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Earth Sciences

2007

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Articles 631 - 643 of 643

Full-Text Articles in Physical Sciences and Mathematics

Resolving Terrain Effects In Borehole Temperature Profiles, Shannon M. Heinle Jan 2007

Resolving Terrain Effects In Borehole Temperature Profiles, Shannon M. Heinle

Theses and Dissertations

The study of borehole paleoclimatology aids scientists in determining past climate changes and in understanding current climate trends. Accurate borehole temperature logs are necessary to obtain a useful temperature profile. However, as many climate workers have discovered, borehole temperature profiles can have many causes of inaccuracy. Uncertainties associated with borehole data include errors stemming from temperature measurement, depth measurement, thermophysical property measurements, and terrain effects. Terrain effects include topography, changes in land cover over time, direct and diffused sun radiation, and groundwater flow.

This study focused on specific terrain effects influencing borehole temperature profiles in the United States borehole dataset …


Investigation Of A Possible Lead-Lag Relationship Between The Innuitian And Laurentide Ice Sheets, Arctic Canada, Paula Zimmerman Jan 2007

Investigation Of A Possible Lead-Lag Relationship Between The Innuitian And Laurentide Ice Sheets, Arctic Canada, Paula Zimmerman

OES Theses and Dissertations

Peaks of iron-rich grains in Arctic Ocean sediment cores matched to the Laurentide and Innuitian Ice Sheets appear to show a lead-lag relationship during the Late Pleistocene when grain abundances are plotted against time and depth below sea floor. Cores from across the Arctic have been analyzed to determine if this is the case. Of the six IRD events identified, the Innuitian leads 68% of the time with 26% of events in all cores occurring simultaneously. The Innuitian seems to lead 33.3% of the time when peaks from the Innuitian and Laurentide occur within close proximity (less than 1 cm), …


Plant Assemblage Structure On Barrier Island ‘Pimple’ Dunes At The Virginia Coast Reserve Long-Term Ecological Research Site, Brett A. Mcmillan Jan 2007

Plant Assemblage Structure On Barrier Island ‘Pimple’ Dunes At The Virginia Coast Reserve Long-Term Ecological Research Site, Brett A. Mcmillan

Biological Sciences Theses & Dissertations

The habitats at the VCR LTER that were the focus of the current study are the Hog Island and Parramore Island 'pimples', small, rounded dunes forming along main dune ridges of the barrier islands. There are distinct plant assemblage zones found on pimples, although most of these dunes are 10–20 m in diameter. Hypotheses of the study were that fresh water availability was a main determinant of differences between assemblages and that pimple size and location would influence diversity and assemblage structure. Research goals were (1) to describe the plant assemblages on pimples, (2) to relate edaphic and geomorphological factors …


Bonebeds: Genesis, Analysis, And Paleobiological Significance, Raymond Rogers, Daivd Eberth, Anthony Fiorillo Dec 2006

Bonebeds: Genesis, Analysis, And Paleobiological Significance, Raymond Rogers, Daivd Eberth, Anthony Fiorillo

Raymond Rogers

No abstract provided.


The Diachroneity Of Alluvial-Fan Lithostratigraphy?: A Test Case From Southeastern Ebro Basin Magnetostratigraphy, Nicholas Swanson-Hysell, David Barbeau Dec 2006

The Diachroneity Of Alluvial-Fan Lithostratigraphy?: A Test Case From Southeastern Ebro Basin Magnetostratigraphy, Nicholas Swanson-Hysell, David Barbeau

David L Barbeau Jr

Alluvial-fan strata contain valuable proxy data for kinematic, climatic and sediment-flux phenomena associated with high-relief source regions. Proper application of this data is dependent upon acquisition of accurate high-resolution chronostratigraphic data, best achieved through magnetostratigraphy. Collection of magnetostratigraphic and other proxy data from composite alluvial-fan sections assumes the chronostratigraphic significance of lithostratigraphy. We present the first test of this assumption with new magnetostratigraphy collected from Paleogene rocks of the southeastern Ebro basin. We report five new magnetostratigraphic sections that collectively sample 850 m of alluvial-fan and associated fluvial strata. One-hundred meters of lithostratigraphic overlap between these sections reveals equivalent magnetic …


Evidence Of Four Generations Of Monazite Growth In Proterozoic Migmatites Of The Santa Fe Range, North-Central New Mexico, Dan Heuer Dec 2006

Evidence Of Four Generations Of Monazite Growth In Proterozoic Migmatites Of The Santa Fe Range, North-Central New Mexico, Dan Heuer

Dan Heuer

No abstract provided.


U.S. Policy, John Dernbach Dec 2006

U.S. Policy, John Dernbach

John C. Dernbach

No abstract provided.


Stabilizing And Then Reducing U.S. Energy Consumption: Legal And Policy Tools For Efficiency And Conservation, John Dernbach Dec 2006

Stabilizing And Then Reducing U.S. Energy Consumption: Legal And Policy Tools For Efficiency And Conservation, John Dernbach

John C. Dernbach

Rising global demand for energy, high energy prices, climate change, and the threat of terrorism all point to the need for greater energy efficiency and conservation in the United States. While technological innovation is plainly needed, our laws and institutional arrangements must also play an important role. The United States has scores of legal and policy tools from which to choose to improve energy efficiency and curb energy consumption. This article evaluates a handful of these tools: transit-oriented development; fuel taxation; real-time pricing for electricity use; public benefit funds; improved efficiency in existing residential and commercial buildings; and expanded use …


Trace Element Chemistry Of Zircons From Oceanic Crust: A Method For Distinguishing Detrital Zircon Provenance, C B. Grimes, B E. John, P B. Kelemen, F K. Mazdab, J L. Wooden, M J. Cheadle, K Hanghoj, J J. Schwartz Dec 2006

Trace Element Chemistry Of Zircons From Oceanic Crust: A Method For Distinguishing Detrital Zircon Provenance, C B. Grimes, B E. John, P B. Kelemen, F K. Mazdab, J L. Wooden, M J. Cheadle, K Hanghoj, J J. Schwartz

Barbara John

We present newly acquired trace element compositions for more than 300 zircon grains in 36 gabbros formed at the slow-spreading Mid-Atlantic and Southwest Indian Ridges. Rare earth element patterns for zircon from modern oceanic crust completely overlap with those for zircon crystallized in continental granitoids. However, plots of U versus Yb and U/Yb versus Hf or Y discriminate zircons crystallized in oceanic crust from continental zircon, and provide a relatively robust method for distinguishing zircons from these environments. Approximately 80% of the modern ocean crust zircons are distinct from the fi eld defi ned by more than 1700 continental zircons …


Woodville Ice Cave (Hants County, Nova Scotia) And Notes On The “Ice Caves” Of The Canadian Maritimes, Max Moseley Dec 2006

Woodville Ice Cave (Hants County, Nova Scotia) And Notes On The “Ice Caves” Of The Canadian Maritimes, Max Moseley

Max Moseley

Several caves and sinkholes where snow and ice persist well into t he summer exist in Nova Scotia and New Brunswick. In the past they were sometimes used as a source of ice or for cold storage, and are known locally as 'ice caves' or 'ice holes'. Although they are not true ice caves i n the speleological sense o f the term because t hey do not contain p erenniailc e,t hey are very similar.W oodville l ce Cave in Hants County, Nova Scotia, described h ere,i s a particularly g ood e xample. Invertebrates and bats recorded from …


Overcoming The Behavioral Impetus For Greater U.S. Energy Consumption, John C. Dernbach Dec 2006

Overcoming The Behavioral Impetus For Greater U.S. Energy Consumption, John C. Dernbach

John C. Dernbach

No abstract provided.


In The Heat Of The Law, It's Not Just Steam: Geothermal Resources And The Impact On Thermophile Biodiversity, Donald J. Kochan, Tiffany Grant Dec 2006

In The Heat Of The Law, It's Not Just Steam: Geothermal Resources And The Impact On Thermophile Biodiversity, Donald J. Kochan, Tiffany Grant

Donald J. Kochan

Significant research has been conducted into the utilization of geothermal resources as a ‘green’ energy source. However, minimal research has been conducted into geothermal resource utilization and depletion impacts on thermophile biodiversity. Thermophiles are organisms which have adapted over millions of year to extreme temperature and chemical compositions and exist in hot springs and other geothermal resources. Their ability to withstand high temperatures makes them invaluable to scientific and medical research. Current federal and California case law classify geothermal resources as a mineral, not a water resource. Acquisition of rights to develop a geothermal resource owned or reserved by the …


Digital Elevation Accuracy And Grid Cell Size: Effects On Computed Topographic Attributes, Rob H. Erskine, Timothy R. Green Dec 2006

Digital Elevation Accuracy And Grid Cell Size: Effects On Computed Topographic Attributes, Rob H. Erskine, Timothy R. Green

Timothy R. Green

Terrain attributes are commonly used to explain the spatial variability of agronomic, pedologic, and hydrologic variables. The terrain attributes studied here (elevation, slope, aspect, and curvature) are estimated readily from digital elevation models (DEMs), but questions remain about how the accuracy and sample spacing of the elevation data affect the estimated attributes. The main objective of this study was to quantify differences in each terrain attribute due to factors affecting DEM accuracy and grid cell size. Three data sources were compared: (i) real-time kinematic global positioning system (RTKGPS); (ii) satellite-differentially corrected global positioning system (DGPS); and (iii) U.S. Geological Survey …