Ocean and Terrestrial Response to a Pleistocene Warm Interglacial (MIS11) as Revealed by Pollen and Dinoflagellates from Marine Sediment Cores, South Island, New Zealand

• Main Author: Prebble, Joseph Graham
• Format: Thesis
• Language: unknown
• Published: 2012
• Subjects: Earth Sciences not elsewhere classified; Dinoflagellate; Marine isotope stage II; Transfer function; School: Antarctic Research Centre; 049999 Earth Sciences not elsewhere classified; Marsden: 260113 Palynology; Marsden: 260401 Biological Oceanography; Degree Discipline: Geology; Degree Level: Doctoral; Degree Name: Doctor of Philosophy; Antarctic; Pacific; New Zealand; Marsden; Antarc*
• Online Access: https://doi.org/10.26686/wgtn.17003179; https://figshare.com/articles/thesis/Ocean_and_Terrestrial_Response_to_a_Pleistocene_Warm_Interglacial_MIS11_as_Revealed_by_Pollen_and_Dinoflagellates_from_Marine_Sediment_Cores_South_Island_New_Zealand/17003179

The response of the surface ocean and terrestrial climate in the New Zealand region to interglacial Marine Isotope Stage (MIS) 11 (423-380ka) is documented, using assemblages of fossilised marine algae (dinoflagellate cysts, or dinocysts) and spores/pollen from terrestrial plants, analysed from marine sediment cores. This work is underpinned by studies on the modern distribution of dinocysts, factors that influence their accumulation in marine sediment, and the use of dinocyst assemblages to quantify past sea surface temperature (SST). In the first of the modern-process studies, a dataset of modern sea-floor dinocyst assemblages from the Southern Hemisphere is collated, including new observations from the SW Pacific. Variations in the assemblages are related to environmental gradients. Cluster analysis reveals distinct biogeographic assemblage zones, individual taxa indicative of specific water masses are identified, while ordination of the databases indicates that the assemblages vary most with changes in SST. A second modern process study reports on the dinocyst assemblages from two time-incremental sediment traps (3 years of data) moored north and south of the Subtropical Front in the ocean east of New Zealand. This study provides observations of seasonal and inter-annual variability of dinocyst flux to the deep sea, which are used to identify possible biases in the sea-floor dinocyst assemblages. Observations from these first two studies are used in a systematic analysis of the strengths and weakness of using dinocyst assemblages to quantify SST in the SW Pacific. The best transfer function performance achieved was a root mean squared error of 1.47˚C, for an artificial neural network model, and the benefits in considering a range of model results are also established. Fossil records that document the oceanographic and terrestrial response to MIS11 are developed from two areas around New Zealand; (i) dinocysts assemblages are collected from the east Tasman Sea, from giant piston cores MD06-2987, -2988, and ...