitative evidence in support of an argument” was …

Discovery And Geology Of The Guinness World Record Lake Copper, Lake Superior, Michigan, Theodore J. Bornhorst, Robert Barron

A. E. Seaman Mineral Museum Publications

No abstract provided.

Pathways To Increasing Farmer-Led Investments In Sustainable Agricultural Water Management In Sub-Saharan Africa, Douglas J. Merrey, Peter G. Mccornick, Molly C. Nance

Daugherty Water for Food Global Institute: Faculty Publications

Without a transformative leap forward in the use of irrigation, Africa will continue falling short in the struggle to feed its growing population, improve its people’s nutrition, grow its economies, adapt to the impacts of climate change, and eliminate poverty. While Africans must lead this transformation for it to be successful, the international community can help African countries substantially increase the use of more productive and sustainable water management practices and unlock the potential of farmer-led irrigated agriculture. Achieving highly productive irrigated agricultural systems in Africa requires an enabling environment that facilitates the full engagement of farmers, public and private …

Multi-Year Modis Active Fire Type Classification Over The Brazilian Tropical Moist Forest Biome, David P. Roy, S. S. Kumar

GSCE Faculty Publications

The Brazilian Tropical Moist Forest Biome (BTMFB) spans almost 4 million km² and is subject to extensive annual fires that have been categorized into deforestation, maintenance, and forest fire types. Information on fire types is important as they have different atmospheric emissions and ecological impacts. A supervised classification methodology is presented to classify the fire type of MODerate resolution Imaging Spectroradiometer (MODIS) active fire detections using training data defined by consideration of Brazilian government forest monitoring program annual land cover maps, and using predictor variables concerned with fuel flammability, fuel load, fire behavior, fire seasonality, fire annual frequency, proximity …

2016/17 Dry Run Creek Geomorphological Watershed Assessment, University Of Northern Iowa. Department Of Earth And Environmental Sciences.

UNI Conservation Corps Projects

Dry Run Creek (DRC) watershed is a primary drainage basin located in northwestern Black Hawk County (Figure 1). It is fed predominantly by agricultural runoff in its upper reaches, and becomes heavily urbanized as it travels through the city of Cedar Falls, before draining into the Cedar River. The stream is perennial, however some are tiled and new segments have developed both naturally and artificially. Re-evaluation of the creek is underway and indicates some changes in urban and rural areas. Data was collected between Fall 2016 & Fall 2017 by University of Northern Iowa geomorphology students, using handheld GPS devices …

Nebraska, Usa: Wonderful Fossils, Natural History Museums And Public Art Depicting Fossils, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Nebraska is known by vertebrate palaeontologists as the place in North America where there is a very complete Cenozoic geologic record of mammalian evolution over the last thirty-five million years or so. All you have to do is visit any of the many major natural history museums in the USA and in many countries around the world, including the UK, to see fossil skulls, articulated skeletons and large slabs of rock containing bones of fossil mammals from Nebraska to verify this assertion. Nebraska is also the site of Cretaceous rocks containing the oldest known Cretaceous fossil flower and many other …

A Photosynthesis-Based Two-Leaf Canopy Stomatal Conductance Model For Meteorology And Air Quality Modeling With Wrf/Cmaq Px Lsm, Limei Ran, Jonathan Pleim, Conghe Song, Larry Band, John T. Walker, Francis S. Binkowski

United States Environmental Protection Agency: Publications

A coupled photosynthesis-stomatal conductance model with single-layer sunlit and shaded leaf canopy scaling is implemented and evaluated in a diagnostic box model with the Pleim-Xiu land surface model (PX LSM) and ozone deposition model components taken directly from the meteorology and air quality modeling system—WRF/CMAQ (Weather Research and Forecast model and Community Multiscale Air Quality model). The photosynthesis-based model for PX LSM (PX PSN) is evaluated at a FLUXNET site for implementation against different parameterizations and the current PX LSM approach with a simple Jarvis function (PX Jarvis). Latent heat flux (LH) from PX PSN is further evaluated at five …

Evaporite Karst Geohazards In The Delaware Basin, Texas: Review Of Traditional Karst Studies Coupled With Geophysical And Remote Sensing Characterization, Kevin W. Stafford, Wesley A. Brown, Jon T. Ehrhart, Adam F. Majzoub, Jonathan D. Woodard

Faculty Publications

Evaporite karst throughout the Gypsum Plain of west Texas is complex and extensive, including manifestations ranging from intrastratal brecciation and hypogene caves to epigene features and suffosion caves. Recent advances in hydrocarbon exploration and extraction has resulted in increased infrastructure development and utilization in the area; as a result, delineation and characterization of potential karst geohazards throughout the region have become a greater concern. While traditional karst surveys are essential for delineating the subsurface extent and morphology of individual caves for speleogenetic interpretation, these methods tend to underestimate the total extent of karst development and require surficial manifestation of karst …

Socio-Environmental Drought Response In A Mixed Urban-Agricultural Setting: Synthesizing Biophysical And Governance Responses In The Platte River Watershed, Nebraska, Usa, Samuel C. Zipper, Kelly Helm Smith, Betsy Breyer, Jianxiao Qui, Anthony Kung, Dustin Herrmann

National Drought Mitigation Center: Faculty Publications

Ensuring global food and water security requires a detailed understanding of how coupled socio-environmental systems respond to drought. Using the Platte River Watershed in Nebraska (USA) as an exemplar mixed urban-agricultural watershed, we quantify biophysical response to drought in urban (Lincoln NE) and agricultural systems alongside a qualitative analysis of governance response and adaptive capacity of both sectors. Synthesis of results highlights parallels and discontinuities between urban and agricultural preparations for and response to drought. Whereas drought prompted an increase in well installations and expansion of water-intensive crops, e.g., corn, in the agricultural sector, outdoor water use restrictions rapidly curtailed …

Geosciences Newsletter - 2017, Department Of Geosciences

Geological and Environmental Sciences News

Vol. 10, No. 1

• Greetings from the Chair
• Faculty and Staff Roster
• Faculty Updates
• Hydrogeology Field Course and Hydrogeology Certificate
• Notes from Field Mapping Course
• CoreKids
• Michigan Geological Survey
• MGRRE—Michigan Geological Repository for Research and Education
• Distinguished Alumni Award
• Advisory Council
• Endowments and Corporate Donors
• Individual Donors and Grants
• Student Scholarships and Awards
• Department Publications
• Graduate Student Updates
• New Graduate Students
• Geology Club
• AAPG
• SEG
• Department Photos

Morpho-Sedimentary Characteristics Of Proximal Gravel Braided River Deposits In A Froude-Scaled Physical Model, Peter Ashmore, Tobias Gardner, Pauline Leduc

Geography & Environment Publications

A Froude‐scaled physical model of a proximal gravel‐bed braided river was used to connect the river morphological characteristics, and sedimentary processes and forms, to deposit geometry. High resolution continuous three‐dimensional topographic data were acquired from sequential photogrammetric digital elevation models paired with grain‐size surface maps derived from image analysis of textural properties of the surface. From these data, the full three‐dimensional development of the braided river deposit and grain‐size sorting patterns was compiled over an experimental time period of 41 h during which the model river reworked a large portion of the braided channel. The minimum surface of the deposit …

Camera System Considerations For Geomorphic Applications Of Sfm Photogrammetry, Adam R. Mosbrucker, Jon J. Major, Kurt R. Spicer, John Pitlick

United States Geological Survey: Staff Publications

The availability of high-resolution, multi-temporal, remotely sensed topographic data is revolutionizing geomorphic analysis. Three-dimensional topographic point measurements acquired from structure-from-motion (SfM) photogrammetry have been shown to be highly accurate and cost-effective compared to laser-based alternatives in some environments. Use of consumer-grade digital cameras to generate terrain models and derivatives is becoming prevalent within the geomorphic community despite the details of these instruments being largely overlooked in current SfM literature.

A practical discussion of camera system selection, configuration, and image acquisition is presented. The hypothesis that optimizing source imagery can increase digital terrain model (DTM) accuracy is tested by evaluating accuracies …

The Prairie Post Quarterly Newsletter Of The High Plains Regional Climate Center- January 2017, Natalie Umphlett, Jamie Lahowetz, Bill Sorensen, Crystal J. Stiles

Prairie Post: Quarterly Newsletter of the High Plains Regional Climate Center

Inside this issue:

Message from the interim director........................................1

30th anniversary......................1

Stakeholder engagement activities......................................2

Product highlights..................3

AWDN information.................4

Update on regional climate conditions..................................4

Services update........................5

Recent and upcoming travel and activities.............................6

Local To Global: Developing Solutions And Creating Impacts. Annual Report Fy 2017, Robert B. Daugherty Water For Food Global Institute

Daugherty Water for Food Global Institute: Administrative Materials

FOREWORD - Hank M. Bounds, President, University of Nebraska

PREFACE - Peter G. McCornick, Executive Director

Focus Areas: Where we are headed We are committed to helping the world efficiently use its limited freshwater resources to ensure food security for current and future generations. The diversity of projects and activities in this report reflects the complexity of the challenges we face in achieving this goal through technical and policy research, education and communication. Our research and policy development efforts are focused within five areas to maximize the expertise of DWFI staff, our colleagues at the National Drought Mitigation Center (NDMC) …

A Model-Based Assessment Of Potential Impacts Of Man-Made Reservoirs On Precipitation, Jesse Winchester, Rezaul Mahmood, William Rodgers, Faisal Hossain, Eric Rappin, Joshua D. Durkee, Themis Chronis

High Plains Regional Climate Center: Staff Publications

Land-use land-cover change (LULCC) plays an important role in weather and climate systems. Human modifications of land cover include building reservoirs and thus creating artificial lakes for multipurpose use. In this research, the authors have completed a Weather Research and Forecasting (WRF) Model–based assessment of impacts of two large parallel lakes on precipitation. This area is located in the western part of the states of Kentucky and Tennessee and known as the Land between the Lakes (LBL). To determine the impacts, this study has replaced the lakes with grass, deciduous forests, and bare soil and conducted model simulations for three …

2016 Nebraska Water Leaders Academy - Final Report, Mark E. Burbach, Connie Reimers-Hild

Conservation and Survey Division: Faculty and Staff Publications

The effective management of Nebraska’s water resources is evermore challenged by variations in weather, climate, technology, socioeconomic policies, and regulation. Anthropogenic climate change, declining water tables and stream flows, increasing demands on freshwater, aging water infrastructure, fiscal constraints, and impacts on aquatic organisms are particularly imminent challenges in Nebraska and around the world (Pahl-Wostl et al., 2013; Pittock et al., 2008; USACE, 2010). Sustaining freshwater ecosystem services in the face of emerging environmental threats presents an immense societal dilemma worldwide (Pittock et al., 2013; Rockström et al., 2009, Millenium Ecosystem Assessment, 2005). The rapidly changing conditions of water resources in …

Terrestrial-Marine Sedimentary Cycles In The South Yellow Sea, China: Implications For Paleoenvironmental Reconstruction Since Mis 5, Liangtao Ye, Ge Yu, Mengna Liao, Shouyun Hu, Longsheng Wang, Lei Gao

Turkish Journal of Earth Sciences

Sedimentary records of the continental shelves since Marine Isotope Stage (MIS) 5 are valuable for paleoenvironmental reconstruction and decipherment of land-sea interactions. Since the 1990s, different perspectives on global glacioclimate magnitudes and the associated evolution of major sedimentary environments during the Late Pleistocene have caused a distinctive understanding of marine transgressions and coastal deposits during MIS 3 and MIS 5. Moreover, the chronology of sediment sequences from this region was primarily determined based on radiocarbon dating, which might be problematic for deposits of 40-50 ka BP or older. In this study, we used both a 150-m-long sedimentary core (YZ07) as …

Karstic Depressions On Bolkar Mountain Plateau, Central Taurus (Turkey):Distribution Characteristics And Tectonic Effect On Orientation, Muhammed Zeynel Öztürk, Mesut Şi̇mşek, Mustafa Utlu, Mehmet Furkan Şener

Turkish Journal of Earth Sciences

This study investigates the spatial distribution characteristics of karstic depressions that developed on a 2558 km2 plateau with gently sloping in neritic (reef) limestones in the western section of the Bolkar Mountains. The 30,132 karstic depressions identified are located at elevations between 1315 and 2525 m, while 31°/km2 slope and 5.6 km/km2 drainage density are limited to the spatial distribution of depressions. In the central section of the study area at the anticlinal surface, maximum density (99 depressions/km2) is reached between elevations of 1930 and 2080 m. The orientation of depressions is predominantly NE-SW. However, in the same area, the …

America's National Parks And The Anthropocene: Addressing The Present To Accommodate The Future In Acadia National Park, Sophie A. Swetz

Honors Theses

In 2000, atmospheric chemist, Paul J. Crutzen, and limnologist, Eugene Stoermer, formally proposed the idea of “the Anthropocene,” a new geologic epoch in which humans are the dominant force shaping the Earth. To claim the Anthropocene's existence is to declare that human actions have altered the Earth in such a way that geologic indicators render it a distinct epoch in the stratification of geologic time. This new epoch emerges as a consequence of increased technological development employed to accommodate an anthropocentric human existence. That is, rapid advancements in technology have driven the transformation from a primarily naturally controlled planet to …