Paleo-VITALS team overview

Transcription

1 Paleo-VITALS team overview The team : Anne de Vernal & Claude Hillaire-Marcel, Geotop UQAM Evan Edinger, MUN; Markus Kienast, Dalhousie; Roger François, UBC + Collaborators : Martin Frank, Simone Kasemann, Matthias Moros, Ralph Schneider, Owen Sherwood, etc. + PDFs : Pasha Karami, Jenny Maccali, Lucie Ménabréaz + Graduate students : Estelle Allan, Aurélie Aubry, Aurélien Blenet*, Sam Davin, Alexandra Filippova, Sarah Fines-Neuschild, Marie-Camille Gasparotto, Olivia Gibb*, Nicole Marshall, Marie-Michèle Ouellet-Bernier*, Barbara Neves, Genna Patton * Thesis completed

2 The key hypothesis The convection in the Labrador Sea will not survive climate warming unless there is a significant reduction of freshwater export through the Canadian Archipelago and Baffin Bay What was the natural variability of hydrographical conditions in the LS, especially during warm interval of the past? What is the relationship between freshwater/meltwater fluxes from the Arctic and Greenland on LSW formation? What about LS ventilation (and effect on deep water properties) from extreme cold to extreme warm climate?

3 Keratoisis The means to tackle the questions Corals Desmophyllum danthus Sediment cores Biomarkers e.g., UK37, IP25, PIP25 Advantage : annual resolution, Organic + CaCO 3 carriers of geochemical/isotopic signal Advantages : mud everywhere, Many biogenic remains (biomarkers, assemblages )+ CaCO 3 carriers of geochemical/isotopic signal

4 A few highlights Corals Desmophyllum danthus Jenny Maccali - Boron isotopes as tracers of paleo-ph Lucie Ménabréaz - Neodymium isotopes in deep scleractinians vs ambient water properties and origin (NADW vs. LC) Evan Edinger 14 C activity in calcite and gorgonin of gorgonian corals as tracer of recent ventilation rates Keratoisis

5 A few highlights Corals Gorgonian corals : Protein (org C) + Calcite (inorg C) 14 C in gorgonin layers reflect 14 C from surface productivity (food source), whereas in the CaCO 3 14 C reflects ambient DIC pool (i.e. a delayed bomb- 14 C signal related to ventilations rates Evan Edinger 14 C activity in calcite and gorgonin of gorgonian corals as tracer of recent ventilation rates Keratoisis

6 Edinger et al. CANQUA 2015

7 A few highlights Genna Patton - Neodymium isotopes in foraminifers as tracers of ocean circulation : core top calibration A Filippova, M Kienast, M Frank, R. Schneider Core top calibration of alkenone as paleothermometer Sediment cores Biomarkers e.g., UK37, IP25, PIP25

8 Filippova et al. G-Cube, in review Compilation of published (n=94) and new (n=99) surface sediment data from the western North Atlantic Samples from sea ice exhibit a significant warm bias. Deviation from the linear regression relates to advection of allochthonous material and stratification. Despite the uncertainties, alkenone unsaturation allows reconstruction of climatologically consistent SST records from many regions of the North Atlantic.

9 A few highlights Genna Patton - Neodymium isotopes in foraminifers as tracers of ocean circulation : core top calibration A Filippova, M Kienast, M Frank, R. Schneider Core top calibration of alkenone as paleothermometer Estelle Allen palynology from Disko Bugt reflecting changes in the relative strength of the northward Atlantic water flow Sediment cores Biomarkers e.g., UK37, IP25, PIP25 Gibb et al. - Sea surface conditions in the Labrador Sea and Baffin Bay since the last deglaciation

10 Gibb et al. The Holocene 2015 Trend of increasing salinity with decrease summer insolation from early to late Holocene Millennial oscillations in the relative contribution of the NA and BB currents Large amplitude natural variability

11 What is next Filling the hiatus between instrumental, historical and paleo-data Marie-Camille Gasporotto Decadal-centennial variations in the climate and hydrography of the Labrador Sea over the last 2 ka (a contribution to PAGES-2K)

12 Summer 2015 expeditions on the R/V Maria S. Merian Mud samples (MUC, Gravity, Box MSM44/Dorschel & Hebbeln, AWI & Bremen MSM45/Schneider, Kiel MSM46/Moros, IOW Nicole Marshall - Sampling from MSM 46 relevant for paleo- VITALS

13 What is next Filling the hiatus between instrumental, historical and paleo-data Marie-Camille Gasporotto Decadal-centennial variations in the climate and hydrography of the Labrador Sea over the last 2 ka (a contribution to PAGES-2K) Exhautive analytical program to come for dating and making reconstructions based on the different tracers from sediment and corals Documenting LS ventilation (and effect on deep water properties) from sedimentary and coral data (Jenny, Nicole) Exploring the Labrador Sea paleoclimate and paleoceanography during extreme warm episodes of the past, including the Pliocene Aurelie Aubry From the warm Pliocene to the cold Pleistocene using Ocean Drilling Program (ODP) cores Data acquisition and compilation + collaboration within the framework of modelling endeavors