Radiolarian-based Quaternary palaeoclimate reconstructions of the Sabrina Coast, East Antarctica

Date & time

12pm 27 March 2019

Location

Ringwood Room, J4

Speakers

Kelly-Anne Lawler (RSES/Macquarie)

Contacts

 Fiona Hibbert

Understanding past Southern Ocean climate is important when predicting future climate scenarios. Siliceous radiolarian tests preserved in seafloor sediment can be used as proxies to investigate and reconstruct the timing of glacial/interglacial cycles and to estimate past sea-surface temperature. Sediment samples were taken from two 2.5 m sediment cores recovered from the continental slope of the Sabrina Coast region, East Antarctica, during RV Investigator voyage IN2017-V01. The aims of this study were to determine if the radiolarian microfossil record is useful as a proxy to reconstruct palaeoclimatic parameters in this region and, if so, to estimate summer sea-surface palaeotemperatures. This research demonstrates the timing of glacial/interglacial cycles can be identified in Sabrina Coast sediment using radiolarian abundance and assemblage data. The Holocene and previous glacial period (i.e. marine isotope stages 1 and 2) are clearly differentiated with Holocene oceanographic conditions being conducive to biosiliceous sedimentation, whilst conditions during the preceding glacial period are not. Holocene summer sea-surface palaeotemperature estimates generated using the Imbrie-Kipp transfer function ranged between -3.26°C and 3.26°C. Future research will use the radiolarian record from longer (~14m) Sabrina Coast cores for palaeoclimate reconstruction over multiple glacial/interglacial cycles.

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