Evolution of Antarctic Tabular Icebergs
The aim of this study was to investigate and quantify the role of the various processes affecting a large tabular iceberg during a typical lifecycle from calving to final decay. The thesis comprises three publications, each addressing a different aspect of the evolution of the tabular iceberg A-38B,...
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Universität Bremen
2009
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ftsubbremen:oai:media.suub.uni-bremen.de:Publications/elib/2679 2023-05-15T13:42:31+02:00 Evolution of Antarctic Tabular Icebergs Lebenszyklus Antarktischer Tafeleisberge Jansen, Daniela Miller, Heinrich Rack, Wolfgang Schulz, Michael 2009-06-22 application/pdf https://media.suub.uni-bremen.de/handle/elib/2679 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000114927 eng eng Universität Bremen FB5 Geowissenschaften https://media.suub.uni-bremen.de/handle/elib/2679 urn:nbn:de:gbv:46-diss000114927 info:eu-repo/semantics/openAccess Bitte wählen Sie eine Lizenz aus: (Unsere Empfehlung: CC-BY) CC-BY Tabular icebergs basal melting melt water transport ice generated tremor 550 550 Earth sciences and geology ddc:550 Dissertation doctoralThesis 2009 ftsubbremen 2022-11-09T07:09:51Z The aim of this study was to investigate and quantify the role of the various processes affecting a large tabular iceberg during a typical lifecycle from calving to final decay. The thesis comprises three publications, each addressing a different aspect of the evolution of the tabular iceberg A-38B, which calved from the Ronne Ice Shelf in October 1998.The first publication is focussed on inherent ice dynamics. To investigate the relevance of strain thinning to iceberg evolution, a numerical ice shelf model was adapted to the iceberg case. The interaction with atmosphere and ocean was included in the model, but parameterised in a simple way and estimated on the base of measurements and external model data. A five year simulation of the evolution of iceberg A 38B showed that basal melting is the primary cause for change of iceberg geometry during drift, whereas strain thinning is only relevant in cold areas where basal melting is low. Thus, the second part of the thesis concentrates on an improved basal melting approach. In the drift period between the entering of the Scotia Sea in March 2003 until the grounding near South Georgia in 2004, freeboard changes of A 38B were observed from analysis of ICESat Laser altimeter profiles. The iceberg melt rate was then fitted by varying the turbulent exchange parameters for temperature and salt at the ice ocean boundary to match the altimeter results. The data analysis indicated, that the iceberg passed through three melting regimes during its drift, each characterised by a different magnitude of turbulent exchange between iceberg and ocean depending on drift conditions. The analysis showed also that drifting tabular icebergs export more melt water to the Scotia Sea than previously assumed. To shed light onto the final stage of iceberg evolution, the third publication is focussed on the investigation of the grounding process of A-38B and related seismic events. The characteristic spectrograms of such signals probably represent excitation of elastic modes of the ice masses ... Doctoral or Postdoctoral Thesis Antarc* Antarctic Antarktis* Ice Shelf Iceberg* Ronne Ice Shelf Scotia Sea Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) Antarctic Ronne Ice Shelf ENVELOPE(-61.000,-61.000,-78.500,-78.500) Scotia Sea |
institution |
Open Polar |
collection |
Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) |
op_collection_id |
ftsubbremen |
language |
English |
topic |
Tabular icebergs basal melting melt water transport ice generated tremor 550 550 Earth sciences and geology ddc:550 |
spellingShingle |
Tabular icebergs basal melting melt water transport ice generated tremor 550 550 Earth sciences and geology ddc:550 Jansen, Daniela Evolution of Antarctic Tabular Icebergs |
topic_facet |
Tabular icebergs basal melting melt water transport ice generated tremor 550 550 Earth sciences and geology ddc:550 |
description |
The aim of this study was to investigate and quantify the role of the various processes affecting a large tabular iceberg during a typical lifecycle from calving to final decay. The thesis comprises three publications, each addressing a different aspect of the evolution of the tabular iceberg A-38B, which calved from the Ronne Ice Shelf in October 1998.The first publication is focussed on inherent ice dynamics. To investigate the relevance of strain thinning to iceberg evolution, a numerical ice shelf model was adapted to the iceberg case. The interaction with atmosphere and ocean was included in the model, but parameterised in a simple way and estimated on the base of measurements and external model data. A five year simulation of the evolution of iceberg A 38B showed that basal melting is the primary cause for change of iceberg geometry during drift, whereas strain thinning is only relevant in cold areas where basal melting is low. Thus, the second part of the thesis concentrates on an improved basal melting approach. In the drift period between the entering of the Scotia Sea in March 2003 until the grounding near South Georgia in 2004, freeboard changes of A 38B were observed from analysis of ICESat Laser altimeter profiles. The iceberg melt rate was then fitted by varying the turbulent exchange parameters for temperature and salt at the ice ocean boundary to match the altimeter results. The data analysis indicated, that the iceberg passed through three melting regimes during its drift, each characterised by a different magnitude of turbulent exchange between iceberg and ocean depending on drift conditions. The analysis showed also that drifting tabular icebergs export more melt water to the Scotia Sea than previously assumed. To shed light onto the final stage of iceberg evolution, the third publication is focussed on the investigation of the grounding process of A-38B and related seismic events. The characteristic spectrograms of such signals probably represent excitation of elastic modes of the ice masses ... |
author2 |
Miller, Heinrich Rack, Wolfgang Schulz, Michael |
format |
Doctoral or Postdoctoral Thesis |
author |
Jansen, Daniela |
author_facet |
Jansen, Daniela |
author_sort |
Jansen, Daniela |
title |
Evolution of Antarctic Tabular Icebergs |
title_short |
Evolution of Antarctic Tabular Icebergs |
title_full |
Evolution of Antarctic Tabular Icebergs |
title_fullStr |
Evolution of Antarctic Tabular Icebergs |
title_full_unstemmed |
Evolution of Antarctic Tabular Icebergs |
title_sort |
evolution of antarctic tabular icebergs |
publisher |
Universität Bremen |
publishDate |
2009 |
url |
https://media.suub.uni-bremen.de/handle/elib/2679 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000114927 |
long_lat |
ENVELOPE(-61.000,-61.000,-78.500,-78.500) |
geographic |
Antarctic Ronne Ice Shelf Scotia Sea |
geographic_facet |
Antarctic Ronne Ice Shelf Scotia Sea |
genre |
Antarc* Antarctic Antarktis* Ice Shelf Iceberg* Ronne Ice Shelf Scotia Sea |
genre_facet |
Antarc* Antarctic Antarktis* Ice Shelf Iceberg* Ronne Ice Shelf Scotia Sea |
op_relation |
https://media.suub.uni-bremen.de/handle/elib/2679 urn:nbn:de:gbv:46-diss000114927 |
op_rights |
info:eu-repo/semantics/openAccess Bitte wählen Sie eine Lizenz aus: (Unsere Empfehlung: CC-BY) |
op_rightsnorm |
CC-BY |
_version_ |
1766168744103510016 |