Dissertations / Theses: 'Lake'

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Schnellmann, Michael P. Schnellmann Michael P. "Late quaternary mass movements in a perialpine lake (Lake Lucerne, Switzerland) /." [S.l.] : [s.n.], 2004. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=15533.

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O'Connor, Jim E. "Hydrology, hydraulics, and sediment transport of pleistocene Lake Bonneville flooding on the Snake River, Idaho." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/191159.

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Approximately 14,500 years ago, Pleistocene Lake Bonneville discharged 4750 km 3 of water over the divide between the closed Bonneville Basin and the watershed of the Snake River. The resulting flood, emanating from the divide at Red Rock Pass, Idaho, followed the present courses of Marsh Creek, the Portneuf River, and the Snake and Columbia Rivers before reaching the Pacific Ocean. For the 1100 kilometers between Red Rock Pass and Lewiston, Idaho, the Bonneville Flood left a spectacular array of flood features that have allowed for geologic reconstruction and quantitative evaluation of many aspects of the flood hydrology, hydraulics, and sediment transport. Geologic evidence of maximum flood stages in conjunction with step-backwater modeling provides for peak discharge estimates and understanding of local hydraulic flow conditions for ten separate reaches along the flood route. Peak discharge was approximately 1.0 million m³•sec⁻¹ at the Lake Bonneville outlet near Red Rock Pass. Downstream, the maximum discharge had attenuated to 0.57-0.62 million m³•sec⁻¹ by arrival at Lewiston. Attenuation was primarily the result of flow storage in the wide alluvial valleys of the western Snake River Plain. The local hydraulic conditions (depth and velocity) of the Bonneville Flood varied significantly within and between the study reaches. The rate of energy expenditure was also highly varied; local calculated stream-power values ranged from less than 10 watts•m² to 100,000 watts•m². Greater than 60% of the total energy loss at peak discharge was expended in a total distance that encompassed less than 10% of the flood route. These spatial variations in local hydraulic conditions were profoundly important in controlling the distribution of flood processes and features. The deposition of tractively-transported cobbles and boulders (measured diameters ranged from less than 10 cm to greater than 10 m) occurred in reaches of decreasing flow energy within quantitatively-definable limits of flow energy. Areas of erosion are more difficult to precisely evaluate; however, they were restricted to reaches of greater stream power. It is likely that cavitation was an important erosional agent in many areas of most intense flow conditions.

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Metcalfe, Elisabet Joan. "Late-glacial through Holocene Stratigraphy and Lake-level Record of Rangely Lake, Western Maine." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/MetcalfeEJ2007.pdf.

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Maki, Angela Pelkie. "Effects of Air Temperature and Lake Ice on Snowfall on the South Shore of Lake Superior." ScholarWorks@UNO, 2009. http://scholarworks.uno.edu/td/941.

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Lake Superior is a forcing factor for local weather systems, causing substantial amounts of lake effect snow in the winter (particularly on the south shore). This study assesses decreasing ice cover of Lake Superior and its effects upon synoptic weather factors. Data were collected from eleven National Weather Service (NWS) stations located on the south shore of the lake. Rainfall and snowfall amounts from December to May were regressed on percent ice coverage and average monthly temperatures from 1972-2002. Ice coverage and average monthly temperature had a negative relationship with snowfall and rainfall.

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Sapota, Tomasz. "Late Cenozoic Geoarchives from Lake Baikal, Siberia." Doctoral thesis, Uppsala University, Department of Earth Sciences, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4552.

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Three long sediment cores (BDP-98 – 600 m, BDP-96 – 200 m and BDP-93 – 100 m) drilled in Lake Baikal (Siberia) have been studied with the aims of establishing an absolute chronology and reconstructing paleoclimatic and paleoenvironmental changes in the region. The location of the lake at relatively high latitude and continental interior and a thick continuous sedimentary archive that developed in a rift system tectonic setting provide unique material for this investigation. The cosmogenic isotope ¹⁰Be was used for dating and the results indicate time spans of 8 (+0.8\-0.6) Myr for BDP-98, 5.5 (±0.13) Myr for BDP-96 and >0.7 Myr for BDP-93. Two major sedimentary facies (deltaic and hemipelagic) are distinguished by textural geochemical and mineralogical data. Detrital mineral composition suggests negligible change in provenance during the period studied. Formation of authigenic minerals, such as framboidal pyrite, vivianite and siderite, reflects variable environmental conditions in the lake and climate change in the region. Biogenic silica content shows climatic influence, which is modified by the supply of detrital material and postdepositional alterations. ¹⁰Be dating, combined with lithological analysis of the sediments, makes it possible to place temporal constrains on climate cooling at the Miocene/Pliocene boundary (5 Myr ago) and at the Early/Late Pliocene boundary (3.6 Myr ago) as well as the beginning of the northern hemisphere glaciation at about 2.5–2.6 Myr ago. The regional east-west tectonic extension of south-east Asia, related to Tibetan Plateau uplift, was confined in the Baikal area to between about 7 and 5 Myr ago, with a rifting rate calculated at 7 mm year^-1. Furthermore, the ¹⁰Be data suggest that geomagnetic field intensity strengthened around the Miocene/Pliocene boundary.

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Lacey, Jack H. "Late Quaternary palaeoenvironmental reconstruction from Lake Ohrid." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/31993/.

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Lake Ohrid is a large, deep, ancient lake located on the Balkan Peninsula and has an extraordinary degree of endemic biodiversity. A deep drilling campaign was carried out in 2013 as part of the Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO) project to better understand the influence of climate and environmental change on evolutionary patterns and endemism. Initial results from a 569 m sediment succession drilled in the centre of the basin indicate continuous lacustrine conditions over the past ca. 1.2 Ma. This thesis presents new stable isotope data from carbonate within the upper 248 m of the composite profile, covering the last ca. 640 ka at a millennial-scale resolution (≈ 0.5 ka). Isotope data are used to provide a long-term palaeoenvironmental reconstruction, which is supported by a quantitative model of modern lake water isotope composition and a detailed multi-proxy investigation of climate evolution since the last glacial period. Water balance calculations confirm Ohrid to be an evaporative system with a complex hydrology. Variations in the isotope composition of modern lake water are suggested to represent long-term fluctuations in water balance. A trend from wetter to drier conditions through the Holocene is consistent with regional and hemispheric processes related to changes in insolation. Over the last ca. 640 ka, endogenic calcite is precipitated in abundance during warm stages, however carbonate is negligible during glacial periods with the exception of discrete horizons comprising early diagenetic authigenic siderite. The oxygen isotope composition of lake water, calculated using calcite and siderite, indicates more evaporated conditions during warm stages and fresher lake water in glacial phases. Low frequency variability shown by calcite isotope data suggests relatively stable conditions before ca. 450 ka, a transition to a wetter climate between ca. 400-250 ka, and a trend to drier climate conditions after ca. 250 ka. Higher frequency millennial-scale oscillations and abrupt climate events observed during warm stages are likely associated with regional climate change as a function of orbital forcing. This study emphasises the potential of Lake Ohrid as a valuable archive of climate change in the central Mediterranean region and demonstrates the efficacy of isotope data for palaeoenvironmental reconstruction at Lake Ohrid.

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Lally, Corinne M. "Late Pleistocene to Holocene climate variability recorded in lake sediment of Silver Lake, Summit County, Ohio." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1479127321585964.

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Olago, Daniel Ochieng. "Late Quaternary lake sediments of Mount Kenya, Kenya." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296036.

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Griffiths, S. J. "Late Quaternary palaeoclimatology of Lake Kopais, central Greece." Thesis, Swansea University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.507951.

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Ferian, Michael R. "The Effect of Global Temperature Increase on Lake-Effect Snowfall Downwind of Lake Erie." Ohio University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1229968622.

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Panizzo, V. N. "Late Holocene environmental change : evidence from Lake Xiaolongwan, north east China and Lake Arachlei, south eastern Siberia." Thesis, University College London (University of London), 2010. http://discovery.ucl.ac.uk/516143/.

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This project addresses the increasing need for high-resolution proxy studies of environmental change over the late Holocene from regions in northern Eurasia. The late Holocene has been identified as a key timeframe for investigating environmental change (e.g. PAGES Focus 2) due to the relatively small changes in boundary conditions. In particular, this project focuses on two sites; Lake Xiaolongwan, north east China, sensitive to changes in summer (EASM) and winter (EAWM) monsoonal intensity and Lake Arachlei, south east Siberia, sensitive to changes in Westerly transport and Siberian High intensity. This project provides a detailed high-resolution reconstruction of diatoms and bulk organic isotopes from cores collected at each of these sites. The c. 2000 year record from Lake Xiaolongwan, has an age model derived from varve counting, 210Pb and SCPs. Ecological interpretations of diatom changes suggests a long term trend towards decreased lake water level and increased lake productivity (after c. 1650 years BP). Superimposed upon the trend are significant periods of assemblage changes thought to represent intensified EAWM intensity, occuring between c. 1450-1350 and 600-400 years BP, which are coincident with evidence of north Atlantic ice raft debris (IRD) events. At Lake Arachlei, a similar trend of decreasing lake levels is also identified over the c. 3000 year record (based on a 14C and 210Pb age model). Significant assemblage changes are demonstrated between c. 3000-2800, 1450-1350 and 500-400 years BP, thought to indicate reduced Westerly transport to the region. These periods are coincident with Bond events 2, 1 and 0. This project demonstrates the role of teleconnections in the late Holocene, which may be responsible for environmental change. Nevertheless, the dramatic change identified in the Lake Xiaolongwan record after c. 1950 cannot be attributed to evidence of global warming in the region due to the demonstrated evidence of anthropogenic impacts (XRF and SCPs) in this otherwise perceived pristine region.

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Woodbridge, Jessie. "Late-Holocene lake diatom-inferred palaeoclimate from central Tturkey." Thesis, University of Plymouth, 2009. http://hdl.handle.net/10026.1/1308.

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In the semi-arid environment of the Eastern Mediterranean, water can be a limiting resource and its availability is influenced by different climate factors. Knowledge of late Holocene water balance is limited for this region. Lake systems and organisms respond to environmental variability and can be used as a proxy for palaeoclimate. The aims of this research project were to reconstruct late Holocene palaeoclimate using diatom frustules preserved within crater lake sediments in central Turkey. Two lakes (Nar Gölü and Kratergöl), located in the same climate region, were selected for this purpose. Modem lake samples and sediment cores collected between 1999-2006 were subsampled at high resolution for diatom analysis, Nar G610 provided an uninterrupted annually-laminated late Holocene sequence covering the last 1720 years. The varied lake sedimentation rate of Kratergöl was evident in sediment core coarse sandy sections and the sequence was thought to represent the mid-late 20`h century. A diatom-salinity transfer function was employed using existing training sets from the European Diatom Database to infer past water balance. The reconstruction was calibrated with instrumental meteorological data. Reconstructed salinity was limited by poor analogue matching between the palaeo-diatom assemblage and the modem training set. This was partly associated with the presence of a previously undescribed diatom genus (newly named Clipeoparvus anatolicus), which was highly abundant in the Nar modern environment and sediment record. Additional methods to extract palaeoenvironmental information from the diatom record were explored. This included calibrating diatom DCA axes with instrumental temperature in order to reconstruct palaeo-temperature, identifying mono-specific diatom bloom events in situ on core thin section slides, calculating diatom biovolume, concentration, diversity and grouping species according to their habitat preferences. Comparison of the Nar and Kratergöl records highlighted the advantages of annually laminated lake sediments for palaeoenvironmental research and the limitations of sediment sequences from lakes with a varied sedimentation rate and poor chronological control. The primary meteorological control on the Nar diatom population was identified as summer temperature, via the link with lake water salinity. The Nar diatom sequence was compared with an oxygen isotope (palaeo-evaporation) and pollen record (human land use) from the same sediment cores and palaeoclimate reconstructions from other sites and regions. Nar diatoms and oxygen isotopes revealed that Cappadocia experienced high aridity prior to AD 540 and mono-specific diatom bloom events have become increasingly common during the most recent -400 years. A diatom assemblage shift at AD 2001 also indicated a recent change in the system. Human land use evident in the pollen sequence may have influenced the diatom relationship with climatic variability in the later part of the record. The Kratergöl diatom record indicated environmental variability throughout the mid-late 20`h century; however, interpretations were limited due to chronological discrepancies. The annually laminated Nar diatom record has provided a detailed account of palaeoenvironmental variability in central Anatolia throughout the late Holocene and contributes towards our understanding of Eastern Mediterranean palaeoclimate.

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Sadurski, Stephen Edward. "The Biogeochemistry of Carbon Isotopes in Local Lakes." Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1357745315.

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14

Balangoda, Anusha. "Impact of Artificial Aeration on Nutrients in Small Eutrophic Lakes." Diss., North Dakota State University, 2014. http://hdl.handle.net/10365/24669.

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15

YAN, Dada [Verfasser]. "Interplay between Lake and Catchment Processes in Kuhai Lake Basin, NE Tibetan Plateau, China, during Late Holocene / Dada YAN." Berlin : Freie Universität Berlin, 2017. http://d-nb.info/1131629353/34.

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Yan, Dada [Verfasser]. "Interplay between Lake and Catchment Processes in Kuhai Lake Basin, NE Tibetan Plateau, China, during Late Holocene / Dada YAN." Berlin : Freie Universität Berlin, 2017. http://d-nb.info/1131629353/34.

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17

Taylor, Julie Ellen. "Lake Unloosed." The University of Montana, 2009. http://etd.lib.umt.edu/theses/available/etd-06012009-102336/.

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Cragwall, Jasper Albert. "Lake Methodism." 24-page ProQuest preview, 2007. http://proquest.umi.com/pqdweb?index=0&did=1335357971&SrchMode=1&sid=5&Fmt=14&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1220030683&clientId=10355.

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Misiti, Patrick J. "The lake." Laramie, Wyo. : University of Wyoming, 2009. http://proquest.umi.com/pqdweb?did=1939245941&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.

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20

Blauvelt, Ryan. "Lake Pleasant." Digital Commons @ Butler University, 2018. https://digitalcommons.butler.edu/grtheses/505.

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Lake Pleasant, a work for wind ensemble, receives its title from the composer’s memories of visiting a cottage on a small lake that straddles the border of Indiana and Michigan. The primary influence of the piece derives from the howling sound produced by the echoes of traffic noise one hears while standing on the opposite side of the lake in the quiet of night. The recollection of this soundscape takes the musical form of nine clarinets spread throughout the audience accompanied by pairs of flutes, oboes, saxophones, trumpets, and a single piccolo. While the placement of performers in the audience allows for the music to emulate the atmosphere evoked by the work’s influence through the use of physical space and timbral similarities, the spacial relationships explored through the music also serve as primary structural elements.

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21

Majmudar, R. N. "Lake pigments." Thesis(Ph.D.), University of Bombay, 2018. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3679.

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22

Snell, Margaret Anderson. "Employing Institutional Economics to Explain the Distribution and Success of Maine Lake Associations." Fogler Library, University of Maine, 2009. http://www.library.umaine.edu/theses/pdf/SnellMA2009.pdf.

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VanDeHey, Justin A. "Genetic structure among Lake Michigan's lake whitefish spawning aggregates /." Link to full text, 2007. http://epapers.uwsp.edu/thesis/2007/vandehey.pdf.

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24

Roningen, Jeanne Marie. "Hydrogeologic Controls on Lake Level at Mountain Lake, Virginia." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/31950.

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Mountain Lake in Giles County, Virginia, has a documented history of severe natural lake-level changes involving groundwater seepage [Jansons, 2004] that extend over the past 4200 years [Cawley, 1999], and as of December 2010 the lake was about 2% full by volume. Situated in the Valley and Ridge physiographic province on the axis of a plunging anticline and straddling contacts between three upper Ordovician and lower Silurian formations, the lake is one of two natural lakes in Virginia.

A daily water balance, geophysical surveying with dipole-dipole electrical resistivity, and chemical sampling have shed light on the nature of flow to and from the lake, including: 1) the steady nature of net groundwater outflow, 2) the seasonal response to precipitation of a forested first-order drainage system in fractured rock, 3) the influence of a fault not previously discussed in literature regarding the lake, and 4) the possibility of flow pathways through karst features.

Results from a water balance indicate steady lake drainage and significant recharge when vegetation is dormant, particularly during rain-on-snow melt events. The resistivity profiles display a highly heterogeneous subsurface and reveal low-resistivity areas that suggest flow pathways to and from the lake. Well logs, satellite images, and outcrop observations appear to confirm the presence of a fault to the east of the lake. Chemical evidence suggests that karst features may be present in the upper Reedsville-Trenton formation underlying the lakebed.
Master of Science

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25

Straßer, Michael. "Quantifying Late Quaternary natural hazards in Swiss lakes subaquatic landslides, slope stability assessments, Paleoseismic reconstructions and lake outbursts." Zürich Schweizerische Geotechnische Kommission, 2008. http://e-collection.ethbib.ethz.ch/view/eth:30202?q=strasser.

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26

Bigelow, Patricia E. "Predicting areas of lake trout spawning habitat within Yellowstone Lake, Wyoming." Laramie, Wyo. : University of Wyoming, 2009. http://proquest.umi.com/pqdweb?did=1939365861&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.

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27

Grund, Yuan Xiao. "Long-term Variation of Summer Phytoplankton Communities in an Urban Lake in Relation to Lake Management and Climate Conditions." PDXScholar, 2018. https://pdxscholar.library.pdx.edu/open_access_etds/4728.

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Eutrophication is one of the primary factors causing harmful cyanobacteria blooms in freshwater lakes; climate change such as warmer temperature can potentially further increase both frequency and intensity of blooms. This study investigated the long-term changes in water quality and summer phytoplankton assemblages in Oswego Lake, OR, in relation to lake management practices (e.g., hypolimnetic aeration and alum treatments), as well as climatic and regional meteorological conditions. Both water quality and phytoplankton assemblages were sampled biweekly during summer seasons between 2001 and 2013. The concentrations of total phosphorus (TP), soluble reactive phosphorus (SRP) and total nitrogen (TN) decreased 66%, 93% and 31%, respectively, in response to the hypolimnetic aeration and alum treatments since 2005. The results of summer phytoplankton assemblages showed a 62% reduction of cyanobacteria biovolume and a switch from cyanobacteria dominance (2001-2005) to diatom and chlorophyte dominance (2006-2013). Cluster analysis identified four statistically different groups of summer phytoplankton assemblages (denoted Groups 1-4). Nonmetric multidimensional scaling analysis indicated that the four groups were associated with different water quality conditions. Group 1 occurred prior to hypolimnetic aeration and was primarily comprised of cyanobacteria, associated with water conditions of high nutrients and high primary production. Group 2, dominated by cyanobacteria and chlorophytes, occurred between hypolimnetic aeration and alum surface application. Group 2 was associated with turbid water conditions. Group 3 was dominated by diatoms, occurring after alum surface application. Group 4 included R-strategist phytoplankton that quickly respond to environmental changes, occurring in the years following alum injection, drawdown and inflow alum treatment. Both Group 3 and 4 were associated with reduced nutrients in the lake. The results demonstrated a strong temporal relationship between the long-term changes in water quality and summer phytoplankton assemblages and the lake management practices. The Pacific Decadal Oscillation (PDO) index, an El-Niño-like pattern of Pacific climate variability, showed a statistically significant correlation with the summer phytoplankton dynamics, while the multivariate ENSO index (MEI) and regional meteorological variables (air temperature, rainfall, wind speed, wind direction and solar radiation) were not significantly related to the changes of phytoplankton communities during the study period. In conclusion, the study results suggest that the lake management practices had strong effects on both production and community compositions of phytoplankton, and suggest the need for a future study on large-scale climate impacts on lake ecosystems and best management practice.

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Leodolter, Johannes. "A Statistical Analysis of the Lake Levels at Lake Neusiedl." Austrian Statistical Society, 2008. http://epub.wu.ac.at/5634/1/296%2D1009%2D1%2DSM.pdf.

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A long record of daily data is used to study the lake levels of Lake Neusiedl, a large steppe lake at the eastern border of Austria. Daily lake level changes are modeled as functions of precipitation, temperature, and wind conditions. The occurrence and the amount of daily precipitation are modeled with logistic regressions and generalized linear models.

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Hosack, Michael A. "Population dynamics of lake whitefish in Lake Pend Oreille, Idaho /." Link to full text, 2007. http://epapers.uwsp.edu/thesis/2007/Hosack.pdf.

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Thesis (M.S.)--University of Wisconsin--Stevens Point, 2007.
Submitted in partial fulfillment of the requirements for the degree Master of Science in Natural Resources (Fisheries), College of Natural Resources. Includes bibliographical references (leaves 156-174).

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Watson, Michelle Marie. "Investigating the relationship between lake morphology and lake trophic state." Thesis, University of Ulster, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.529552.

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Kelley, John Gormley Walsh. "One-way coupled atmospheric-lake model forecasts for Lake Erie /." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487867541733975.

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McGuire, Kevin Michael. "Comparative Sedimentology of Lake Bonneville and the Great Salt Lake." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/4022.

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Ooids of Great Salt Lake, Utah (GSL) have been studied periodically by geologists since the 1960's. These studies have documented the locations of ooid deposits, bulk composition, mineralogy, and internal structural variations of GSL ooids. Ooids have also been identified in sediment cores from lakes predating the Great Salt Lake, but similar descriptions have not been made for these ooids. Samples of ooids from cores in Pilot Valley, UT/NV and Knolls, UT have been obtained, along with samples from the Great Salt Lake at Bridger Bay and Rozel Point. The cortical fabrics and crystal morphologies of these ooids were studied in thin section and under scanning electron microscopy. Examples of cortex morphologies previously documented in GSL ooids were observed, to some degree, in ooids from Pilot Valley and Knolls. Knolls ooids had unique cortical layers that were resistive to acid and appeared to be dominantly comprised of clays. Bulk dissolution ages were obtained for ooids from each location. Ooids form both Pilot Valley and Knolls had average ages that pre-date Lake Bonneville, whereas GSL ooids from Bridger Bay had an average age of roughly 3,500 years before present (yr BP) and Rozel Point ooids had an average age of 500 yr BP. Along with a bulk age, ooids from Bridger Bay at the Great Salt Lake were subjected to serial dissolutions during which a split of gas was taken from each stage and an age was obtained. Ages spanned 7,000 years with the final dissolution stage delivering an average age of 9,000 yr BP. Based on this data it is likely that GSL ooids at Bridger Bay have been forming since the cessation of Lake Bonneville and that many of the nuclei in Bridger Bay ooids are remnant peloids from the Gilbert level of Lake Bonneville.

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Bartruff, Anthony Lynn. "A Characterization of Lake Abert Tufa Mounds Lake Abert, Oregon." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/1061.

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A series of tufa mounds is found within the northern basin of Lake Abert, located within southeastern Oregon. The mounds have been divided into 3 main groups and 1 sub-group (A1, A2, B, and C) based upon spatial and textural considerations. Mound groups appear at two different elevations: the 1310 meter elevation (Groups A2, B, and C), and the 1318 meter elevation (Group A1). Published carbon age dating of the Lake Abert 1325 meter strandline and the 1310 meter strandline indicates that the mounds were formed during the Late Pleistocene/Early Holocene. Facies analysis and mineralogical analysis of the mounds indicates that the mounds were primarily formed subaqueously during a lake regression, supporting oxygen isotope data from previous researchers. Magnetometer data within Groups A1 and A2 suggests that the mounds are associated with a series of magnetic lows which are oriented in joint sets (NW-SE, and N-S) which match the orientation of faulting within the region. While there appears to be another early mound building episode, no direct evidence confirms this.

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McMahon, W. Arthur. "Lake education project: An environmental program for Lake Elsinore students." CSUSB ScholarWorks, 1994. https://scholarworks.lib.csusb.edu/etd-project/952.

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35

Hopkins, Aareka. "The potential for Charophyte re-establishment in large, shallow, eutrophic lakes with special reference to Lake Waikare, New Zealand." The University of Waikato, 2006. http://hdl.handle.net/10289/2419.

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Lake Waikare is a large, shallow eutrophic lake devoid of submerged macrophytes. I investigated potential methods for re-establishing submerged macrophytes in the lake. Specifically, I subjected charophyte (Chara corallina) plantlets to two treatments of exposure in the lake (in areas exposed and sheltered from wind) to test for survival and growth under these conditions, and inside and outside fish exclosures to test for growth and survival in the presence of fish. While plantlets grew outside the exclosures in winter, their accumulated biomass over 21 days was less than protected plantlets. In winter, the accumulated biomass was lower outside than inside exclosures (by ~40%) at the sheltered site and was lower outside than inside exclosures (by 43%) at the exposed site. Overall, growth rates in winter were higher at the sheltered site (compared to the exposed site) by ~7%. In summer, charophyte accumulated biomass inside the exclosures increased by 85%, while at the sheltered site accumulated biomass increased by 58%. Outside the exclosures in summer the plantlets were completely removed at both sites. Overall, growth rates where higher at the exposed site than the sheltered site by 31%. Fish were responsible for the partial removal of plantlets in winter and total removal of plantlets in summer, and therefore affect the survival and growth of charophytes in Lake Waikare. The embayment at the sheltered site provides the best location in winter for re-establishment of charophytes from oospores because better growth rates were obtained there, and its sheltered location provides protection from severe wave action found at the exposed site. Oospores did not germinate after being submersed in the lake for 90 days due to heavy sedimentation. To induce an improvement in the present light climate, Alum was tested to determine its effectiveness and longevity for settling lake sediments to allow charophytes to establish and grow. Examining the settling rates of Lake Waikare sediments and water treated with Alum over a range of suspended sediment concentrations and time intervals, sediments settled faster with Alum than without for at least 15 days (at 200 g l^1 suspended sediment concentration) and it remained active to 60 days but at reduced effectiveness. At the other concentrations tested (100 g l^1 and 300 g l^1 suspended sediment concentration), Alum responses were insignificant. An improved light climate achieved by fish removal or Alum treatment will likely not be sufficient to permit the re-establishment of submerged macrophytes due to the turbid, algal-dominated state of the lake. The present nutrient and sediment levels, wave climate and fish influence must be mitigated so charophyte plantlets can be established.

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Zastepa, Arthur. "Fate and Persistence of Microcystin Congeners in Lakes and Lake Sediments." Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/30453.

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Cyanobacterial blooms and their toxins are a major water quality and potential health risk around the world. This thesis developed an analytical method for microcystin congeners in sediments in order to examine their fate in lakes and establish the history of toxin-producing cyanobacteria in relation to environmental change using lake sediments. A novel method for both intra- and extracellular microcystins in lake sediments was developed, consisting of accelerated solvent extraction, hydrophilic-lipophilic balance solid phase extraction and multiple reaction monitoring-based HPLC-MS/MS quantitation. The method achieved comparable recoveries of intra- and extracellular cyanotoxins based on nine microcystins and nodularin (marine analogue). The analytical method was validated using surficial and deeper sediments from seven lakes of diverse geography and trophic state. To study the fate of microcystins, a multi-year, whole lake study of Microcystis blooms was conducted to obtain both in situ and in vitro half-life estimates of microcystin-LA (MC-LA), an understudied, but increasingly reported microcystin. MC-LA appeared to undergo slower rates of decomposition and persist longer than the more frequently studied MC-LR. Experimentally, high light intensity increased in vitro decomposition of dissolved MC-LA while high temperature enhanced decomposition in the particulate phase. Sediment deposition measurements and estimates of sediment-pore water distribution coefficients, sediment accumulation rates, and diffusive fluxes indicated that microcystin congeners differ in their fate. Notably, MC-LA preferentially distributed into pore water and remobilized (by diffusion) from sediments and into overlying water while MC-RR adsorbed more strongly to sediment particles. Finally, the sediment record of an eutrophic lake of major recreational importance was examined to identify possible drivers of toxigenic cyanobacteria and determine if the perceived increase in toxigenic cyanobacteria could be corroborated. Microcystins were detected to the bottom of the core (early 1800s), indicating that toxigenic cyanobacteria were present prior to the first permanent settlements. Microcystins were significantly correlated with changes in diatom-inferred nutrients (DI-TP and DI-TKN) within the sediment core as well as with specific algal pigments. Sediment microcystins in the upper layers also significantly correlated with a 20-year monitoring record for water column microcystins suggesting that sediment microcystins can be used as a proxy for past surface water conditions.

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37

Lacourse, Terri. "Late Quaternary vegetation history of Sulphur Lake, southwest Yukon Territory, Canada." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0005/MQ36711.pdf.

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Weller, Samantha Joanne. "The Lake Theatre." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/53947.

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At the beginnings of this thesis, the importance was solely focused on the design of an independent multipurpose theater and the transitions between the public area and backstage. As the year and project progressed, it changed to become a realization and study of architectural experiences within a space. After choosing a site within the Snoqualmie National Forest in Seattle overlooking Lake Serene, decisions were made to design a theater that would not hinder the natural landscape but immerse the audience in it. Years of backpacking, camping, and hiking, I have personal experiences and memories of walking through the shafts of light shining through the canopies of the trees or feeling the dampness that sticks to clothes as you roam through the fog rolling off the mountains. The orientation and exterior choices were made as to not take away from an audience member's experience of the natural surroundings of the area. Blending the building within the mountain hides it from view as to not over take the landscape behind it, the bridge connects the two mountains to each other and the building itself creates an axis towards the lake. The movement through the lobby was designed as a natural progression towards the view as a canopy of timber surrounds the audience, mimicking the trees outside. How we perceive architecture is how we experience it. Creating a space that would not only flow with its natural environment but also have movement inside to assist each individual, whether it is a visitor, stagehand, technician, or performer was my end goal. Focusing my efforts on the visitor, I was able to learn the importance of moments and the simplicity of details. Taking ultimately what Juahani Pallasmaa is quoted saying that "the architectural experience calls for the senses of balance, movement, orientation, continuity, time, self, and existence."
Master of Architecture

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39

Adiyanti, Sri. "A method to estimate chlorophyll-a concentration in the surface layer of a stratified lake from surface layer temperature time series, meteorogical fluxes, a knowledgeof blue-to-red peak absorption ratio and dissolved organic matter concentration /." Connect to this title, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0071.

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40

Bergstedt, Roger Allen. "Seasonal bathythermal habitat use by lake trout and lake whitefish in Lake Huron as measured with implanted archival tags." Diss., Connect to online resource - MSU authorized users, 2008.

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41

Wood, Hannah. "The benthic ecology and food web dynamics of Te Waihora (Lake Ellesmere)." Thesis, University of Canterbury. School of Biological Sciences, 2008. http://hdl.handle.net/10092/2274.

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Coastal and shallow lakes are often subjected to eutrophication due to nutrients from catchment farming activities. Lake Ellesmere (Te Waihora) is a hyper-eutrophic lake which has gained recent attention because of concerns over its ecological health and fishery status. This study investigated the benthic ecology of the lake by extensive spatial and temporal sampling. Eight littoral sites were sampled on a single occasion, and 20 benthic sites were sampled once per season for one year. Water chemistry conditions, substrate and invertebrate communities varied significantly around the lake. Salinity, pH, DO and seston were primarily affected by freshwater inputs from inflow streams and salt water intrusion due to the lake opening to the sea. On these occasions, salinity reached 32 ‰ at the lake outlet. The lake invertebrate community was depauperate, comprising of only two species of invertebrate predators restricted to the littoral zone and eight benthic invertebrate taxa, dominated by oligochaetes, amphipods and chironomids. Benthic invertebrate abundances also reflect the dominant local substrate, where oligochaetes and chironomids preferred areas of silt substrate, whereas Potamopyrgus preferred harder substrate. Stable isotope and gut analysis determined that the primary food sources within the lake were phytoplankton and algae. Macrophytes provided a minimal contribution to the food web, possibly relating to the change in status from a clear water, macrophyte dominated lake to a turbid, phytoplankton dominated condition since the Wahine Storm in 1968. Isotope analysis also showed that the lake food web was markedly different in its carbon values from food webs of its inflow streams and nearby marine source. However the lake food web did show a marine-derived carbon signature. A mesocosm experiment testing the effect of common lentic predators on the abundance of the lake chironomid Chironomus zealandicus, showed that if invertebrate predators were present in the lake they could markedly reduce the abundance of the pest prey species. This study highlights that the frequent re-suspension of bottom sediments, lake level fluctuation resulting in wetting and drying of littoral zones, and the management of the lake opening to the sea all have an effect on the benthic ecology of Te Waihora.

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42

Cox, Benjamin Samuel. "Assessment of an invasive lake trout population in Swan Lake, Montana." Thesis, Montana State University, 2010. http://etd.lib.montana.edu/etd/2010/cox/CoxB0810.pdf.

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The recent invasion of lake trout into the Swan River drainage in Northwest Montana threatens one of the last remaining recreational bull trout fisheries in the USA. An inter-agency group is implementing an experimental lake trout suppression program on Swan Lake. The objectives of this study were to establish a baseline data set on the lake trout population in Swan Lake concurrently with the experimental removal effort, simulate alternative management scenarios using matrix models and identify spawning locations of lake trout to target adult fish and embryos. A commercial gill-net sampling effort provided data to estimate abundance, size structure, age structure, growth, condition, maturity, fecundity, and mortality of lake trout in Swan Lake. Lake trout in Swan Lake grew rapidly, attained large sizes, and were in high condition. The size and age structure of lake trout sampled was skewed towards juvenile lake trout, indicating the population was growing rapidly. Matrix-model simulations also indicated the lake trout population would continue to grow with no suppression efforts, but suppression efforts could reduce the population growth rate. Population growth was particularly sensitive to changes in age-0 survival in population models. Elasticity analysis of matrix simulations indicated survival from birth to sexual maturity, followed by survival of adult fish contributed most to population growth. Lake trout spawning locations were identified using ultrasonic telemetry, short-set gill nets, and in-situ egg nets. Spawning locations identified with acoustic telemetry were confirmed by capturing gravid lake trout in gill nets and lake trout eggs in the substrate. These results suggest that the inter-agency group should focus removal efforts on sub-adult and adult lake trout at if extirpation of the population is the goal. Given the uncertainty in the vital rates and the potential bias in exploitation rates used to model suppression scenarios, annual suppression efforts should be increased from the 2008 level to ensure a decline in the lake trout population.

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McKinnon-Newton, Laurie. "Ecology of plankton in a terminal lake Walker Lake, Nevada, USA /." abstract and full text PDF (free order & download UNR users only), 2007. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1446303.

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44

Marsham, John. "Lake temperatures : thermal remote sensing and assimilation into a lake model." Thesis, University of Edinburgh, 2003. http://hdl.handle.net/1842/12576.

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Nielsen, Shauna. "Sediment Dynamics of a Shallow Hypereutrophic lake: Lake Jesup, Florida, USA." FIU Digital Commons, 2011. http://digitalcommons.fiu.edu/etd/511.

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Improved knowledge of sediment dynamics within a lake system is important for understanding lake water quality. This research was focused on an assessment of the vertical sediment flux in Lake Jesup, a shallow (1.3 m average depth) hypereutrophic lake of central Florida. Sediment dynamics were assessed at varying time scales (daily to weekly) to understand the transport of sediments from external forces; wind, waves, precipitation and/or runoff. Four stations were selected within the lake on the basis of water depth and the thicknesses of unconsolidated (floc) and consolidated sediments. At each of these stations, a 10:1 (length to diameter) high aspect ratio trap (STHA) was deployed to collect particulate matter for a one to two week period. The water and sediment samples were collected and analyzed for total carbon (TC), total phosphorus (TP) and total nitrogen (TN). Mass accumulation rates (MAR) collected by the traps varied from 77 to 418 g m-2 d-1 over seven deployments. TN, TP and TC sediment concentrations collected by the traps were consistently higher than the sediments collected by coring the lake bottom and is most likely associated with water column biomass. A yearly nutrient budget was determined from August 2009 to August 2010 with flux calculated as 2,033,882 mt yr-1.

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46

Herbst, Seth. "Status of Lake Whitefish (Coregonus Clupeaformis) in Lake Champlain, 2006-2010." ScholarWorks @ UVM, 2011. http://scholarworks.uvm.edu/graddis/107.

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Lake whitefish (Coregonus clupeaformis), in the family Salmonidae, is a coldwater species that is widely distributed in North America. Throughout their range, whitefish support one of the most economically valuable freshwater fisheries and were also commercially fished in Lake Champlain. My goals were to quantify seasonal diet, determine temporal and spatial changes in larval abundance, evaluate biological parameters (size and age structure, sex composition, growth, condition, energy density, and fecundity), and determine if the introduction of zebra mussels (Dreissena polymorpha) to Lake Champlain in 1993 had similar affects on the whitefish population as seen in many of the Great Lakes. Whitefish were collected year-round using gillnets and bottom trawls. Diet was quantified seasonally. Temporal and spatial changes in larval abundance were determined by ichthyoplankton net catches. A comparison of scales, fin rays, and otoliths indicated that otoliths provided the lowest bias and highest precision. Age estimation using otoliths generated a wider range of ages and greater number of age classes when compared with scales and fin rays and therefore age and growth were determined using otolith age estimates. Growth parameters of the entire main lake population were estimated using the von Bertalanffy growth model (K = 0.20; L∞ = 598 mm), mean condition using Fulton’s K condition factor (K = 1.05) and by determining energy density, and fecundity using the gonadosomatic index (GSI = 13.9). Larval whitefish were abundant throughout much of the main lake, but absent in Missisquoi Bay and rare in Larabee’s Point, the historic commercially fished locations. Diet varied seasonally; whitefish fed primarily on large numbers of fish eggs in the spring and transitioned to foraging on mysids in the summer and gastropods in the fall and winter. Surprisingly, zebra mussels made up less than 1% of the diet and appeared in less than 10% of the stomachs analyzed, despite being abundant in the benthos. Biological parameters (size and age structure, sex composition, growth, condition, energy density, and fecundity) of whitefish in Lake Champlain were typical of an unexploited population, with multiple length and age classes represented. Condition was high and representative of a diet with high energy content. Whitefish in Lake Champlain had similar high energy density to those in Lake Erie, where declines in whitefish condition were not associated with dreissenid invasions, and had greater mean energy density than whitefish in lakes Michigan, Huron, and Ontario. I concluded that the current whitefish population in the main lake of Lake Champlain is typical of an unexploited population. However, whitefish apparently no longer use Missisquoi Bay and Larabee’s Point for spawning, most likely because of human alteration of habitat conditions. The high condition factor and energy density of whitefish in Lake Champlain, in contrast to the Great Lakes, is probably a result of their ability to attain sufficient energy sources from an intact native forage base.

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47

Corradin, Lisa M. "Recruitment and growth dynamics of lake trout in western Lake Superior /." Link to Abstract, 2004. http://epapers.uwsp.edu/abstracts/2004/Corradin.pdf.

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48

Norris, Paula Sue. "A Survey of Landowner Attitudes Toward the Construction of Lake Ray Roberts." Thesis, University of North Texas, 1991. https://digital.library.unt.edu/ark:/67531/metadc500932/.

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Documentation of social impacts resulting from the construction of Lake Ray Roberts is to be incorporated into a two year post-impoundment study. Research objectives are to: 1) locate current residences of landowners and previous landowners who were displaced; 2) determine social impacts resulting from construction of Lake Ray Roberts; 3) document degree of satisfaction with current living conditions; 4) document landowners' degree of satisfaction associated with COE negotiations; 5) document landowners' observations. Landowners were identified by telephone and sent a mail-back questionnaire. Respondents were generally happy with current residences and communities. While courtesy and sufficient information were provided by the COE, respondents would have preferred for property settlements to be more consistent and timely.

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49

Winston, Barry S. "Satellite Remote Sensing of Lake Ice Meltout Patterns Near Barrow, Alaska." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1276980832.

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50

Scheuerell, Mark David. "Environmental drivers of spatial and temporal variability in lakes /." Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/5144.

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Dissertations / Theses on the topic 'Lake'

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