The microscopic dimension of paleoclimate in the EPICA-DML(Antarctica) deep ice core
by Aneta Florentina Nedelcu
Date of Examination:2011-03-16
Date of issue:2013-03-12
Advisor:Prof. Dr. Werner F. Kuhs
Referee:Prof. Dr. Gerhard Wörner
Referee:Dr. Sergio H. Faria
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Description:dissertation
Abstract
English
The present work is divided into two main parts: the introductory half and the experimental chapter. Chapter 1 starts with the brief presentation of the scientific project that facilitated the development of the thesis, then presents a historical survey of the early expeditions towards and in Antarctica, just to reach to the basic geological aspects relevant for the second part of the work, and to end with some glaciological aspects worth of being noticed in the context of the thesis. The third section describes the basic Antarctic meteorology, focus on Dronning Maud Land region, while the forth subchapter tells only a few stories about the EPICA-DML ice core. The last part of Chapter 1 wanted to be a kind of ‘encyclopedia’ of what can be found as trapped in polar ice; it resulted in some useful but subjective base for the understanding and interpretation of the results presented in the second half of the thesis. Chapter 2 deals with the presentation of the original results after the employed methods are briefly described. Outcomes from optical microscopy investigations, a few SEM-EDX analyses, and mostly from the first Raman analyses on microinclusions existent in EDML ice, (included as Appendixes), lead to the following conclusions (Chapter 3): -secondary microinclusions developed in polar ice after its extraction, due to structure relaxation, contain fractionated air enriched in oxygen, O2 -the nitrogen to oxygen (N2/O2) ratio for the investigated relaxation microinclusions took values between 0.3 and 2 -microinclusions containing soluble salts, may exist as solids or as liquid solutions, if their eutectic temperature permits or if they are associated with other substances, like acids -hardly soluble microinclusions are mainly silicates and/or silica, and to a lesser degree Ti containing compounds and they are enriched in less clear ice (cloudy ice) -a number of microinclusions, which could have been formed in the polar atmosphere or in the firn/ice matrix, contain more than one compound (either two different sulfates or a Si compound and sulfate)
Keywords: Raman spectroscopy; polar ice; microinclusions; glaciochemisry