Physical Sciences and Mathematics Commons^™

Late Quaternary Mega-Lakes Fed By The Northern And Southern River Systems Of Central Australia: Varying Moisture Sources And Increased Continental Aridity, T Cohen, G Nanson, John Jansen, B Jones, Z Jacobs, J Larsen, J.-H May, P Treble, D Price, A Smith

B. G. Jones

Optically stimulated and thermoluminescence ages from relict shorelines, along with accelerator mass spectrometer 14C ages from freshwater molluscs reveal a record of variable moisture sources supplied by northern and southern river systems to Lake Mega-Frome in southern central Australia during the late Quaternary. Additional lacustrine, palynological and terrestrial proxies are used to reconstruct a record that extends back to 105 ka, confirming that Lakes Mega-Frome and Mega-Eyre were joined to create the largest system of palaeolakes on the Australian continent as recently as 50-47 ka. The palaeohydrological record indicates a progressive shift to more arid conditions, with marked drying after …

Proton Induced X-Ray Emission Spectrometry Of Atmospheric Aerosols At Piseco Lake, Adam Margulies

Honors Theses

Chemical studies of lakes and aerosols in the Adirondack region of New York State have found evidence of environmental pollution resulting in acid rain. We obtained air samples for July and September 2012 from Piseco Lake and analyzed particulate depositions with Proton Induced X-ray Emission (PIXE) spectrometry. We detected an array of light elements, including sulfur particulates in the 0.25 - 8 μm range, possibly stemming from coal combustion in the Appalachians and Mid-West of the United States. We also found systematic errors with the accelerator charge integration system due to beam spreading after the beam passes through the target. …

Lake Site Assessments: Us Epa Time-New England Lakes, Sarah J. Nelson, Adam Baumann, Alesha Coffin, Ken Johnson, Catherine Schmitt, Kristin Strock

Forest Resources Faculty Scholarship

TIME (Temporally Integrated Monitoring of Ecosystems) is a statistically selected population of lakes in New Eng- land and the Hudson Valley (31 lakes) and the Adirondacks (43 lakes) that were selected from the original 1991 EMAP-SW (Environmental Monitoring and Assessment Program–Surface Waters) population with acid neutralizing capacity less than 100 meq/L (Young & Stoddard 1996). Samples are taken annually, during a summer base-flow ‘index period’. This sampling strategy is used to reduce hydrologic impact on water chemistry and hence provide an assessment of trends in chemistry with the least number of samples (e.g., Stoddard et al. 2003).

The EMAP program …

Holocene Paleo-Environmental Variability Reconstructed From A Lake Sediment Record From Southeast Greenland, Gregory A. De Wet

Masters Theses 1911 - February 2014

Arctic climate variability over the Holocene has been both extensive and, at times, abrupt. Current understanding of these changes is still quite limited with few high-resolution paleoclimate records available for this period. In order to place observed and predicted 21^st century climate change in perspective, reliable and highly resolved paleo-reconstructions of Arctic climate are essential. Using an 8.5 m sediment core from Nanerersarpik Lake, this project will characterize climate changes during the Holocene, including the deglacial transition, the rapid changes that are known to have occurred around 8,200 years ago, the transition from Holocene thermal maximum (HTM) to the …

Phytoplankton In Virginia Lakes And Reservoirs, Harold G. Marshall

Virginia Journal of Science

This study involves a phytoplankton summer/autumn survey in 46 Virginia lakes and reservoirs during 2010-2012. A total of 307 taxa were identified which included several filamentous and colonial cyanabacteria in bloom concentrations. With the exception of one natural lake, the other sites sampled represent impoundments created decades ago, with the majority presently classified as meso- or eutrophic. Among the cyanobacteria were 6 known toxin producers (Anabaena circinalis, Anabaena spiroides, Aphanizomenon flos-aquae, Cylindrospermopsis raciborskii, Limnothrix redekei, and Microcystis aeruginosa). The study characterizes phytoplankton populations in these aging freshwater habitats taken from a large number …

Phytoplankton In Virginia Lakes And Reservoirs, Harold G. Marshall

Biological Sciences Faculty Publications

This study involves a phytoplankton summer/autumn survey in 46 Virginia lakes and reservoirs during 2010-2012. A total of 307 taxa were identified which included several filamentous and colonial cyanabacteria in bloom concentrations. With the exception of one natural lake, the other sites sampled represent impoundments created decades ago, with the majority presently classified as meso- or eutrophic. Among the cyanobacteria were 6 known toxin producers (Anabaena circinalis, Anabaena spiroides, Aphanizomenon flos-aquae, Cylindrospermopsis raciborskii, Limnothrix redekei, and Microcystis aeruginosa). The study characterizes phytoplankton populations in these aging freshwater habitats taken from a large number …

A Preliminary Examination Of An In Situ Dual Dye Approach To Measuring Light Fluxes In Lotic Systems, Elizabeth C. Minor, Elizabeth James, Jay A. Austin, Veronica Nelson, Ryan Lusk, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

Light is a critical parameter in aquatic ecosystems, affecting primary production and in situ photochemistry. However, measuring light exposure for suspended particles or dissolved components in a dynamic water column can be challenging with existing Eulerian approaches. Here, we assess the simultaneous deployment of two dyes differing in photolability (rhodamine WT and fluorescein) as a Lagrangian measure of sunlight exposure in a lotic system. Fluorescein is sensitive to light exposure; rhodamine WT is relatively photostable. We examined dye fluorescence at various pH, salinity, and temperature conditions. We also tested dye photolability as a function of pH and wavelength range. In …