Title Information
Title
Development and Application of Lacustrine Alkenone Paleothermometry in Southwestern Greenland
Name: Personal
Name Part
D'Andrea, William J
Role
Role Term: Text
creator
Origin Information
Copyright Date
2009
Physical Description
Extent
xix, 208 p.
digitalOrigin
born digital
Note
Thesis (Ph.D. -- Brown University (2009)
Name: Personal
Name Part
Huang, Yongsong
Role
Role Term: Text
Director
Name: Personal
Name Part
Herbert, Timothy
Role
Role Term: Text
Reader
Name: Personal
Name Part
Russell, Jim
Role
Role Term: Text
Reader
Name: Personal
Name Part
Saal, Alberto
Role
Role Term: Text
Reader
Name: Personal
Name Part
Oppo, Delia
Role
Role Term: Text
Reader
Name: Corporate
Name Part
Brown University. Geological Sciences
Role
Role Term: Text
sponsor
Genre (aat)
theses
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.
Subject
Topic
alkenone
Subject
Topic
biomarker
Subject
Topic
climate
Subject
Topic
holocene
Subject
Topic
paleoclimate
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/831950")
Topic
Biochemical markers
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/980232")
Topic
Isotopes
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/864281")
Topic
Climatology
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/1353233")
Topic
Holocene Geologic Period
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/998940")
Topic
Limnology
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/1051364")
Topic
Paleoclimatology
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/1205290")
Geographic
Greenland
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20110926
Language
Language Term: Code (ISO639-2B)
eng
Language Term: Text
English
Identifier: DOI
10.7301/Z0765CJX
Access Condition: rights statement (href="http://rightsstatements.org/vocab/InC/1.0/")
In Copyright
Access Condition: restriction on access
Collection is open for research.
Type of Resource (primo)
dissertations