Refinement and application of a new paleotemperature estimation technique
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 1990 A recently developed technique for determining past sea surface temperatures (SST), based on an analysis of...
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Massachusetts Institute of Technology and Woods Hole Oceanographic Institution
1990
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/5409 2023-05-15T17:41:42+02:00 Refinement and application of a new paleotemperature estimation technique Sikes, Elisabeth L. Equatorial Atlantic Northeast Atlantic 1990-06 application/pdf https://hdl.handle.net/1912/5409 en_US eng Massachusetts Institute of Technology and Woods Hole Oceanographic Institution WHOI Theses https://hdl.handle.net/1912/5409 doi:10.1575/1912/5409 doi:10.1575/1912/5409 Ocean-atmosphere interaction Paleothermometry Thesis 1990 ftwhoas https://doi.org/10.1575/1912/5409 2022-05-28T22:58:40Z Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 1990 A recently developed technique for determining past sea surface temperatures (SST), based on an analysis of the unsaturation ratio of long chain C37 methyl alkenones (Uk37) produced by Prymnesiophyceae phytoplankton, has been applied to late Quaternary sediment cores. Previous studies have shown that the Uk37 ratio of these alkenones is linearly proportional to the sea-water temperature in which the plankton grow, both in culture and water column samples. Furthermore, a reasonable correlation has been found between open ocean paleo-SST estimates based on Uk37 values and those derived from δ180, for the period spanning approximately the last 100,000 years (Brassell, 1986b). These results indicate this technique has potential for determining paleo-SST from analysis of alkenones extracted from marine sediments. In order to apply the Uk37 method quantitatively, it is necessary to calibrate the method for sediment samples, and to assess how well the alkenones maintain their temperature signal under some common conditions of sediment deposition and sample handling. It is also necessary to determine the method's usefulness downcore, that is, back in time, by comparing it to established methods. This study examined the effect on Uk37 of conditions that cause dissolution of carbonates in the sediment, and methods of storage and 'sample handling. These are two problems that must be resolved before the method can be applied rigorously and quantitatively to sediments for paleotemperature estimations. A comparison of duplicate samples collected and stored frozen versus those stored at room temperature for up to four years showed no resolvable differences in Uk37. Laboratory experiments of carbonate dissolution indicated there is no effect on Uk37 values under the acidic conditions that dissolve carbonates. Initial field results ... Thesis Northeast Atlantic Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Woods Hole, MA |
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Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
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language |
English |
topic |
Ocean-atmosphere interaction Paleothermometry |
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Ocean-atmosphere interaction Paleothermometry Sikes, Elisabeth L. Refinement and application of a new paleotemperature estimation technique |
topic_facet |
Ocean-atmosphere interaction Paleothermometry |
description |
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 1990 A recently developed technique for determining past sea surface temperatures (SST), based on an analysis of the unsaturation ratio of long chain C37 methyl alkenones (Uk37) produced by Prymnesiophyceae phytoplankton, has been applied to late Quaternary sediment cores. Previous studies have shown that the Uk37 ratio of these alkenones is linearly proportional to the sea-water temperature in which the plankton grow, both in culture and water column samples. Furthermore, a reasonable correlation has been found between open ocean paleo-SST estimates based on Uk37 values and those derived from δ180, for the period spanning approximately the last 100,000 years (Brassell, 1986b). These results indicate this technique has potential for determining paleo-SST from analysis of alkenones extracted from marine sediments. In order to apply the Uk37 method quantitatively, it is necessary to calibrate the method for sediment samples, and to assess how well the alkenones maintain their temperature signal under some common conditions of sediment deposition and sample handling. It is also necessary to determine the method's usefulness downcore, that is, back in time, by comparing it to established methods. This study examined the effect on Uk37 of conditions that cause dissolution of carbonates in the sediment, and methods of storage and 'sample handling. These are two problems that must be resolved before the method can be applied rigorously and quantitatively to sediments for paleotemperature estimations. A comparison of duplicate samples collected and stored frozen versus those stored at room temperature for up to four years showed no resolvable differences in Uk37. Laboratory experiments of carbonate dissolution indicated there is no effect on Uk37 values under the acidic conditions that dissolve carbonates. Initial field results ... |
format |
Thesis |
author |
Sikes, Elisabeth L. |
author_facet |
Sikes, Elisabeth L. |
author_sort |
Sikes, Elisabeth L. |
title |
Refinement and application of a new paleotemperature estimation technique |
title_short |
Refinement and application of a new paleotemperature estimation technique |
title_full |
Refinement and application of a new paleotemperature estimation technique |
title_fullStr |
Refinement and application of a new paleotemperature estimation technique |
title_full_unstemmed |
Refinement and application of a new paleotemperature estimation technique |
title_sort |
refinement and application of a new paleotemperature estimation technique |
publisher |
Massachusetts Institute of Technology and Woods Hole Oceanographic Institution |
publishDate |
1990 |
url |
https://hdl.handle.net/1912/5409 |
op_coverage |
Equatorial Atlantic Northeast Atlantic |
genre |
Northeast Atlantic |
genre_facet |
Northeast Atlantic |
op_source |
doi:10.1575/1912/5409 |
op_relation |
WHOI Theses https://hdl.handle.net/1912/5409 doi:10.1575/1912/5409 |
op_doi |
https://doi.org/10.1575/1912/5409 |
op_publisher_place |
Woods Hole, MA |
_version_ |
1766143399778320384 |