Ocean climate dynamics of a millenial-scale Antarctic climate fluctuation during Termination V
Lead Research Organisation:
University of Southampton
Department Name: Sch of Ocean and Earth Science
Abstract
Rapid climate change is highly topical given the rising public awareness of the issues around and implications of global warming. The rapid change from ice ages to warmer periods associated with the melting of ice and rapid rise of sea level are especially dynamic periods. Their relevance is particularly significant given possible future scenarios that include melting of the south polar or Greenland ice caps. This project aims to study the most intense deglaciation of the last several million years in order to identify the links between changes at the opposing polar regions. Recent research has suggested that change in the north and south is linked and our project will shed further light on this model that may increase our understanding of the global linking of climate change processes.
Organisations
People |
ORCID iD |
| Alan Kemp (Principal Investigator) | |
| Eelco Rohling (Co-Investigator) |
Publications
Kemp A
(2010)
Migration of the Antarctic Polar Front through the mid-Pleistocene transition: evidence and climatic implications
in Quaternary Science Reviews
Kemp A
(2018)
The case of the diatoms and the muddled mandalas: Time to recognize diatom adaptations to stratified waters
in Progress in Oceanography
Rohling E
(2010)
Comparison between Holocene and Marine Isotope Stage-11 sea-level histories
in Earth and Planetary Science Letters
| Description | The structure of a major rapid warming event during the deglaciation at Termination V (around 420,000 years ago) has been identified. This event is associated with migration of the main polar front that surrounds and thermally isolates the Antarctic continent. This separates warm waters, to the north from cold waters to the south. Floods of a warm water plankton (diatom algae) coincide with the arrival of other warm water species of foraminfera and calcareous nannofossils and an initial ice rafting event testifiying to an abrupt warming "overshoot" during deglaciation. This indicates a short lived (ca. 3 kiloyear) episode where the major oceanic fronts that surround Antarctica must have collapsed. Stable oxygen isotope analysis confirms abrupt warming and melting at this time and appear to be coherent with the temperature signal recorded in the Antarctic contentintal ice sheet (the EPICA ice core) at this time. Following this episode there appears to have been a similarly abrupt "cold reversal" indicated by stable isotopes and abrupt decline of the warm water microfossil indicators. More broadly, this research shows evidence of the similarity of glacial termination V to termination I (the last deglaciation at around 18,000 years ago) at a time when there is some controversy as to how much glacial terminations differ or present a uniform response of the earth system, ocean and cryosphere to abrupt change. The research therefore appears to support the "bipolar seasaw" behavior of Atlantic thermohaline circulation (the "conveyor") during deglaciation. The main objectives concerning coherency of the marine record produced and the EPICA ice core temperature variations and the validation of the bipolar seasaw mechanism are therefore substantively attained. |
| Exploitation Route | The results may be used to improve models of Earth System behaviour and provide a case study of a rapid climate change event. |
| Sectors | Education,Environment |