<mods:mods xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:METS="http://www.loc.gov/METS/" ID="etd164" xsi:schemaLocation="http://www.loc.gov/mods/v3  http://www.loc.gov/standards/mods/v3/mods-3-2.xsd">
          <mods:titleInfo>
            <mods:title>Development and Application of Lacustrine 
Alkenone Paleothermometry in Southwestern Greenland</mods:title>
          </mods:titleInfo>
          <mods:name type="personal">
            <mods:namePart>D'Andrea, William J</mods:namePart>
            <mods:role>
              <mods:roleTerm type="text">creator</mods:roleTerm>
            </mods:role>
          </mods:name>
          <mods:originInfo>
            <mods:copyrightDate>2009</mods:copyrightDate>
          </mods:originInfo>
          <mods:physicalDescription>
            <mods:extent>xix, 208 p.</mods:extent>
            <mods:digitalOrigin>born digital</mods:digitalOrigin>
          </mods:physicalDescription>
          <mods:note>Thesis (Ph.D. -- Brown University (2009)</mods:note>
          <mods:name type="personal">
            <mods:namePart>Huang, Yongsong</mods:namePart>
            <mods:role>
              <mods:roleTerm type="text">Director</mods:roleTerm>
            </mods:role>
          </mods:name>
          <mods:name type="personal">
            <mods:namePart>Herbert, Timothy</mods:namePart>
            <mods:role>
              <mods:roleTerm type="text">Reader</mods:roleTerm>
            </mods:role>
          </mods:name>
          <mods:name type="personal">
            <mods:namePart>Russell, Jim</mods:namePart>
            <mods:role>
              <mods:roleTerm type="text">Reader</mods:roleTerm>
            </mods:role>
          </mods:name>
          <mods:name type="personal">
            <mods:namePart>Saal, Alberto</mods:namePart>
            <mods:role>
              <mods:roleTerm type="text">Reader</mods:roleTerm>
            </mods:role>
          </mods:name>
          <mods:name type="personal">
            <mods:namePart>Oppo, Delia</mods:namePart>
            <mods:role>
              <mods:roleTerm type="text">Reader</mods:roleTerm>
            </mods:role>
          </mods:name>
          <mods:name type="corporate">
            <mods:namePart>Brown University. Geological 
Sciences</mods:namePart>
            <mods:role>
              <mods:roleTerm type="text">sponsor</mods:roleTerm>
            </mods:role>
          </mods:name>
          <mods:genre authority="aat">theses</mods:genre>
          <mods:abstract>Alkenones are lipids produced by certain 
haptophyte algae and are excellent sensors of temperature change. This 
dissertation investigates the stable isotopic and organic geochemical 
aspects of alkenones from brackish Greenlandic lakes and develops their 
use as a paleothermometer. Alkenones are reported from brackish lakes 
near Kangerlussuaq, Greenland and their distribution and δ13C 
values are examined. Results indicate that 1) the Greenland alkenones 
are most similar to those from lakes in Germany and Austria, suggesting 
a common producer organism and 2) alkenone producers must either 
fractionate CO2 to a greater extent than other algae or access a 
13C-depleted carbon source. Haptophyte-specific ribosomal DNA (rDNA) 
sequences from Greenlandic lake sediment and water samples are compared 
with rDNA of known haptophytes, and demonstrate that the Greenlandic 
alkenone producers represent a new taxon of haptophyte algae, and that 
all Greenlandic lakes of the study contain the same haptophytes. A new 
liquid chromatographic procedure is reported for separating alkenones 
having the same carbon number but different degrees of unsaturation for 
the purpose of compound-specific hydrogen isotopic analysis. δD 
measurements on individual alkenones indicate that hydrogen isotopic 
composition differs according to the degree of alkenone unsaturation. 
This suggests it is preferable to make δD measurements on 
individual alkenones, due to possible temperature-related effects on 
"pooled" δD values and because measurements on individual alkenones 
provide improved precision and accuracy. Temperature variability for the 
past 6,000 years in Kangerlussuaq, Greenland is reconstructed by 
applying alkenone paleotherrmometry to sediment cores from two lakes in 
the region. Temperature in the Kangerlussuaq region appears to have been 
controlled by changes in Meridional Overturning Circulation and the 
extent of the North Polar Vortex on millennial timescales, while being 
driven by variability in the North Atlantic Oscillation over centennial 
timescales. The timing of major changes in Paleo-Eskimo, Norse and Inuit 
occupation of Southwestern Greenland coincide with episodes of abrupt 
temperature change revealed by the alkenone record, indicating that 
climatic and environmental changes played a fundamental role in the 
patterns of human migration in Greenland over the past 4,500 
years.</mods:abstract>
          <mods:subject>
            <mods:topic>alkenone</mods:topic>
          </mods:subject>
          <mods:subject>
            <mods:topic>biomarker</mods:topic>
          </mods:subject>
          <mods:subject>
            <mods:topic>climate</mods:topic>
          </mods:subject>
          <mods:subject>
            <mods:topic>holocene</mods:topic>
          </mods:subject>
          <mods:subject>
            <mods:topic>paleoclimate</mods:topic>
          </mods:subject>
          <mods:subject authority="FAST" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/831950"><mods:topic>Biochemical markers</mods:topic></mods:subject><mods:subject authority="FAST" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/980232"><mods:topic>Isotopes</mods:topic></mods:subject><mods:subject authority="FAST" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/864281"><mods:topic>Climatology</mods:topic></mods:subject><mods:subject authority="FAST" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/1353233"><mods:topic>Holocene Geologic Period</mods:topic></mods:subject><mods:subject authority="FAST" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/998940"><mods:topic>Limnology</mods:topic></mods:subject><mods:subject authority="FAST" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/1051364"><mods:topic>Paleoclimatology</mods:topic></mods:subject><mods:subject authority="FAST" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/1205290"><mods:geographic>Greenland</mods:geographic></mods:subject><mods:recordInfo>
            <mods:recordContentSource authority="marcorg">RPB</mods:recordContentSource>
            <mods:recordCreationDate encoding="iso8601">20110926</mods:recordCreationDate>
          </mods:recordInfo>
        <mods:language><mods:languageTerm type="code" authority="iso639-2b">eng</mods:languageTerm><mods:languageTerm type="text">English</mods:languageTerm></mods:language><mods:identifier type="doi">10.7301/Z0765CJX</mods:identifier><mods:accessCondition type="rights statement" xlink:href="http://rightsstatements.org/vocab/InC/1.0/">In Copyright</mods:accessCondition><mods:accessCondition type="restriction on access">Collection is open for research.</mods:accessCondition><mods:typeOfResource authority="primo">dissertations</mods:typeOfResource></mods:mods>