Cindy Lou Skipper / Earth & Environmental Sciences / Faculty Mentor: Nathan Brown
North American glaciers and ice sheets have melted as the climate warmed since the Last Glacial Maximum, exposing boulders that were once frozen inside the ice. When these boulders are exposed to sunlight, their surface begins to lose its luminescence signal. With time this signal empties to greater depths. Using luminescence rock surface dating we find the date the glacier melted at the boulder location. To estimate how long the boulders have been exposed to sunlight, several important assumptions are involved, which previous research has ignored. In this study, we use MATLAB to simulate fluctuating levels of snow cover through time to reveal the effects on apparent exposure age. After determining whether varying the number of sunny months per year produces measurably different luminescence depth profiles, we test whether this effect changes with exposure duration. Then, we simulate different hypothetical snow cover histories to quantify the potential bias in apparent exposure age. Using these results, we can more accurately estimate when glaciers retreated from specific regions to better reconstruct past responses of glaciers to climate change, helping us to better constrain future melting scenarios of land ice in response to changing climate.
Leave a Reply