Principal components analysis as a tool for Quaternary paleoclimatic research
Conference
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· Geological Society of America, Abstracts with Programs; (United States)
OSTI ID:5770650
- Univ. of Colorado, Boulder, CO (United States). Dept. of Geological Sciences
Nine small lakes on southeast Baffin Island, NWT, Canada, were cored and the sediments retrieved were analyzed for sediment size and composition, magnetic susceptibility, sediment geochemistry, organic matter content, and carbon isotopic composition. Age control was obtained from 85 AMS radiocarbon dates. in total, 1,847 measurements were made on twelve cores. The size of the data set precluded the use of visual analysis of the trends within each of the variable data sets. The method used to deconvolute the paleoenvironmental signal was one of principal components analysis and regression. Principal components analysis was carried out on the entire data set to determine which variables caused most of the variance within the overall signal. This showed that three principal components axes (PCAs) could account for 79% of the total variance within the data set. For each PCA, the closest correlated variable was chosen (sand content, total organic matter content, and sedimentation rate) and for each lake core, this variable was regressed against time. Residuals from the regression trend were then derived and normalized to a Z score. Z scores for each variable were plotted against age. Then, within 500 year timeslots, the median residual Z score was determined. This gave a stepped record of residuals throughout the Holocene and indicated periods of significant environmental change within the lakes' watersheds. Comparing this to previously obtained pollen and diatom records from the same area showed similarity and also illustrated important local differences.
- OSTI ID:
- 5770650
- Report Number(s):
- CONF-921058--
- Conference Information:
- Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 24:7
- Country of Publication:
- United States
- Language:
- English
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Journal Article
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Mon Mar 31 23:00:00 EST 1997
· Environmental Toxicology and Chemistry
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OSTI ID:514524
Late Holocene history of Tokotan Lake (Kuril Archipelago, Russian Far East): The use of lacustrine records for paleoclimatic reconstructions from geologically dynamic settings
Journal Article
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Sun Jun 28 20:00:00 EDT 2020
· Quaternary International
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OSTI ID:1670541