Late Holocene Climate Variability From Northern Gulf of Mexico Sediments: Merging Inorganic and Molecular Organic Geochemical Proxies
Accurate reconstruction of natural climate variability over the past millennium is critical for predicting responses to future climate change. In order to improve on current understanding of climate variability in the sub-tropical North Atlantic region over the past millennium, a rigorous study of G...
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ftunisfloridatam:oai:digitalcommons.usf.edu:etd-2747 2023-06-11T04:15:03+02:00 Late Holocene Climate Variability From Northern Gulf of Mexico Sediments: Merging Inorganic and Molecular Organic Geochemical Proxies Richey, Julie N 2010-07-12T07:00:00Z application/pdf https://digitalcommons.usf.edu/etd/1748 https://digitalcommons.usf.edu/context/etd/article/2747/viewcontent/.pdf unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/etd/1748 https://digitalcommons.usf.edu/context/etd/article/2747/viewcontent/.pdf default USF Tampa Graduate Theses and Dissertations little ice age medieval warm period foraminifera climate change holocene American Studies Arts and Humanities dissertation 2010 ftunisfloridatam 2023-05-04T18:00:34Z Accurate reconstruction of natural climate variability over the past millennium is critical for predicting responses to future climate change. In order to improve on current understanding of climate variability in the sub-tropical North Atlantic region over the past millennium, a rigorous study of Gulf of Mexico (GOM) sea surface temperature (SST) variability was conducted using both inorganic (foraminiferal Mg/Ca) and molecular organic (TEX86) geochemical proxies. In addition to generating multiple high-resolution climate records, the uncertainties of the SST proxies are rigorously assessed. There are 3 major research questions addressed: (1) What was the magnitude of GOM SST variability during the past 1,000 years, particularly during large-scale climate events such as the Little Ice Age (LIA) and the Medieval Warm Period (MWP). (2) Is the SST signal reproducible within the same sediment core, among different northern GOM basins, and using different geochemical SST proxies? (3) What are the ecological controls on the paleothermometers used to reconstruct SST variability in the GOM? Can differences in the ecology (i.e. seasonal distribution, depth habitat, etc.) of distinct paleothermometers be exploited to gain insight into changes in upper water column structure or seasonality in the GOM during the LIA and MWP? The major findings include: (1) The magnitude of temperature variability in the GOM over the past millennium is much larger than that estimated from Northern Hemisphere temperature reconstructions. The MWP (1400-900 yrs BP) was characterized by SSTs in the GOM that were similar to the modern SST, while the LIA (400-150 yrs BP) was marked by a series of multidecadal intervals that were 2-2.5°C cooler than modern. (2) This LIA cooling was replicated in the Mg/Ca-SST records from three different well-dated northern GOM basins (Pigmy, Garrison and Fisk Basins), as well as in two different geochemical proxies. (3) It is determined that foraminiferal test size has a significant effect on shell geochemistry. ... Doctoral or Postdoctoral Thesis North Atlantic Digital Commons University of South Florida (USF) |
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Digital Commons University of South Florida (USF) |
op_collection_id |
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topic |
little ice age medieval warm period foraminifera climate change holocene American Studies Arts and Humanities |
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little ice age medieval warm period foraminifera climate change holocene American Studies Arts and Humanities Richey, Julie N Late Holocene Climate Variability From Northern Gulf of Mexico Sediments: Merging Inorganic and Molecular Organic Geochemical Proxies |
topic_facet |
little ice age medieval warm period foraminifera climate change holocene American Studies Arts and Humanities |
description |
Accurate reconstruction of natural climate variability over the past millennium is critical for predicting responses to future climate change. In order to improve on current understanding of climate variability in the sub-tropical North Atlantic region over the past millennium, a rigorous study of Gulf of Mexico (GOM) sea surface temperature (SST) variability was conducted using both inorganic (foraminiferal Mg/Ca) and molecular organic (TEX86) geochemical proxies. In addition to generating multiple high-resolution climate records, the uncertainties of the SST proxies are rigorously assessed. There are 3 major research questions addressed: (1) What was the magnitude of GOM SST variability during the past 1,000 years, particularly during large-scale climate events such as the Little Ice Age (LIA) and the Medieval Warm Period (MWP). (2) Is the SST signal reproducible within the same sediment core, among different northern GOM basins, and using different geochemical SST proxies? (3) What are the ecological controls on the paleothermometers used to reconstruct SST variability in the GOM? Can differences in the ecology (i.e. seasonal distribution, depth habitat, etc.) of distinct paleothermometers be exploited to gain insight into changes in upper water column structure or seasonality in the GOM during the LIA and MWP? The major findings include: (1) The magnitude of temperature variability in the GOM over the past millennium is much larger than that estimated from Northern Hemisphere temperature reconstructions. The MWP (1400-900 yrs BP) was characterized by SSTs in the GOM that were similar to the modern SST, while the LIA (400-150 yrs BP) was marked by a series of multidecadal intervals that were 2-2.5°C cooler than modern. (2) This LIA cooling was replicated in the Mg/Ca-SST records from three different well-dated northern GOM basins (Pigmy, Garrison and Fisk Basins), as well as in two different geochemical proxies. (3) It is determined that foraminiferal test size has a significant effect on shell geochemistry. ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Richey, Julie N |
author_facet |
Richey, Julie N |
author_sort |
Richey, Julie N |
title |
Late Holocene Climate Variability From Northern Gulf of Mexico Sediments: Merging Inorganic and Molecular Organic Geochemical Proxies |
title_short |
Late Holocene Climate Variability From Northern Gulf of Mexico Sediments: Merging Inorganic and Molecular Organic Geochemical Proxies |
title_full |
Late Holocene Climate Variability From Northern Gulf of Mexico Sediments: Merging Inorganic and Molecular Organic Geochemical Proxies |
title_fullStr |
Late Holocene Climate Variability From Northern Gulf of Mexico Sediments: Merging Inorganic and Molecular Organic Geochemical Proxies |
title_full_unstemmed |
Late Holocene Climate Variability From Northern Gulf of Mexico Sediments: Merging Inorganic and Molecular Organic Geochemical Proxies |
title_sort |
late holocene climate variability from northern gulf of mexico sediments: merging inorganic and molecular organic geochemical proxies |
publisher |
Digital Commons @ University of South Florida |
publishDate |
2010 |
url |
https://digitalcommons.usf.edu/etd/1748 https://digitalcommons.usf.edu/context/etd/article/2747/viewcontent/.pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
USF Tampa Graduate Theses and Dissertations |
op_relation |
https://digitalcommons.usf.edu/etd/1748 https://digitalcommons.usf.edu/context/etd/article/2747/viewcontent/.pdf |
op_rights |
default |
_version_ |
1768371549437427712 |