Heinrich Events in North Atlantic Sediments: CT Scanning and Other Analyses.

The first objective of this thesis is to present a new method for counting ice rafted debris (IRD) in ocean cores, using computerised tomography (CT) scanning and the powerful image processing software package FIJI and its associated plugin BoneJ (Doube et al., 2010). This is the first time such a m...

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Main Author: Danino, Steffan
Format: Thesis
Language:English
Published: Apollo - University of Cambridge Repository 2015
Subjects:
Online Access:https://dx.doi.org/10.17863/cam.8753
https://www.repository.cam.ac.uk/handle/1810/263411
id ftdatacite:10.17863/cam.8753
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spelling ftdatacite:10.17863/cam.8753 2023-05-15T17:32:38+02:00 Heinrich Events in North Atlantic Sediments: CT Scanning and Other Analyses. Danino, Steffan 2015 https://dx.doi.org/10.17863/cam.8753 https://www.repository.cam.ac.uk/handle/1810/263411 en eng Apollo - University of Cambridge Repository All Rights Reserved https://www.rioxx.net/licenses/all-rights-reserved/ Text Thesis article-journal ScholarlyArticle 2015 ftdatacite https://doi.org/10.17863/cam.8753 2021-11-05T12:55:41Z The first objective of this thesis is to present a new method for counting ice rafted debris (IRD) in ocean cores, using computerised tomography (CT) scanning and the powerful image processing software package FIJI and its associated plugin BoneJ (Doube et al., 2010). This is the first time such a method has been demonstrated. CT scans have been carried out on North Atlantic sediment cores from Integrated Ocean Drilling Program (IODP) site U1308 (49°52'39.9"N, 24°14'17.2"W; the site used by Hodell et al., 2008), containing Heinrich events H1, H4 and H16. Additionally, a detailed manual IRD count has been carried out on samples of a core showing H4 to compare the efficacy of this computerised method, and to show the viability of CT scanning as a method of counting IRD. Secondly, this thesis seeks to establish how H16 compares to the well studied H4, using high resolution X-ray fluorescence (XRF) scanning and CT scanning of both events. The magnitude of the two events is identified as well as the nature of the two IRD peaks seen over the course of H16. Thirdly, the findings of the thesis will be placed within a wider glaciological and geological context, and current theories regarding Heinrich events reviewed in light of them. In Chapter 2 of the thesis, the mechanisms involved in ice-rafting events are explained, followed by a review of current theories regarding Heinrich event forcing in Chapter 3. In Chapter 4 a detailed account of the methods used in the analysis of the cores from site U1308 is presented, in particular the development of ice rafted debris detection using CT scanning, the results from which are presented in Chapter 5. This is contrasted in Chapter 6 with previous methods of debris counting by sampling, to evaluate the use of CT scanning as a means of counting ice rafted debris. In Chapter 6, the CT scan data is also compared to the XRF scan data collected, and XRF data is discussed and compared to the literature in order to evaluate current theories concerning Heinrich events. Thesis North Atlantic DataCite Metadata Store (German National Library of Science and Technology)
institution Open Polar
collection DataCite Metadata Store (German National Library of Science and Technology)
op_collection_id ftdatacite
language English
description The first objective of this thesis is to present a new method for counting ice rafted debris (IRD) in ocean cores, using computerised tomography (CT) scanning and the powerful image processing software package FIJI and its associated plugin BoneJ (Doube et al., 2010). This is the first time such a method has been demonstrated. CT scans have been carried out on North Atlantic sediment cores from Integrated Ocean Drilling Program (IODP) site U1308 (49°52'39.9"N, 24°14'17.2"W; the site used by Hodell et al., 2008), containing Heinrich events H1, H4 and H16. Additionally, a detailed manual IRD count has been carried out on samples of a core showing H4 to compare the efficacy of this computerised method, and to show the viability of CT scanning as a method of counting IRD. Secondly, this thesis seeks to establish how H16 compares to the well studied H4, using high resolution X-ray fluorescence (XRF) scanning and CT scanning of both events. The magnitude of the two events is identified as well as the nature of the two IRD peaks seen over the course of H16. Thirdly, the findings of the thesis will be placed within a wider glaciological and geological context, and current theories regarding Heinrich events reviewed in light of them. In Chapter 2 of the thesis, the mechanisms involved in ice-rafting events are explained, followed by a review of current theories regarding Heinrich event forcing in Chapter 3. In Chapter 4 a detailed account of the methods used in the analysis of the cores from site U1308 is presented, in particular the development of ice rafted debris detection using CT scanning, the results from which are presented in Chapter 5. This is contrasted in Chapter 6 with previous methods of debris counting by sampling, to evaluate the use of CT scanning as a means of counting ice rafted debris. In Chapter 6, the CT scan data is also compared to the XRF scan data collected, and XRF data is discussed and compared to the literature in order to evaluate current theories concerning Heinrich events.
format Thesis
author Danino, Steffan
spellingShingle Danino, Steffan
Heinrich Events in North Atlantic Sediments: CT Scanning and Other Analyses.
author_facet Danino, Steffan
author_sort Danino, Steffan
title Heinrich Events in North Atlantic Sediments: CT Scanning and Other Analyses.
title_short Heinrich Events in North Atlantic Sediments: CT Scanning and Other Analyses.
title_full Heinrich Events in North Atlantic Sediments: CT Scanning and Other Analyses.
title_fullStr Heinrich Events in North Atlantic Sediments: CT Scanning and Other Analyses.
title_full_unstemmed Heinrich Events in North Atlantic Sediments: CT Scanning and Other Analyses.
title_sort heinrich events in north atlantic sediments: ct scanning and other analyses.
publisher Apollo - University of Cambridge Repository
publishDate 2015
url https://dx.doi.org/10.17863/cam.8753
https://www.repository.cam.ac.uk/handle/1810/263411
genre North Atlantic
genre_facet North Atlantic
op_rights All Rights Reserved
https://www.rioxx.net/licenses/all-rights-reserved/
op_doi https://doi.org/10.17863/cam.8753
_version_ 1766130839933943808