An insight into the climate and oceanographic regime of the southwest Pacific: middle Eocene variability on orbital timescales using a multiproxy approach
An insight into the climate and oceanographic regime of the southwest Pacific: middle Eocene variability on orbital timescales using a multiproxy approach
The southwest Pacific Ocean has yielded palaeotemperature reconstructions for the middle Eocene (mid-Eocene) (48-38 Ma) that are comparable to those from the equatorial regions. Current generation of fully coupled climate models are able to reconcile high temperatures with extreme radiative or greenhouse forcing, however, struggle to reproduce the low meridional temperature gradients. The models appear to lack crucial high latitude feedback mechanisms or accurate boundary conditions that may amplify climate sensitivity at the poles. This is significant to elucidate as atmospheric CO2 concentrations and global warming will reach levels of the Eocene if unabated rates of fossil fuel consumption continue. The proxy-model mismatch highlights an uncertainty in our understanding of how climate conditions and dynamics varied in past warm worlds. This study aims to gain further insight into climate variability on orbital timescales, as well as the environmental response to these forcing. Furthermore, through identifying the dominant cycle, the oceanographic regimes were investigated. Data was acquired using a multiproxy approach on ocean cores from ODP Leg 189 Site 1172, on the East Tasman Plateau. A gap was filled in the inorganic geochemical composition record, using X-ray fluorescence core scanning, within which orbital cycles were identified. A higher resolution marine palynology assemblage, mostly dinoflagellate cysts, and a sea surface temperature (SST) record was then established for two intervals. One in the first cooling phase following the Early Eocene Climatic Optimum (EECO) (~46.5-47.5 Ma), and the second prior to the …
Hollingsworth, Emily
3c2fb70d-74ba-495a-910b-51220df30892
2020
Hollingsworth, Emily
3c2fb70d-74ba-495a-910b-51220df30892
Hollingsworth, Emily
(2020)
An insight into the climate and oceanographic regime of the southwest Pacific: middle Eocene variability on orbital timescales using a multiproxy approach.
Masters Thesis.
Record type:
Thesis
(Masters)
Abstract
The southwest Pacific Ocean has yielded palaeotemperature reconstructions for the middle Eocene (mid-Eocene) (48-38 Ma) that are comparable to those from the equatorial regions. Current generation of fully coupled climate models are able to reconcile high temperatures with extreme radiative or greenhouse forcing, however, struggle to reproduce the low meridional temperature gradients. The models appear to lack crucial high latitude feedback mechanisms or accurate boundary conditions that may amplify climate sensitivity at the poles. This is significant to elucidate as atmospheric CO2 concentrations and global warming will reach levels of the Eocene if unabated rates of fossil fuel consumption continue. The proxy-model mismatch highlights an uncertainty in our understanding of how climate conditions and dynamics varied in past warm worlds. This study aims to gain further insight into climate variability on orbital timescales, as well as the environmental response to these forcing. Furthermore, through identifying the dominant cycle, the oceanographic regimes were investigated. Data was acquired using a multiproxy approach on ocean cores from ODP Leg 189 Site 1172, on the East Tasman Plateau. A gap was filled in the inorganic geochemical composition record, using X-ray fluorescence core scanning, within which orbital cycles were identified. A higher resolution marine palynology assemblage, mostly dinoflagellate cysts, and a sea surface temperature (SST) record was then established for two intervals. One in the first cooling phase following the Early Eocene Climatic Optimum (EECO) (~46.5-47.5 Ma), and the second prior to the …
This record has no associated files available for download.
More information
Published date: 2020
Identifiers
Local EPrints ID: 510375
URI: http://eprints.soton.ac.uk/id/eprint/510375
PURE UUID: 89522a50-5738-4774-9fbd-6e12480d1f17
Catalogue record
Date deposited: 27 Mar 2026 18:07
Last modified: 28 Mar 2026 03:18
Export record
Contributors
Author:
Emily Hollingsworth
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics