The project focuses on the instability of Northern Hemisphere ice-sheets, forcing circulation perturbations in the subpolar North Atlantic and contiguous seas, and offers a unique opportunity to test the real dynamics and consequences of such changes. It involves studying the fossil terrestrial record of ODP Site 984, south of Iceland, spanning the most recent warm period before the present: the Last Interglacial (LIG: Marine Isotope Stage (MIS) 5e, ~129 to 116 ka).
The visit aims to support the continuation of ongoing informal Polish-Indian-Canadian collaboration targeting the high-latitude palaeoceanographic history of the LIG. Of special interest is the climate (in)stability and the timing of inception of full interglacial conditions using marine palynology (dinoflagellate cysts, hereafter ‘dinocysts’ from ODP Site 984, south of Island) tightly integrated with a terrestrial component that occurs in abundance within the samples. We propose an ultra-high-resolution study as supplementary work to data based on dinoflagellate cysts. Spacing between samples is about 200 years on average. Results will be integrated with data from ODP Site 986 (drilled south of Svalbard), which are presently being processed at the BSIP, India (132 additional samples).
Preliminary studies on dinocysts from selected samples indicate a strong correlation between the onset of the North Atlantic Current, as recorded by a sudden increase of the dinocyst Operculodinium centrocarpum, and the methane jump documented from Antarctic ice-cores. Marine and continental records of the warmer-than-present LIG are relatively well documented but their detailed correlation is hindered by the lower resolution of marine data. Study of the terrestrial vegetation record along with the marine dinocysts from the same samples, augmented by palynofacies analysis, will help integrate present knowledge on the Last Interglacial in subpolar regions and separate local from global paleoceanographic trends.