Antarctic ice-sheet expansions in the Middle Miocene and Pliocene
The ice sheet-climate model developed in this study describes the Antarctic ice sheet. It is forced by energy and mass balances and includes oxygen isotopes as a passive tracer.Simulating the Middle Miocene climate transition showed that a decrease in atmospheric CO2, crossing a threshold of about 4...
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Universität Bremen
2008
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Online Access: | https://media.suub.uni-bremen.de/handle/elib/2609 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000112917 |
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ftsubbremen:oai:media.suub.uni-bremen.de:Publications/elib/2609 2023-05-15T13:42:31+02:00 Antarctic ice-sheet expansions in the Middle Miocene and Pliocene Langebroek, Petra Schulz, Michael Tiedemann, Ralf 2008-12-12 application/pdf https://media.suub.uni-bremen.de/handle/elib/2609 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000112917 eng eng Universität Bremen FB5 Geowissenschaften https://media.suub.uni-bremen.de/handle/elib/2609 urn:nbn:de:gbv:46-diss000112917 info:eu-repo/semantics/openAccess Bitte wählen Sie eine Lizenz aus: (Unsere Empfehlung: CC-BY) CC-BY Antarctic ice sheet modeling CO2 insolation Middle Miocene 550 550 Earth sciences and geology ddc:550 Dissertation doctoralThesis 2008 ftsubbremen 2022-11-09T07:09:50Z The ice sheet-climate model developed in this study describes the Antarctic ice sheet. It is forced by energy and mass balances and includes oxygen isotopes as a passive tracer.Simulating the Middle Miocene climate transition showed that a decrease in atmospheric CO2, crossing a threshold of about 400 ppm, followed by a minimum in summer insolation, initiated a large-scale ice-sheet expansion.Experiments further confirm the validity of the often applied ratio of a 1 permille increase in oxygen-isotope composition for a global sea-level lowering of 100 m. For the mid-Pliocene, the ice-sheet component was forced by temperatures and accumulation rates from a comprehensive climate model. The closure of the Panamanian gateway in the mid-Pliocene was found to induce an intensification of the meridional circulation with a cooling over Antarctica as result. In turn, this cooling forced the Antarctic ice-sheet to expand. From the examples discussed in this study it can be concluded that changes in temperature, due to atmospheric CO2 as well as due to tectonic forcing, have a large impact on the extent of the Antarctic ice sheet. Doctoral or Postdoctoral Thesis Antarc* Antarctic Antarctica Ice Sheet Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) Antarctic The Antarctic |
institution |
Open Polar |
collection |
Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) |
op_collection_id |
ftsubbremen |
language |
English |
topic |
Antarctic ice sheet modeling CO2 insolation Middle Miocene 550 550 Earth sciences and geology ddc:550 |
spellingShingle |
Antarctic ice sheet modeling CO2 insolation Middle Miocene 550 550 Earth sciences and geology ddc:550 Langebroek, Petra Antarctic ice-sheet expansions in the Middle Miocene and Pliocene |
topic_facet |
Antarctic ice sheet modeling CO2 insolation Middle Miocene 550 550 Earth sciences and geology ddc:550 |
description |
The ice sheet-climate model developed in this study describes the Antarctic ice sheet. It is forced by energy and mass balances and includes oxygen isotopes as a passive tracer.Simulating the Middle Miocene climate transition showed that a decrease in atmospheric CO2, crossing a threshold of about 400 ppm, followed by a minimum in summer insolation, initiated a large-scale ice-sheet expansion.Experiments further confirm the validity of the often applied ratio of a 1 permille increase in oxygen-isotope composition for a global sea-level lowering of 100 m. For the mid-Pliocene, the ice-sheet component was forced by temperatures and accumulation rates from a comprehensive climate model. The closure of the Panamanian gateway in the mid-Pliocene was found to induce an intensification of the meridional circulation with a cooling over Antarctica as result. In turn, this cooling forced the Antarctic ice-sheet to expand. From the examples discussed in this study it can be concluded that changes in temperature, due to atmospheric CO2 as well as due to tectonic forcing, have a large impact on the extent of the Antarctic ice sheet. |
author2 |
Schulz, Michael Tiedemann, Ralf |
format |
Doctoral or Postdoctoral Thesis |
author |
Langebroek, Petra |
author_facet |
Langebroek, Petra |
author_sort |
Langebroek, Petra |
title |
Antarctic ice-sheet expansions in the Middle Miocene and Pliocene |
title_short |
Antarctic ice-sheet expansions in the Middle Miocene and Pliocene |
title_full |
Antarctic ice-sheet expansions in the Middle Miocene and Pliocene |
title_fullStr |
Antarctic ice-sheet expansions in the Middle Miocene and Pliocene |
title_full_unstemmed |
Antarctic ice-sheet expansions in the Middle Miocene and Pliocene |
title_sort |
antarctic ice-sheet expansions in the middle miocene and pliocene |
publisher |
Universität Bremen |
publishDate |
2008 |
url |
https://media.suub.uni-bremen.de/handle/elib/2609 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000112917 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet |
op_relation |
https://media.suub.uni-bremen.de/handle/elib/2609 urn:nbn:de:gbv:46-diss000112917 |
op_rights |
info:eu-repo/semantics/openAccess Bitte wählen Sie eine Lizenz aus: (Unsere Empfehlung: CC-BY) |
op_rightsnorm |
CC-BY |
_version_ |
1766168736311541760 |