Other Earth Sciences Commons^™

The “World's Greatest Mineral Locality:” HaiǁOm, Ndonga, Herero, And The Early Colonial Histories Of Tsumeb, Namibia, Selby Hearth

Geology Faculty Research and Scholarship

The Tsumeb copper mine in the Otavi Mountains of Namibia is famous both for its spectacular mineral specimens and for its unparalleled diversity of mineral species. The site was mined for nearly 100 years, first by Anglo-German and then by multinational companies; however, prior to that, the site was central to the economies of the Ndonga, Haiǁom, and Herero, who mined, smelted, crafted, and traded the copper. This paper attempts to fill a major gap in the early history of Tsumeb: how did control of Tsumeb’s copper transfer from local communities to Germany? By synthesizing a wide variety of sources, …

Atmosphere/Landscape Co2 Interactions In Mammoth Cave National Park: Hydrochemistry Of Cascade River, Great Onyx Cave, Jessica Williams

Mahurin Honors College Capstone Experience/Thesis Projects

High-resolution analysis of water/CO₂/carbonate rock geochemistry was conducted at the Great Onyx Groundwater Basin in Mammoth Cave National Park. The purpose of this work has been to undertake hydrochemical characterization of the karst groundwater in Cascade River, the largest cave stream in the upper level of Great Onyx Cave, which is below a relatively pristine karst landscape.

Hydrochemical monitoring of Cascade River at Biz Falls using field, laboratory, and high-resolution electronic data-sonde measurements has provided a detailed picture of the stream’s behavior with respect to the transport and influence of carbon dioxide in the surface and groundwater system …

Characterizing The Geomagnetic Field At High Southern Latitudes: Evidence From The Antarctic Peninsula, Joseph Biasi, Joseph Kirschvink, Roger Fu

Other Staff Materials

Due to a dearth of data from high-latitude paleomagnetic sites, it is not currently clear if the geocentric axial dipole (GAD) hypothesis accurately describes the long-term behavior of the geomagnetic field at high latitudes. Here we present new paleomagnetic and paleointensity data from the James Ross Island (JRI) volcanic group, located on the Antarctic Peninsula. This data set addresses a notable lack of data from the 60°–70°S latitude bin and includes 251 samples from 31 sites, spanning 0.99–6.8 Ma in age. We also include positive fold, conglomerate, and baked contact tests. Paleointensity data from three methods (Thellier- Thellier, pseudo-Thellier, and …

Whose Ground Truth Is It? Harvesting Lessons From Missouri’S 2018 Bumper Crop Of Drought Observations, Kelly Helm Smith, Mark E. Burbach, Michael Hayes, Patrick Guinan, Andrew Tyre, Brian Fuchs, Tonya Haigh, Mark Svoboda

National Drought Mitigation Center: Faculty Publications

Drought-related decision-making and policy should go beyond numeric hydrometeorological data to incorporate information on how drought affects people, livelihoods, and ecosystems. The effects of drought are nested within environmental and human systems, and relevant data may not exist in readily accessible form. For example, drought may reduce forage growth, compounded by both late-season freezes and management decisions. An effort to gather crowdsourced drought observations in Missouri in 2018 yielded a much higher number of observations than did previous related efforts. Here we examine 1) the interests, circumstances, history, and recruitment messaging that coincided to produce a high number of reports …

Tweetdrought: A Deep-Learning Drought Impacts Recognizer Based On Twitter Data, Beichen Zhang, Frank Schilder, Kelly Helm Smith, Michael Hayes, Sherri Harms, Tsegaye Tadesse

National Drought Mitigation Center: Faculty Publications

Acquiring a better understanding of drought impacts becomes increasingly vital under a warming climate. Traditional drought indices describe mainly biophysical variables and not impacts on social, economic, and environmental systems. We utilized natural language processing and bidirectional encoder representation from Transformers (BERT) based transfer learning to fine-tune the model on the data from the news-based Drought Impact Report (DIR) and then apply it to recognize seven types of drought impacts based on the filtered Twitter data from the United States. Our model achieved a satisfying macro-F1 score of 0.89 on the DIR test set. The model was then applied to …

Developing A Strategy For The National Coordinated Soil Moisture Monitoring Network, Michael H. Cosh, Todd G. Caldwell, C. Bruce Baker, John D. Bolten, Nathan Edwards, Peter Goble, Heather Hofman, Tyson E. Ochsner, Steven Quiring, Charles Schalk, Marina Skumanich, Mark D. Svoboda, Mary E. Woloszyn

National Drought Mitigation Center: Faculty Publications

Soil moisture is a critical land surface variable, affecting a wide variety of climatological, agricultural, and hydrological processes. Determining the current soil moisture status is possible via a variety of methods, including in situ monitoring, remote sensing, and numerical modeling. Although all of these approaches are rapidly evolving, there is no cohesive strategy or framework to integrate these diverse information sources to develop and disseminate coordinated national soil moisture products that will improve our ability to understand climate variability. The National Coordinated Soil Moisture Monitoring Network initiative has developed a national strategy for network coordination with NOAA’s National Integrated Drought …

Evaluation Of Remotely Sensed Precipitation Estimates From The Nasa Power Project For Drought Detection Over Jordan, Muhammad Rasool Al‑Kilani, Michel Rahbeh, Jawad Al‑Bakri, Tsegaye Tadesse, Cody Knutson

National Drought Mitigation Center: Faculty Publications

Droughts can cause devastating impacts on water and land resources and therefore monitoring these events forms an integral part of planning. The most common approach for detecting drought events and assessing their intensity is use of the Standardized Precipitation Index (SPI), which requires abundant precipitation records at good spatial distribution. This may restrict SPI usage in many regions around the world, particularly in areas with limited numbers of ground meteorological stations. Therefore, the use of remotely sensed derived data of precipitation can contribute to drought monitoring. In this study, remotely sensed precipitation estimates from the POWER/Agroclimatology archive of NASA and …

A Novel Strategy To Reconstruct Ndvi Time-Series With High Temporal Resolution From Modis Multi-Temporal Composite Products, Linglin Zeng, Brian Wardlow, Shun Hu, Xiang Zhang, Guoqing Zhou, Guozhang Peng, Daxiang Xiang, Rui Wang, Ran Meng, Weixiong Wu

Center for Advanced Land Management Information Technologies: Publications

Vegetation indices (VIs) data derived from satellite imageries play a vital role in land surface vegetation and dynamic monitoring. Due to the excessive noises (e.g., cloud cover, atmospheric contamination) in daily VI data, temporal compositing methods are commonly used to produce composite data to minimize the negative influence of noise over a given compositing time interval. However, VI time series with high temporal resolution were preferred by many applications such as vegetation phenology and land change detections. This study presents a novel strategy named DAVIR-MUTCOP (DAily Vegetation Index Reconstruction based on MUlti-Temporal COmposite Products) method for normalized difference vegetation index …

Long-Term African Dust Delivery To The Eastern Atlantic Ocean From The Sahara And Sahel Regions: Evidence From Quaternary Paleosols On The Canary Islands, Spain, Daniel R. Muhs, Joaquín Meco, James R. Budahn, Gary L. Skipp, Kathleen R. Simmons, Matthew C. Baddock, Juan F. Betancourt, Alejandro Lomoschitz

United States Geological Survey: Staff Publications

Africa is the most important source of dust in the world today and dust storms from that continent frequently deposit sediment on the nearby Canary Islands. Many investigators have inferred African dust inputs to Canary Islands paleosols based only on the presence of quartz. However, some local rocks do contain this mineral, so quartz alone is insufficient proof of dust deposition. Further, it is not known whether the Sahara Desert or the Sahel region is more important as a dust source. We address these issues by study of sequences of Pleistocene aeolian sands on the islands of Lanzarote and Fuerteventura. …

Eolian Sediments, Daniel R. Muhs

United States Geological Survey: Staff Publications

Eolian (windblown) sediments form some of the world’s most dramatic landscapes and comprise important parts of the geologic record. This article reviews the characteristics, origins, and significance of eolian deposits, including windblown sand, silt, and dust.

Landforms composed of eolian sand, either as dunes or sand sheets, occupy substantial areas over the surface of the Earth (perhaps as much as 6% globally, but over ~20% of the world’s arid zones, according to Pye and Tsoar, 2009). Low-latitude arid or semiarid regions, usually under the influence of subtropical high-pressure cells, are some of the largest areas of eolian sand accumulation (Lancaster, …

Ecology Of An Isolated Muskrat Population During Regional Population Declines, Laken S. Ganoe, Matthew J. Lovallo, Justin D. Brown, W. David Walter

United States Geological Survey: Staff Publications

Evidence indicating a decline in Ondatra zibethicus (Muskrat) populations in the United States during the past 40 years has led to speculation regarding factors influencing Muskrat survival. In order to understand population dynamics and survival, it is important to first define the ecology of local populations. We investigated the dwelling structure use, movements, home range, and survival of radio-tagged Muskrats (n = 14) in an urban wetland complex in central Pennsylvania. We used locations collected from intensive radio-telemetry monitoring to determine number of lodging structures used, hourly movement, and size and percent area overlap of home ranges. Muskrats shared …

Elemental And Radionuclide Exposures And Uptakes By Small Rodents, Invertebrates, And Vegetation At Active And Post-Production Uranium Mines In The Grand Canyon Watershed, Danielle Cleveland, Jo Ellen Hinck, Julia S. Lankton

United States Geological Survey: Staff Publications

The effects of breccia pipe uranium mining in the Grand Canyon watershed (Arizona) on ecological and cultural resources are largely unknown. We characterized the exposure of biota to uranium and cooccurring ore body elements during active ore production and at a site where ore production had recently concluded. Our results indicate that biota have taken up uranium and other elements (e.g., arsenic, cadmium, copper, molybdenum, uranium) from exposure to ore and surficial contamination, like blowing dust. Results indicate the potential for prolonged exposure to elements and radionuclides upon conclusion of active ore production. Mean radium-226 in deer mice was up …

Soils And Paleosols, Daniel R. Muhs

United States Geological Survey: Publications

This article reviews the nature of modern and ancient soils. Soils are naturally occurring bodies that mantle most of the land surface of the Earth. They are found on virtually every part of the Earth’s land surface, other than areas covered by water bodies (lakes and rivers), glacial ice, or steep slopes in mountainous terrain. Soils occur at the interface of the geosphere, hydrosphere, biosphere, and atmosphere and are the medium of growth for much of the Earth’s plant and animal life. The study of soils as naturally occurring bodies on the Earth’s surface is called pedology (in contrast to …

Droughtscape, Winter 2021, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

DroughtScape, Winter 2021

A Karst Feature Prediction Model For Prince Of Wales Island, Alaska Based On High Resolution Lidar Imagery, Alexander Lyles

Master's Theses or Doctor of Nursing Practice

Investigation into surface karst formation is significant to hazard prediction, hydrogeologic drainage, and land management. Southeast Alaska contains over 600,000 acres of mapped carbonate bedrock, and some of the fastest recorded karst dissolution in the world. The objectives of this study are to develop and compare multiple semi-automated models to map and delineate karst features from bare-earth LiDAR imagery using ArcGIS Desktop 10.7, and to apply a preliminary geostatistical analysis of sinkhole morphometric parameters to highlight potential spatial patterns of karst evolution on Prince of Wales Island, Alaska. A semi-automated approach of mapping karst features provides a dataset that minimizes …

Advancement Of Full-Vector Variable-Temperature Magnetometry For Rock-Magnetic And Paleointensity Applications, Leonid Surovitskii

Dissertations, Master's Theses and Master's Reports

Data on the variation of the direction and strength of Earth’s ancient magnetic field (absolute paleointensity) provide crucial information into the mechanisms of the geodynamo and the Earth’s thermal history. However, the use of conventional methods and instrumentation for absolute paleointensity determination has been hampered by physicochemical alteration of the samples caused by multiple high-temperature cycles and long experiment durations. The reliability and efficiency of the measurement process can be improved by the measurement of the full remanent magnetization vector simultaneously with the temperature cycling of a sample. Such as approach can also substantially expand the scope of materials available …

Experiential Learning In Soil Science: Evaluating Soil Quality In South Wollo, Ethiopia, Melissa Allen, Martha Mamo, Shimelis Beyene, Teshome Regassa, Gandura O. Abagandura, Solomon Abreha, Anthony James Mucia, Tsegaye Tadesse

National Drought Mitigation Center: Faculty Publications

This study abroad program provided an opportunity to enhance the international experience and research skills of University of Nebraska-Lincoln (UNL) students within a multidisciplinary team’s research-education goal on improving food security in Ethiopia. The experiential study component of the project included preparatory sessions during the Fall 2015 Semester at the UNL followed by a four- to five-week fieldwork experience in Ethiopia. Teams from the UNL and an Ethiopian university participated in survey data collection and field soil evaluations from farms in the Gerado area of South Wollo, Ethiopia. Having students interact with farmers increased student self-confidence and enhanced their leadership …

Metabarcoding Assays For The Detection Of Freshwater Mussels (Unionida) With Environmental Dna, Katy E. Klymus, Catherine A. Richter, Nathan Thompson, Jo Ellen Hinck, Jess W. Jones

United States Geological Survey: Staff Publications

Freshwater mussels of the order Unionida are a widely distributed taxon that are important in maintaining freshwater ecosystems and are also highly imperiled throughout the world. Monitoring of mussel populations with environmental DNA (eDNA) is an attractive alternative to traditional methods because it is noninvasive and requires less labor and taxonomic knowledge from field personnel. We developed eDNA metabarcoding assays specific to freshwater mussels and tested them at six sites in the Clinch River, located in the southeastern United States. Our objective was to determine the utility of eDNA metabarcoding for future monitoring of mussel populations and restoration efforts in …

Long Term Nutrient And Chlorophyll A Dynamics Across Long Island Sound And Impacts On Dissolved Oxygen Conditions Within The Western Sound (1991-2019), Sherry Perreira

Dissertations and Theses

Nitrogen overload, eutrophication, and hypoxia have been challenging and persistent water quality problems in Long Island Sound (LIS) over the past decades with major impacts on commercial industries, ecology, and recreational activities in the region. Recognizing these problems, the EPA enforced three phases of the Clean Water Act (CWA) to reduce nitrogen loads in an effort to improve this important estuary. This study examines how nitrogen (NH₃, NO_x & TDN), chlorophyll a (CHLA), and dissolved oxygen (DO) concentrations changed in LIS over the past 30 years, in response to water quality regulations as well as changes in …

A "Warm" Or "Cold" Early Mars: Evidence From Valley Networks, Xuezhi Cang

Graduate Research Theses & Dissertations

Although Mars is cold and dry today, many lines of evidence suggest that ancient Mars had large amount of water and surface fluvial processes. However, climate modelers have encountered difficulties in modeling such early warm and wet conditions with an above freezing temperature, mainly due to the Martian orbit being further away from the Sun and the faintness of the young Sun. The main purpose of this dissertation is to test the ancient Martian climate hypotheses by investigating the spatial pattern of valley network (VN) properties that can survive post-formational modification (i.e., the robust characteristics) and by analogizing the Earth …