Yvonne Smith wins AGU outstanding poster award
January 11, 2016Congratulations to 2nd year DTP student Yvonne Smith who has won an outstanding student poster award for her work on modelling Pliocene iceberg trajectories at the recent AGU Fall meeting. A copy of Yvonne's poster can be found here, and a short description of her work is given below.
The Greenland Ice Sheet (GRIS) contains approximately 7.36m of sea level equivalent that could melt over the next 1000 years. Therefore understanding the response of the GRIS during past warm periods is fundamentally important. The Late Pliocene (LP) has similarities to the projected 21st Century climate, and there is enough available data to constrain ice sheet and iceberg modelling studies, thus it makes the LP a useful palaeoclimate modelling target.
Within the LP, the mid Piacenzian Warm Period (mPWP) is particularly well documented. Temperatures were 2–3°C warmer than present and CO2 level was about 405ppmv. Multi-climate and multi-ice sheet modelling studies show retreat in the GRIS to higher elevation. However, immediately prior to the mPWP, Marine Isotope Stage M2 (3.3Ma) is a cold period in the warmer LP background. Localized evidence of ice during the M2 exists but if a larger northern hemisphere (NH) glaciation occurred, evidence has been erased. Evidence shows a drop in sea level up to 60m and CO2 at 220ppmv. Climate models show a medium/large NH ice cover is plausible at the M2. The exact extent during both warm and cold periods in the LP remains unclear.
Evidence of this extent can be seen in marine sediment cores as ice rafted debris (IRD) which helps decipher the state of the ice sheet. The distribution of mPWP North Atlantic IRD in space and time tells us about the location of iceberg-producing glaciers of the NH. Using the M2 and mPWP climate scenarios, iceberg trajectories were modelled to see where IRD would be found in the North Atlantic under warm and cold LP conditions. The poster I presented at AGU compared the modelled trajectories to the evidence of IRD adding further weight to a NH glaciation.