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Oligocene Deep Water Export From The North Atlantic And The Development Of The Antarctic Circumpolar Current Examined With Neodymium Isotopes, Howie Scher, Ellen E. Martin Jan 2008

Oligocene Deep Water Export From The North Atlantic And The Development Of The Antarctic Circumpolar Current Examined With Neodymium Isotopes, Howie Scher, Ellen E. Martin

Faculty Publications

Neodymium (Nd) isotopes were measured on 181 samples of fossil fish teeth recovered from Oligocene toMiocene sections at Ocean Drilling Program Site 1090 (3700 m water depth) on Agulhas Ridge in the Atlanticsector of the Southern Ocean. A long-term decreasing trend toward less radiogenic Nd isotope compositionsdominates the record. This trend is interrupted by shifts toward more radiogenic compositions near the early/lateOligocene boundary and the Oligocene/Miocene boundary. Overall, eNd values at Agulhas Ridge are moreradiogenic than at other Atlantic locations, and are similar to those at Indian Ocean locations. The pattern ofvariability is remarkably similar to Nd isotope results from …


The Dynamic Evolutionary History Of The Bananaquit (Coereba Flaveola) In The Caribbean Revealed By A Multigene Analysis, Eva Bellemain, Eldredge Bermingham, Robert Ricklefs Jan 2008

The Dynamic Evolutionary History Of The Bananaquit (Coereba Flaveola) In The Caribbean Revealed By A Multigene Analysis, Eva Bellemain, Eldredge Bermingham, Robert Ricklefs

Biology Department Faculty Works

BackgroundThe bananaquit (Coereba flaveola) is a small nectivorous and frugivorous emberizine bird (order Passeriformes) that is an abundant resident throughout the Caribbean region. We used multi-gene analyses to investigate the evolutionary history of this species throughout its distribution in the West Indies and in South and Middle America. We sequenced six mitochondrial genes (3744 base pairs) and three nuclear genes (2049 base pairs) for forty-four bananaquits and three outgroup species. We infer the ancestral area of the present-day bananaquit populations, report on the species' phylogenetic, biogeographic and evolutionary history, and propose scenarios for its diversification and range expansion.ResultsPhylogenetic concordance between …


Sampling Of Malodorous Compounds In Air Using Stir Bar Sorbtive Extraction, John H. Loughrin, Nanh Lovanh, Arturo I. Quintanar, Rezaul Mahmood Jan 2008

Sampling Of Malodorous Compounds In Air Using Stir Bar Sorbtive Extraction, John H. Loughrin, Nanh Lovanh, Arturo I. Quintanar, Rezaul Mahmood

High Plains Regional Climate Center: Staff Publications

Twisters, (poly)‐dimethylsiloxane‐coated magnetic stir bars, were used to measure compounds typical of swine manure malodor in air. In initial experiments, a time to achieve equilibrium was determined by preloading the stir bars with ten compounds with a range of volatilities and polarities and then monitoring their loss. The rate of loss was dependent on compound volatility, and the time for equilibrium to be attained varied widely, from 22 min for phenol to 210 min for skatole. To test whether the Twisters would respond linearly over a range of concentrations, the stir bars were placed in vented jars with solutions of …


Distribution And Environmental Limitations Of An Amphibian Pathogen In The Rocky Mountains, Usa, Erin Muths, David S. Pilliod, Lauren J. Livo Jan 2008

Distribution And Environmental Limitations Of An Amphibian Pathogen In The Rocky Mountains, Usa, Erin Muths, David S. Pilliod, Lauren J. Livo

United States Geological Survey: Staff Publications

Amphibian populations continue to be imperiled by the chytrid fungus (Batrachochytrium dendrobatidis). Understanding where B. dendrobatidis (Bd) occurs and how it may be limited by environmental factors is critical to our ability to effectively conserve the amphibians affected by Bd. We sampled 1247 amphibians (boreal toads and surrogates) at 261 boreal toad (Bufo boreas) breeding sites (97 clusters) along an 11° latitudinal gradient in the Rocky Mountains to determine the distribution of B. dendrobatidis and examine environmental factors, such as temperature and elevation, that might affect its distribution. The fungus was detected at …


Paleoclimatic Significance Of Chemical Weathering In Loess-Derived Paleosols Of Subarctic Central Alaska, Daniel R. Muhs, Thomas A. Ager, Gary Skipp, Jossh Beann, James Budahn, John P. Mcgeehin Jan 2008

Paleoclimatic Significance Of Chemical Weathering In Loess-Derived Paleosols Of Subarctic Central Alaska, Daniel R. Muhs, Thomas A. Ager, Gary Skipp, Jossh Beann, James Budahn, John P. Mcgeehin

United States Geological Survey: Staff Publications

Chemical weathering in soils has not been studied extensively in high-latitude regions. Loess sequences with modern soils and paleosols are present in much of subarctic Alaska, and allow an assessment of present and past chemical weathering. Five sections were studied in detail in the Fairbanks, Alaska, area. Paleosols likely date to mid-Pleistocene interglacials, the last interglacial, and early-to-mid- Wisconsin interstadials. Ratios of mobile (Na, Ca, Mg, Si) to immobile (Ti or Zr) elements indicate that modern soils and most interstadial and interglacial paleosols are characterized by significant chemical weathering. Na2O/TiO2 is lower in modern soils and most …


Integrated Modelling Frameworks For Environmental Assessment And Decision Support, A. E. Rizzoli, G. Leavesley, J. C. Ascough Ii, R. M. Argent, I. N. Athanasiadis, V. Brilhante, F. H. A. Claeys, O. David, M. Donatelli, P. Gijsbers, D. Havlik, A. Kassahun, P. Krause, N. W. T. Quinn, H. Scholten, R. S. Sojda, F. Villa Jan 2008

Integrated Modelling Frameworks For Environmental Assessment And Decision Support, A. E. Rizzoli, G. Leavesley, J. C. Ascough Ii, R. M. Argent, I. N. Athanasiadis, V. Brilhante, F. H. A. Claeys, O. David, M. Donatelli, P. Gijsbers, D. Havlik, A. Kassahun, P. Krause, N. W. T. Quinn, H. Scholten, R. S. Sojda, F. Villa

United States Geological Survey: Staff Publications

As argued in Chapter 1, modern management of environmental resources defines problems from a holistic and integrated perspective, thereby imposing strong requirements on Environmental Decision Support Systems (EDSSs) and Integrated Assessment Tools (IATs). These systems and tools tend to be increasingly complex in terms of software architecture and computational power in order to cope with the type of problems they must solve. For instance, the discipline of Integrated Assessment (IA) needs tools that arc able to span a wide range of disciplines, from socio-economics to ecology to hydrology. Such tools must support a wide range of methodologies and techniques like …


In Memoriam Jean Philippe Marcoux, A.M. Celal Şengör Jan 2008

In Memoriam Jean Philippe Marcoux, A.M. Celal Şengör

Turkish Journal of Earth Sciences

No abstract provided.


Holocene Sediment Magnetic Properties Along A Transect From Isafjardardjup To Djupall, Northwest Iceland, Sarah M. Principato, J.T. Andrews, J. Hardardottir, J.S. Stoner Jan 2008

Holocene Sediment Magnetic Properties Along A Transect From Isafjardardjup To Djupall, Northwest Iceland, Sarah M. Principato, J.T. Andrews, J. Hardardottir, J.S. Stoner

Environmental Studies Faculty Publications

Holocene changes in terrestrial provenance and processes of sediment transport and deposition are tracked along a fjord-to-shelf transect adjacent to Vestfirdir, Iceland, using the magnetic properties ofmarine sediments.Magnetic susceptibility (MS) profiles of 10 cores (gravity and piston) were obtained onboard using a Bartington MS loop. Remanent magnetizations were measured at 1-cm intervals from u-channel samples taken from six cores on a cryogenic magnetometer. Between six and nine alternating field demagnetization steps were used to isolate the characteristic magnetization directions. The chronologies of the cores used in this study were determined from AMS14 C dates on mollusks and foraminifera and contrained …


Wind Scour Of Navajo Sandstone At The Wave (Central Colorado Plateau, U.S.A.), David B. Loope, Winston M. Seiler, Joseph A. Mason, Marjorie A. Chan Jan 2008

Wind Scour Of Navajo Sandstone At The Wave (Central Colorado Plateau, U.S.A.), David B. Loope, Winston M. Seiler, Joseph A. Mason, Marjorie A. Chan

Department of Earth and Atmospheric Sciences: Faculty Publications

At the Wave, a photogenic landform on the Utah–Arizona border, modern, southwesterly, sand-carrying winds abrade the Navajo Sandstone. Abundant trains of centimeter-scale, transverse, upwind-facing treads and risers cut sedimentary structures at a high angle. Central to the formation of these erosional steps are crusts produced by microbes lying just beneath exposed sandstone surfaces. Treads and risers are present on the walls of smoothly curved troughs at the Wave, on the walls of nearby circular scour pits, and on bedrock domes found at the center of scour pits. Because of their locations and orientations, the large-scale troughs and scour pits could …


Locating Suitable Habitats For West Nile Virus-Infected Mosquitoes Through Association Of Environmental Characteristics With Infected Mosquito Locations: A Case Study In Shelby County, Tennessee, Esra Ozdenerol, Elzbieta Bialkowska-Jelinska, Gregory N. Taff Jan 2008

Locating Suitable Habitats For West Nile Virus-Infected Mosquitoes Through Association Of Environmental Characteristics With Infected Mosquito Locations: A Case Study In Shelby County, Tennessee, Esra Ozdenerol, Elzbieta Bialkowska-Jelinska, Gregory N. Taff

School of Geosciences Student Publications

Background: Since its first detection in 2001, West Nile Virus (WNV) poses a significant health risk for residents of Shelby County in Tennessee. This situation forced public health officials to adopt efficient methods for monitoring disease spread and predicting future outbreaks. Analyses that use environmental variables to find suitable habitats for WNV-infected mosquitoes have the potential to support these efforts. Using the Mahalanobis Distance statistic, we identified areas of Shelby County that are ecologically most suitable for sustaining WNV, based on similarity of environmental characteristics to areas where WNV was found. The environmental characteristics in this study were based on …


Not Your Father’S Border: An Examination Of The Border In Northern Ireland And Its Relevance To The Global Change In The Importance Of World Borders, Aaron Patterson Jan 2008

Not Your Father’S Border: An Examination Of The Border In Northern Ireland And Its Relevance To The Global Change In The Importance Of World Borders, Aaron Patterson

Theses, Dissertations and Capstones

Humanity has long maintained barriers separating specific entities from others. Ranging from cultural, religious, financial, and racial differences among a few others, the reasoning behind borders has remained a purely human endeavor. But our current golden age of technology has somewhat shrunk, or at least reassessed the necessity for borders. The boundaries of today, while many remain in the same locations as in the past, are vastly different from the borders created by previous generations. Globalization, a relatively new term, has made communication simple and fast. The noticeable result has been, of course, better communication between locations, and thus easing …


Volcanic Activity: Processing Of Observation And Remote Sensing Data (Vapor), Mark Wylie Jan 2008

Volcanic Activity: Processing Of Observation And Remote Sensing Data (Vapor), Mark Wylie

Reports

The World Bank makes a very clear distinction between disasters and natural phenomena. Natural phenomena are events like volcanic eruptions. A disaster only occurs when the ability of the community to cope with natural phenomenon has been surpassed, causing widespread human, material, economic or environmental losses. By these definitions, volcanic eruptions do not have to lead to disasters. On November 13, 1985, the second most deadly eruption of the twentieth century occurred in Colombia. Within a few hours of the eruption of the Nevado del Ruiz volcano, 23,000 people were dead because no infrastructure existed to respond to such an …


Historic Resource Study: Agate Fossil Beds National Monument, Gail Evans-Hatch Jan 2008

Historic Resource Study: Agate Fossil Beds National Monument, Gail Evans-Hatch

United States National Park Service: Publications

As steward of many of the United States' most important cultural and natural resources, the National Park Service (NPS) is required to create background documents along with specific plans aimed at managing and protecting these resources for the enjoyment of present and future generations. An important aspect of managing cultural landscapes requires knowing the past of those landscapes. A historic resource study (HRS) project involves researching and presenting the history of a park. A HRS also attempts to identify and evaluate the importance of all cultural resources within that park. Researching and presenting the broader historical context of a park …


Intelligent Environmental Decision Support Systems, M. Sànchez-Marrè, K. Gibert, R. S. Sojda, J. P. Steyer, P. Struss, I. Rodríguez-Roda, J. Comas, V. Brilhante, E. A. Roehl Jan 2008

Intelligent Environmental Decision Support Systems, M. Sànchez-Marrè, K. Gibert, R. S. Sojda, J. P. Steyer, P. Struss, I. Rodríguez-Roda, J. Comas, V. Brilhante, E. A. Roehl

United States Geological Survey: Staff Publications

Introduction
Complexity of environmental systems
New tools for a new paradigm
Intelligent Environmental Decision Support Systems (IEDSS)
IEDSS development
About Uncertainty Management
Temporal Reasoning
Featuring the problem
Approaches to temporal reasoning
Case-based reasoning for temporal reasoning
Geographic Information and Spatial Reasoning
Understanding spatial reasoning
Kriging and variants
Representing change/time steps/feedback loops
Middleware. blackboards and communication protocols
Multiagent systems
Evaluation of IEDSS and Benchmarking
Benchmarking
Conclusions and Future Trends


Influence Of Fipronil Compounds And Rice-Cultivation Land-Use Intensity On Macroinvertebrate Communities In Streams Of Southwestern Louisiana, Usa, Scott V. Mize, Stephen D. Porter, Dennis K. Demcheck Jan 2008

Influence Of Fipronil Compounds And Rice-Cultivation Land-Use Intensity On Macroinvertebrate Communities In Streams Of Southwestern Louisiana, Usa, Scott V. Mize, Stephen D. Porter, Dennis K. Demcheck

United States Geological Survey: Staff Publications

Laboratory tests of fipronil and its degradation products have revealed acute lethal toxicity at very low concentrations (LC50) of <0.5 μg/L to selected aquatic macroinvertebrates. In streams draining basins with intensive rice cultivation in southwestern Louisiana, USA, concentrations of fipronil compounds were an order of magnitude larger than the LC50. The abundance (p=-0.64; p=0.015) and taxa richness (r2=0.515, p<0.005) of macroinvertebrate communities declined significantly with increases in concentrations of fipronil compounds and rice-cultivation land-use intensity. Macroinvertebrate community tolerance scores increased linearly (r2=0.442, p < 0.005) with increases in the percentage of rice cultivation in the basins, indicating increasingly degraded stream conditions. Similarly, macroinvertebrate community-tolerance scores increased rapidly as fipronil concentrations approached about 1 μg/L. Pesticide toxicity index determinations indicated that aquatic macroinvertebrates respond to a gradient of fipronil compounds in water although stream size and habitat cannot be ruled out as contributing influences.


Post-Miocene Deformation In The South Of The Galatean Volcanic Province, Nw Of Central Anatolia (Turkey), Bora Rojay, A. Karaca Jan 2008

Post-Miocene Deformation In The South Of The Galatean Volcanic Province, Nw Of Central Anatolia (Turkey), Bora Rojay, A. Karaca

Turkish Journal of Earth Sciences

Central Anatolia, located on the immense Alpine-Himalayan orogenic belt, has a complicated neotectonic evolution, and NE-SW-trending Neogene horsts-graben systems that rejuvenate pre-existing palaeostructures are among the most important structures which help us understand the tectonic evolution of Central Anatolia. Post-Miocene deformational studies were carried out in Miocene-Quaternary sequences situated at the southeastern margin of the Galatean Volcanic Province (NW of Central Anatolia, Turkey) in order to understand the deformational history of Central Anatolia. The structural analyses were based on bedding attitude data and fault plane slip data. Fold analysis in Miocene units gave an asymmetrical fold axis trending 046ºN. Although …


Stable Isotopes In Early Eocene Mammals As Indicators Of Forest Canopy Structure And Resource Partitioning, Ross Secord, Scott L. Wing, Amy Chew Jan 2008

Stable Isotopes In Early Eocene Mammals As Indicators Of Forest Canopy Structure And Resource Partitioning, Ross Secord, Scott L. Wing, Amy Chew

Department of Earth and Atmospheric Sciences: Faculty Publications

The three dimensional structure of vegetation is an important component of ecosystems, yet it is difficult to reconstruct from the fossil record. Forests or woodlands prevailed at mid-latitudes in North America during the early Eocene but tree spacing and canopy structure are uncertain. Here we use stable carbon isotope values (δ13C) in early Eocene mammalian faunas to infer canopy structure. We compare δ13C values in two diverse fossil assemblages from the central Bighorn Basin to values predicted for mammals in a variety of open and closed habitats, based on modern floras and faunas. We conclude that …


Iron Ooid Beds Of The Carolinefjellet Formation, Spitsbergen, Norway, Jeremy Mutrux, Harmon D. Maher Jr., Robert Duncan Shuster Jan 2008

Iron Ooid Beds Of The Carolinefjellet Formation, Spitsbergen, Norway, Jeremy Mutrux, Harmon D. Maher Jr., Robert Duncan Shuster

Geography and Geology Faculty Publications

Iron ooid beds are unusual deposits that have been linked to greenhouse conditions and the transgressive flooding of shallow shelves, and which were globally prevalent during certain periods. Within the marine, Aptian-Albian, Carolinefjellet Formation of Spitsbergen, chamosite ooids have been found within distinctive sandstone beds at six localities, and at a consistent stratigraphic position within the basal Dalkjegla Member. Distinctive characteristics include the iron ooids themselves, a coarser grain size, intercalation with silty siderites, grading, cross-beds indicating offshore or longshore transport, and a lack of burrowing. The enclosing sands display planar and hummocky crossstratification and abundant oscillation ripple marks, and …


Geology Of Rum Cay, Bahamas: A Field Trip Guide, John E. Mylroie, James L. Carew, H. Allen Curran, Jonathan B. Martin, Thomas A. Rothfus, Neil E. Sealey, Fredrick D. Siewers Jan 2008

Geology Of Rum Cay, Bahamas: A Field Trip Guide, John E. Mylroie, James L. Carew, H. Allen Curran, Jonathan B. Martin, Thomas A. Rothfus, Neil E. Sealey, Fredrick D. Siewers

Geosciences: Faculty Publications

See other Smith authored Field Trip Guides of Gerace Research Centre.


Glacial Deposits, Vol. 36, 2007-2008, Department Of Geography-Geology Jan 2008

Glacial Deposits, Vol. 36, 2007-2008, Department Of Geography-Geology

Glacial Deposits

Newsletter of the Department of Geography-Geology


On The Origin And Age Of The Arıburnu Beachrock, Gelibolu Peninsula, Turkey, Ahmet Evren Ergi̇nal, Nafi̇ye Kiyak Güneç, Mustafa Bozcu, Ahmet Ertek, Hakan Güngüneş, Ali̇ Sungur, Gülen Türker Jan 2008

On The Origin And Age Of The Arıburnu Beachrock, Gelibolu Peninsula, Turkey, Ahmet Evren Ergi̇nal, Nafi̇ye Kiyak Güneç, Mustafa Bozcu, Ahmet Ertek, Hakan Güngüneş, Ali̇ Sungur, Gülen Türker

Turkish Journal of Earth Sciences

The beachrock formation on the Arıburnu coast situated in the Gelibolu Peninsula has been studied by field observation, thin-section interpretation, physicochemical analyses including ICP-AES and SEM/EDS, and OSL dating. These analyses reveal the presence of different amounts of major (Si, Ca, Mg, K, Fe, Al and Na) and trace elements within the beachrock cement with Si (36.2%) and Ca (32.68%) dominating the overall composition. Beachrocks composed of highly-fractured and friable beds reach a total thickness of 80 cm extending from +60 cm at the uppermost level down to -1 m at their most seaward extent and grade from conglomerate to …


Quantifying Twentieth Century Glacier Change In The Sierra Nevada, California, Hassan J. Basagic Jan 2008

Quantifying Twentieth Century Glacier Change In The Sierra Nevada, California, Hassan J. Basagic

Dissertations and Theses

Numerous small alpine glaciers occupy the high elevation regions of the central and southern Siena Nevada, California. These glaciers change size in response to variations in climate and are therefore important indicators of climate change. An inventory based on USGS topographic maps (l :24,000) revealed 1719 glaciers and perennial snow and ice features for a total area of 39.l5 ±7.52 km2. The number of 'true' glaciers, versus non-moving ice, is estimated to be 118, covering 15.87 ± 1.69 Km2. All glaciers were located on north to northeast aspects, at elevations >3000 m. Historical photographs, geologic evidence, …


Geochemical Evidence For Airborne Dust Additions To Soils In Channel Islands National Park, California, Daniel R. Muhs, James R. Budahn, Donald L. Johnson, Marith Reheis, Jossh Beann, Gary Skipp, Eric Fischer, Julia A. Jones Jan 2008

Geochemical Evidence For Airborne Dust Additions To Soils In Channel Islands National Park, California, Daniel R. Muhs, James R. Budahn, Donald L. Johnson, Marith Reheis, Jossh Beann, Gary Skipp, Eric Fischer, Julia A. Jones

United States Geological Survey: Staff Publications

There is an increasing awareness that dust plays important roles in climate change, biogeochemical cycles, nutrient supply to ecosystems, and soil formation. In Channel Islands National Park, California, soils are clay-rich Vertisols or Alfi sols and Mollisols with vertic properties. The soils are overlain by silt-rich mantles that contrast sharply with the underlying clay-rich horizons. Silt mantles contain minerals that are rare or absent in the volcanic rocks that dominate these islands. Immobile trace elements (Sc-Th-La and Ta-Nd-Cr) and rare-earth elements show that the basalt and andesite on the islands have a composition intermediate between upper-continental crust and oceanic crust. …


Isotopic Evidence For The Diversity Of Late Quaternary Loess In Nebraska: Glaciogenic And Nonglaciogenic Sources, John N. Aleinikoff, Daniel R. Muhs, E. Arthur Bettis Iii, William C. Johnson, C. Mark Fanning, Rachel Benton Jan 2008

Isotopic Evidence For The Diversity Of Late Quaternary Loess In Nebraska: Glaciogenic And Nonglaciogenic Sources, John N. Aleinikoff, Daniel R. Muhs, E. Arthur Bettis Iii, William C. Johnson, C. Mark Fanning, Rachel Benton

United States Geological Survey: Staff Publications

Pb isotope compositions of detrital K-feldspars and U-Pb ages of detrital zircons are used as indicators for determining the sources of Peoria Loess deposited during the last glacial period (late Wisconsin, ca. 25–14 ka) in Nebraska and western Iowa. Our new data indicate that only loess adjacent to the Platte River has Pb isotopic characteristics suggesting derivation from this river. Most Peoria Loess in central Nebraska (up to 20 m thick) is non-glaciogenic, on the basis of Pb isotope ratios in K-feldspars and the presence of 34-Ma detrital zircons. These isotopic characteristics suggest derivation primarily from the Oligocene White River …


Origin And Paleoclimatic Significance Of Late Quaternary Loess In Nebraska: Evidence From Stratigraphy, Chronology, Sedimentology, And Geochemistry, Daniel R. Muhs, E. Arthur Bettis Iii, John N. Aleinikoff, John P. Mcgeehin, Jossh Beann, Gary Skipp, Brian D. Marshall, Helen M. Roberts, William C. Johnson, Rachel Benton Jan 2008

Origin And Paleoclimatic Significance Of Late Quaternary Loess In Nebraska: Evidence From Stratigraphy, Chronology, Sedimentology, And Geochemistry, Daniel R. Muhs, E. Arthur Bettis Iii, John N. Aleinikoff, John P. Mcgeehin, Jossh Beann, Gary Skipp, Brian D. Marshall, Helen M. Roberts, William C. Johnson, Rachel Benton

United States Geological Survey: Staff Publications

Loess is one of the most extensive surficial geologic deposits in mid-continental North America, particularly in the central Great Plains region of Nebraska. Last-glacial-age loess (Peoria Loess) reaches its greatest known thickness in the world in this area. New stratigraphic, geochronologic, mineralogic, and geochemical data yield information about the age and provenance of Peoria Loess, as well as evaluation of recent climate models.


Holocene Multidecadal- To Millennial-Scale Hydrologic Variability On The South American Altiplano, Erick Ekdahl, Sherilyn C. Fritz, Paul A. Baker, Catherine Rigsby, Kirstin Coley Jan 2008

Holocene Multidecadal- To Millennial-Scale Hydrologic Variability On The South American Altiplano, Erick Ekdahl, Sherilyn C. Fritz, Paul A. Baker, Catherine Rigsby, Kirstin Coley

Department of Earth and Atmospheric Sciences: Faculty Publications

Precipitation on the South American Altiplano varies at a range of temporal scales. A long-term secular increase in moisture availability from the early/mid Holocene to the present, driven by increasing summer insolation resulting from precessional changes in the Earth’s orbit, has been documented in earlier studies. However, higher frequency Holocene variability is not yet understood. Here we present high-resolution diatom assemblage data from two small Altiplano lakes, Lago Lagunillas and Lago Umayo, indicating changes in effective moisture in the southern tropical Andes at decadal, centennial and millennial timescales throughout the mid to late Holocene. A strong millennial-scale component, similar in …


Range-Wide Phylogeographic Analysis Of The Spotted Frog Complex (Rana Luteiventris And Rana Pretiosa) In Northwestern North America, W. Chris Funk, Christopher A. Pearl, Hope M. Draheim, Michael J. Adams, Thomas D. Mullins, Susan M. Haig Jan 2008

Range-Wide Phylogeographic Analysis Of The Spotted Frog Complex (Rana Luteiventris And Rana Pretiosa) In Northwestern North America, W. Chris Funk, Christopher A. Pearl, Hope M. Draheim, Michael J. Adams, Thomas D. Mullins, Susan M. Haig

United States Geological Survey: Staff Publications

The dynamic geological and climatic history of northwestern North America has made it a focal region for phylogeography. We conducted a range-wide phylogeographic analysis of the spotted frog complex (Rana luteiventris and Rana pretiosa) across its range in northwestern North America to understand its evolutionary history and the distribution of clades to inform conservation of R. pretiosa and Great Basin R. luteiventris, candidates for listing under the US Endangered Species Act. Mitochondrial DNA sequence data from a segment of the cytochrome b gene were obtained from 308 R. luteiventris and R. pretiosa from 96 sites. Phylogenetic analysis …


Hydrological Response Patterns And Solute Flux In Canadian Shield Basins: Role Of Different Physical Features And Antecedent Moisture Conditions, Jessica Mueller Jan 2008

Hydrological Response Patterns And Solute Flux In Canadian Shield Basins: Role Of Different Physical Features And Antecedent Moisture Conditions, Jessica Mueller

Theses and Dissertations (Comprehensive)

Patterns of stream flow in relatively undisturbed Canadian Shield basins are closely linked to their physical and vegetative characteristics and meteorological conditions. The physical characteristics include topography, soil-till composition, depth and structure, slope morphology and bedrock geology. Hydrological flowpaths through, and in-situ chemical processes in the soil-till matrix are influenced greatly by the composition of these features and by the antecedent hydrological conditions preceding a given storm or snowmelt event.

A long term data set, collected by the Dorset Environmental Science Centre, is used to examine eight forested basins within the Muskoka-Haliburton region of south-central Ontario. The basins have a …


Dwelling, Walking, Serving: Organic Preservation Along The Camino De Santiago Pilgrimage Landscape, Mercedes Chamberlain Quesada-Embid Jan 2008

Dwelling, Walking, Serving: Organic Preservation Along The Camino De Santiago Pilgrimage Landscape, Mercedes Chamberlain Quesada-Embid

Antioch University Dissertations & Theses

This study is an exploration of the people and the landscape of the well-known Camino de Santiago pilgrimage route. Although there are many routes that make up the entirety of the pilgrimage, this research is specifically focused on the landscape of the Camino Francés, or French Route, in northern Spain. The path has been written about in many ways and for a myriad of reasons since it became affiliated with the Christian tradition in the early ninth century. This research, however, is different. By way of an environmental history and hermeneutic approach, an investigation of the interrelated and overlapping human …


Environmental Monitoring In The Mechara Caves, Southeastern Ethiopia: Implications For Speleothem Palaeoclimate Studies, Asfawossen Asrat, Andy Baker, Melanie J. Leng, John Gunn, Mohammed Umer Jan 2008

Environmental Monitoring In The Mechara Caves, Southeastern Ethiopia: Implications For Speleothem Palaeoclimate Studies, Asfawossen Asrat, Andy Baker, Melanie J. Leng, John Gunn, Mohammed Umer

International Journal of Speleology

The interpretation of palaeoclimate records in speleothems depends on the understanding of the modern climate of the region, the geology, the hydrology above the caves, and the within-cave climate. Monitoring within-cave climate variability, geochemistry of speleothem-forming drip waters, and associated surface and groundwater, provides a modern baseline for interpretation of speleothem palaeohydrological and palaeoclimate records. Here, we present results of such monitoring of the Mechara caves in southeastern Ethiopia, conducted between 2004 and 2007. Results show nearly constant within-cave climate (temperature and humidity) in all caves, which generally reflects the surface climate. Groundwater and surface water geochemistry is similar across …