Interactions between Ice Sheet Dynamics and Glacial Isostatic Adjustment: The development and application of a new method to simulate the Antarctic Ice Sheet over the last glacial cycle

• Main Author: van Calcar, Caroline (author)
• Other Authors: van der Wal, Wouter (mentor), Delft University of Technology (degree granting institution)
• Format: Master Thesis
• Language: English
• Published: 2020
• Subjects: Glacial Isostatic Adjustment; Antarctic Ice Sheet; Ice-sheet-shelf model; Numerical modeling; Antarctic; East Antarctica; The Antarctic; West Antarctica; Antarc*; Antarctica; Ice Sheet; Ice Shelves
• Online Access: http://resolver.tudelft.nl/uuid:8a3a4e21-a6f0-4874-a41f-e26ac95f03be

The Antarctic ice sheet is a complex system highly influenced by global and local processes and characteristics including a varying bedrock elevation and structure of the solid Earth and a changing climate. Sea level rise has a high impact on society and the improvement of forecasts are vital to generate both adaptation and mitigation strategies. A recent comparison of 15 ice sheet models projected that the Antarctic Ice Sheet could contribute -7.8 to 30 centimeters of sea level rise between 2015 and 2100, meaning that sea level rise could increase a lot although the uncertainty is high. To better predict the future of the AIS, more accurate simulations of the evolution of the AIS are needed. The Antarctic ice sheet consist of three main components: grounded slow-moving ice, fast flowing ice streams or outlet glaciers and floating ice shelves. Over glacial-interglacial cycles, the evolution of an ice sheet is influenced by Glacial Isostatic Adjustment (GIA) via two negative feedback loops. First, vertical bedrock deformation due to a changing ice load alters ice-sheet surface elevation. Second, bedrock deformation will change the location of the grounding line of the ice sheet. GIA is mainly determined by the viscosity of the interior of the solid Earth which is radially and laterally varying. Underneath the Antarctic Ice Sheet (AIS), there are relatively low viscosities in West Antarctica and higher viscosities in East Antarctica, which affect the response time of the above-mentioned feedbacks. However, most ice-dynamic models do not consider lateral variations of viscosity in the upper mantle in GIA feedback loops when simulating the evolution of the AIS. The main research question of this study is: •What is the effect of the interaction between Glacial Isostatic Adjustment and ice sheet dynamics on the Antarctic Ice Sheet growth during the last glacial cycle? This study presents a new method to investigate 3D GIA feedback effects in detail at any chosen period during the last glacial cycle. The method is ...