Document Type
Thesis
Abstract
The Arctic is experiencing climate change induced warming at a rate 3 to 4 times faster than the rest of the globe due to a phenomenon known as Arctic amplification. To better understand the current effects of climate change and the paleoclimate of the Arctic, we turned to a proglacial lake in Northern Greenland. Peary Land, a polar desert, is the northernmost region in Greenland and is characterized by a barren landscape. Our study site, Lake Southwest (LSW), is surrounded by small, cold-based glaciers which drain directly into the lake. LSW is a small proglacial lake and provides us with a high-resolution sediment archive that is strongly impacted by glacier dynamics. Lake sediments here capture minute climatic fluctuations over the last ~3,500 years (basal age = 1700 BCE) as retreat and growth of the glacier(s) directly provides sediment into the LSW basin via bedrock erosion. Grain size analysis, 210Pb & 137Cs isotope analysis, and x-ray fluorescence scanning were completed on the 1.5-meter-long core recovered from LSW in 2021. We found that meltwater from the nearby ice caps/glaciers to be the largest contributing factor of non-organic material into LSW. The length of ice-free vs. ice-covered conditions limited the amount and size of sediment which could have been transported into the lake, with said conditions a reflection of a rapidly changing environment. We saw coarser-grained sediments only starting to appear in greater relative abundance over the last 100 years. Changes in the isotope data (specifically Ti and Ca) throughout the core appear to take longer to respond to these fluctuating conditions, whereas grain size changes relatively fast. Further research into a potential relationship between diatom abundance and grain size changes over the last centennial is required to determine if this is an isolated event within the LSW catchment area or applicable to the entire region of Northeast Greenland.
Date Awarded
Spring 2023
Department
Geology
Advisor 1
Nicholas L. Balascio
Recommended Citation
Schmidt, Lauren, "Reconstructing Ice Cap Changes in Northern Greenland Using Proglacial Lake Sediments" (2023). Geology Senior Theses. William & Mary. Paper 45.
https://scholarworks.wm.edu/geologyseniors/45
