Earth Sciences Commons^™

Seasonal H2o And Co2 Ice Cycles At The Mars Phoenix Landing Site: 1. Prelanding Crism And Hirise Observations, Selby Cull, Raymond E. Arvidson, Michael Mellon, Sandra Wiseman, Roger Clark, Timothy Titus, Richard V. Morris, Patrick Mcguire

Geology Faculty Research and Scholarship

The condensation, evolution, and sublimation of seasonal water and carbon dioxide ices were characterized at the Mars Phoenix landing site from Martian northern midsummer to midspring (L_s ∼ 142° – L_s ∼ 60°) for the year prior to the Phoenix landing on 25 May 2008. Ice relative abundances and grain sizes were estimated using data from the Compact Reconnaissance Imaging Spectrometer for Mars and High Resolution Imaging Science Experiment aboard Mars Reconnaissance Orbiter and a nonlinear mixing model. Water ice first appeared at the Phoenix landing site during the afternoon in late summer (L_s ∼ 167°) as …

Seasonal Ice Cycle At The Mars Phoenix Landing Site: 2. Postlanding Crism And Ground Observations, Selby Cull, R. E. Arvidson, R. V. Morris, M. Wolff, M. T. Mellon, M. T. Lemmon

Geology Faculty Research and Scholarship

The combination of ground observations from the Mars Phoenix Lander and orbital data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) provided a detailed view of the formation of late summer surface water ice at the landing site and surrounding regions. CRISM observations of the landing site during and immediately after Phoenix operations were analyzed to track the seasonal and diurnal ice cycles during the late spring to late summer, and a nonlinear mixing model was used to estimate grain sizes and relative abundances of water ice and dust. The surface around the Phoenix landing site was ice-free from …

Effects Of Drought On Avian Community Structure, Thomas P. Albright, Anna M. Pidgeon, Chadwick D. Rittenhouse, Murray K. Clayton, Curtis H. Flather, Patrick D. Culbert, Brian D. Wardlows, Volker C. Radeloff

National Drought Mitigation Center: Faculty Publications

Droughts are expected to become more frequent under global climate change. Avifauna depend on precipitation for hydration, cover, and food. While there are indications that avian communities respond negatively to drought, little is known about the response of birds with differing functional and behavioral traits, what time periods and indicators of drought are most relevant, or how response varies geographically at broad spatial scales. Our goals were thus to determine (1) how avian abundance and species richness are related to drought, (2) whether community variations are more related to vegetation vigor or precipitation deviations and at what time periods relationships …

The Distribution And Origins Of Acid Groundwaters In The South West Agricultural Area, Adam Lillicrap, Richard J. George Dr

Resource management technical reports

No abstract provided.

Geologic Map Of The Nez Perce Drainage Basin, Southwestern Montana, Rose Aimee Feinstein

Inquiry: The University of Arkansas Undergraduate Research Journal

A geologic map of the Nez Perce drainage basin in southwestern Montana offers an understanding of the developing paleotopography of the area following the Laramide orogeny, ca. 65 ma. In this project, a small drainage basin was studied in detail, focusing on the geomorphology, structure, lithology, and ages of the various rock units. Based on the results of these studies and the relationships found among four major gravel units mapped within the basin, the basin development was approximated. The youngest unit is a fine-grained (mean diameter = 8.23 cm) channel deposit within Nez Perce Creek, sourced from within the basin, …

A Two-Dimensional, Linear–Elastic Model To Explain Radial Extensional Fractures, Pantheon Fossae, Caloris Basin, Mercury, Brianne Mcdonough

Undergraduate Review

In this study, two-dimensional linear elasticity theory is used to model the lithospheric stress field that produces radial extensional fractures observed at Pantheon Fossae in the Caloris Basin of Mercury. These fractures were imaged by the MESSENGER mission flyby of Mercury on January 14, 2008 and show radial fractures extending outward from a 40-kilometer impact crater named Apollodorus. Recent studies have proposed several different mechanisms to explain these fractures, including magmatic processes, central basin uplift, and stresses produced by the formation of the impact crater itself.

Constructing A Flash Flood Climatology Of The Appalachian Mountains: Comparison Of Eastern Kentucky And West Virginia Summer Time Rain Events, Jane Marie Wix

Mahurin Honors College Capstone Experience/Thesis Projects

The Appalachian Mountains are subject to flash floods due to interactions between complex terrain and frequent rainfall. Previous studies have shown that a number of environmental factors can trigger flash floods, which can leave behind a variety of outcomes. However, there is a lack of research concerning flash floods in the Appalachian region. This study addresses these concerns by examining summer (June-August) rainfall frequency and intensity in connection with flash floods in the Appalachian region of eastern Kentucky and West Virginia during 1995-2005. Flash floods were identified using the National Climatic Data Center’s (NCDC) Storm Database. Radar estimated rainfall data …

Regional Vs. Local Impact Of Wind On Glaciers In The Andes Mountains, Derek Ferris

Undergraduate Review

Northern Peru will face critical water resource issues in the near future as permanent ice in the Andes Mountains continues to rapidly melt. Ironically, the melt-water from these glaciers supports the culture of 100s of thousands of people living at lower elevations, particularly during the dry season, and predictions suggest some glaciers may be gone in less than 100 years. The impact of local warming of “U” shaped valleys running down the dryer western slope of the Andes range is largely disregarded in current climate model predictions because of the complexity of simulating the complex topography. Studies that compare the …

An Inventory And Condition Survey Of The Western Australian Part Of The Nullarbor Region, Peter-Jon A. Waddell, A K. Gardner, P Hennig

Technical Bulletins

The inventory and condition survey of the Western Australian part of the Nullarbor region, undertaken by the Department of Agriculture and Food, Western Australia (DAFWA) between 2005 and 2007, describes and maps the natural resources of the region. This survey report provides a baseline record of the existence and condition of the area's natural resources, to assist with the planning and implementation of land management practices. The report identified and described the condition of soils, landforms, vegetation, habitat, ecosystems, and declared plants and animals. It also assessed the impact of pastoralism and made land management recommendations. The Nullarbor region has …

Forest Analysis Of The Gordon Natural Area Focusing On Carbon Stock, Forest Structure, And Forest Composition, R. Dicce, D. Drake, D. Mackey, P. Avery

Forest Carbon Storage Study Documents

No abstract provided.

Geology Of The Gordon Natural Area: A Service-Learning Investigation By Students In Ess 405, Petrology, Fall 2009, Leeann Srogi

Gordon Natural Area Geology Studies Documents

No abstract provided.

Holocene Landscape Response To Seasonality Of Storms In The Mojave Desert, David M. Miller, Kevin M. Schmidt, Shannon A. Mahan, John P. Mcgeehin, Lewis A. Owen, John A. Barron, Frank Lehmkuhl, Rene Lohrer

United States Geological Survey: Staff Publications

New optically stimulated and radiocarbon ages for alluvial fan and lake deposits in the Mojave Desert are presented, which greatly improves the temporal resolution of surface processes. The new Mojave Desert climate-landscape record is particularly detailed for the late Holocene. Evidence from ephemeral lake deposits and landforms indicates times of sustained stream flow during a wet interval of the latter part of the Medieval Warm Period at ca. AD 1290 and during the Little Ice Age at ca. AD 1650. The former lakes postdate megadroughts of the Medieval Warm Period, whereas the latter match the Maunder Minimum of the Little …

Temporal And Spatial Variations In Freshwater 14C Reservoir Effects: Lake Mývatn, Northern Iceland, Philippa L. Ascough, G. T. Cook, M. J. Church, E. Dunbar, Á. Einarsson, Thomas H. Mcgovern, A. J. Dugmore, Sophia Perdikaris, H. Hastie, A. Friðriksson, H. Gestsdóttir

School of Global Integrative Studies: Faculty Publications

Lake Mývatn is an interior highland lake in northern Iceland that forms a unique ecosystem of international scientific importance and is surrounded by a landscape rich in archaeological and paleoenvironmental sites. A significant freshwater reservoir effect (FRE) has been identified in carbon from the lake at some Viking (about AD 870–1000) archaeological sites in the wider region (Mývatnssveit). Previous accelerator mass spectrometry (AMS) measurements indicated this FRE was about 1500–1900 ¹⁴C yr. Here, we present the results of a study using stable isotope and ¹⁴C measurements to quantify the Mývatn FRE for both the Viking and modern periods. …

Correlation Between Normalized Ddifference Vvegetation Index And Malaria In A Subtropical Rain Forest Undergoing Rapid Anthropogenic Alteration, Nicole M. Wayant, Diego Maldonado, Antonieta Rojas De Arias, Blanca Cousino, Douglas G. Goodin

Center for Advanced Land Management Information Technologies: Publications

Time-series of coarse-resolution greenness values derived through remote sensing have been used as a surrogate environmental variable to help monitor and predict occurrences of a number of vector-borne and zoonotic diseases, including malaria. Often, relationships between a remotely-sensed index of greenness, e.g. the normalized difference vegetation index (NDVI), and disease occurrence are established using temporal correlation analysis. However, the strength of these correlations can vary depending on type and change of land cover during the period of record as well as inter-annual variations in the climate drivers (precipitation, temperature) that control the NDVI values. In this paper, the correlation between …

Geochemical And Mineralogical Evidence For Sahara And Sahel Dust Additions To Quaternary Soils On Lanzarote, Eastern Canary Islands, Spain, Daniel R. Muhs, James Budahn, Gary Skipp, Joseph M. Prospero, Deanna Patterson, E. Arthur Bettis Iii

United States Geological Survey: Staff Publications

Africa is the most important source of dust in the world today, and dust storms are frequent on the nearby Canary Islands. Previous workers have inferred that the Sahara is the most important source of dust to Canary Islands soils, with little contribution from the Sahel region. Soils overlying a late Quaternary basalt flow on Lanzarote, Canary Islands, contain, in addition to volcanic minerals, quartz and mica, exotic to the island!s bedrock. Kaolinite in the soils also likely has an exotic origin. Trace-element geochemistry shows that the soils are derived from varying proportions of locally derived basalt and African dust. …

The Influence Of Nutrients And Physical Habitat In Regulating Algal Biomass In Agricultural Streams, Mark D. Munn, Jeffrey Frey, Anthony Tesoriero

United States Geological Survey: Water Reports and Publications

This study examined the relative influence of nutrients (nitrogen and phosphorus) and habitat on algal biomass in five agricultural regions of the United States. Sites were selected to capture a range of nutrient conditions, with 136 sites distributed over five study areas. Samples were collected in either 2003 or 2004, and analyzed for nutrients (nitrogen and phosphorous) and algal biomass (chlorophyll a). Chlorophyll a was measured in three types of samples, fine-grained benthic material (CHLFG), coarse-grained stable substrate as in rock or wood (CHLCG), and water column (CHLS). Stream and riparian habitat were characterized at each site. TP ranged from …

Mercury Concentrations In Fish From A Sierra Nevada Foothill Reservoir Located Downstream From Historic Gold-Mining Operations, Michael K. Saiki, Barbara A. Martin, Thomas W. May, Charles N. Alpers

United States Geological Survey: Staff Publications

This study examined mercury concentrations in whole fish from Camp Far West Reservoir, an 830-ha reservoir in northern California, USA, located downstream from lands mined for gold during and following the Gold Rush of 1848–1864. Total mercury (reported as dry weight concentrations) was highest in spotted bass (mean, 0.93 μg/g; range, 0.16–4.41 μg/g) and lower in bluegill (mean, 0.45 μg/g; range, 0.22– 1.96 μg/g) and threadfin shad (0.44 μg/g; range, 0.21–1.34 μg/g). Spatial patterns for mercury in fish indicated high concentrations upstream in the Bear River arm and generally lower concentrations elsewhere, including downstream near the dam. These findings coincided …

Development And Application Of A Pollen-Based Paleohydrologic Reconstruction From The Lower Roanoke River Basin, North Carolina, Usa, Debra Willard, Christopher Bernhardt, Roger Brown, Bryan Landacre, Philip A. Townsend

United States Geological Survey: Staff Publications

We used pollen assemblages to reconstruct late-Holocene paleohydrologic patterns in floodplain deposits from the lower Roanoke River basin (North Carolina, southeastern USA). Using 120 surface samples from 38 transects, we documented statistical relationships between pollen assemblages, vegetation, and landforms. Backswamp pollen assemblages (long hydroperiods) are dominated by Nyssa (tupelo) and Taxodium (cypress) and have high pollen concentrations. Sediments from elevated levees and seasonally flooded forests (shorter hydroperiods) are characterized by dominant Pinus (pine) pollen, variable abundance of hardwood taxa, and low pollen concentrations. We apply the calibration data set to interpret past vegetation and paleohydrology. Pollen from a radiocarbon-dated sediment …

Droughtscape, Winter 2010, Kelly Smith

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

USDM Forum Highlights

Drought Likely to Ease

Research Shows Birds Vulnerable to Drought

Drought Recedes in 2009

CA, TX Suffer Impacts from Ongoing Drought

NDMC Wishes Ryu Well

Conferees Pick SPI for Global Drought Index

Crustal Thickness Of The Marie Byrd Land Dome And Its Implications, Joshua Svaldi

Undergraduate Honors Theses

This study focuses on the crustal thickness of the Marie Byrd Land Dome (MBLD) in West Antarctica, which is a region of high elevation in proximity to a zone of extension and crustal thinning. We use the H-K receiver-function stacking method developed by Zhu and Kanamori (2000) to analyze the incoming seismic waves of tcleseismic events. The aim of the project is to determine whether or not the MLBD is in isostatic equilibrium. Values for crustal thickness at the Mt. Patterson site, along the western extremity of MBLD, are 28-31 km, while theoretical calculations have yielded a thickness of 33.5 …

Landscapes And Soils Of The Northam District, D N. Sawkins, Department Of Agriculture And Food

Bulletins 4000 -

The publication aims to provide readers with the principles underlying the formation of local landscapes and soils, and the ability to identify landscapes and their associated soils.

Combined Use Of Frequency-Domain Electromagnetic And Electrical Resistivity Surveys To Delineate Near-Lake Groundwater Flow In The Semi-Arid Nebraska Sand Hills, Usa, John T. Ong, John W. Lane Jr., Vitaly A. Zlotnik, Todd Halihan, Eric A. White

Department of Earth and Atmospheric Sciences: Faculty Publications

A frequency-domain electromagnetic (FDEM) survey can be used to select locations for the more quantitative and labor-intensive electrical resistivity surveys. The FDEM survey rapidly characterized the groundwaterflow directions and configured the saline plumes caused by evaporation from several groundwater-dominated lakes in the Nebraska Sand Hills, USA. The FDEM instrument was mounted on a fiberglass cart and towed by an all-terrain vehicle, covering about 25km/day. Around the saline lakes, areas with high electrical conductivity are consistent with the regional and local groundwater flow directions. The efficacy of this geophysical approach is attributed to: the high contrast in electrical conductivity between various …

Salinity Dynamics Of Discharge Lakes In Dune Environments: Conceptual Model, Vitaly A. Zlotnik, Neville I. Robinson, Craig T. Simmons

Department of Earth and Atmospheric Sciences: Faculty Publications

Lakes of varying salinity are ubiquitous in dune environments with semiarid climates. Often these lakes become solute traps due to specific groundwater flow conditions. Over geological time after emergence of such lakes, the groundwater flow and mass transport processes lead to accumulation of solutes. This salinity increase can result in mineral deposition and free convection from lakes. However, high solute concentrations in these lakes are often not observed. We propose a conceptual model that estimates the lake salinity dynamics and yields concentration profiles beneath the lakes over centennial and millennial scales. Unlike previous approaches, a simple mathematical model is proposed …

Effects Of Irrigated Agroecosystems: 1. Quantity Of Soil Water And Groundwater In The Southern High Plains, Texas, B. R. Scanlon, R. C. Reedy, J. B. Gates

Department of Earth and Atmospheric Sciences: Faculty Publications

Although irrigated agriculture is the primary consumer of global groundwater resources, information on recharge rates and sustainable irrigation is limited. The study objective was to fingerprint irrigation return flow to quantify percolation/recharge and to estimate sustainable irrigation levels. This paper focuses on water quantity; a companion paper addresses water quality. Soil samples from 13 boreholes drilled beneath irrigated agroecosystems in the southern High Plains were analyzed for matric potential and waterextractable Cl and NO₃. Unsaturated zone pore water beneath irrigated agroecosystems can be fingerprinted by higher matric potentials (wetter soils, median mp: −40 m) and higher NO_{3 …}

Planning The Future Of Geocybereducation, Jeffrey G. Ryan, Susan Eriksson

Geology Faculty Publications

No abstract provided.

Trace Element Geochemistry In Groundwater Flow Systems, Stephanie Scholten Willis

Earth & Environmental Sciences Dissertations - Archive

This research focuses on trace element geochemistry in three groundwater flow systems: the Carrizo Sand, the Upper Floridan, and the Aquia aquifers. The focus is threefold: (i) studying the geochemical behavior, concentrations, and fractionation patterns of rare earth elements (REEs) along two flow paths by examination of both groundwater and sediment samples, (ii) investigating the behavior of arsenic (As) and antimony (Sb) and comparing these data to reveal the biogeochemical processes affecting As and Sb concentrations and speciation as well as determining correlations between As and Sb concentrations, and (iii) formulating adsorption isotherms to demonstrate the adsorption capacity of As …

Verrucomicrobia: A Model Phylum To Study The Effects Of Deforestation On Microbial Diversity In Amazon Forest, Kshitij Ranjan

Earth & Environmental Sciences Theses - Archive

The Amazon rainforest is known for having a very high diversity of plants and animals. However, it is one of the least understood ecosystems regarding microbial diversity. Microorganisms are important for the ecological balance of any ecosystem and play important role in various biogeochemical cycles. As the Amazon rainforest undergoes to rapid deforestation, loss of its biodiversity is expected. This research aims to determine the effects of deforestation on the soil microbial diversity of the Amazon forest. Toward this, we selected the phylum Verrucomicrobia as a model for observing changes in the microbial structure of rainforest soils. Samples were collected …

Growth And Toxicity Of Prymnesium Parvum In Long-Term Cultures At Low Temperature And Salinity, Xianzi He

Earth & Environmental Sciences Theses - Archive

There is a paradox reported concerning observations of toxic blooms of Prymnesium parvum in winter in Texas (USA), and its growth performance in the laboratlry. Culture experiments indicate relatively high optimum temperature and salinity for growth, conditions different from those ofwinter in Texas. Because previous laboratory experiments were of short duration, it was suggested that long-term culturing of many generations could allow physiological and epigenetic changes, as well as natural selection to take place, leading to improved growth performance at low temperature and salinity. In this study, the growth and toxicity of P. parvum was investigated under relatively low temperature …

Landscapes And Soils Of The Narrogin District, D N. Sawkins

Bulletins 4000 -

The publication aims to provide readers with the principles underlying the formation of local landscapes and soils, and the ability to identify landscapes and their associated soils.

Tree Rings And Earthquakes, Matthew F. Bekker

Wasatch Dendroclimatology Research

The lithosphere, earth’s rigid outer shell comprising crust and upper mantle rock, is broken into about 14 tectonic plates (Christopherson 2009) that move a few centimeters per year over superheated, pliable rock underneath. Forces within earth’s interior push, pull and twist the plates in different directions, producing three types of plate boundaries: convergent (colliding with one another), divergent (moving away from one another) and transform (sliding past one another). Earthquakes occur when plates become locked together, building strain between and within them that is suddenly released, sending a burst of seismic waves that cause shaking and displacement of the surface. …