Print Email Facebook Twitter Stability of the floating ice shelf of the Petermann glacier and its response to a changing environment Title Stability of the floating ice shelf of the Petermann glacier and its response to a changing environment Author Rosier, Job (TU Delft Civil Engineering and Geosciences) Contributor Lhermitte, Stef (mentor) Mottram, Ruth (graduation committee) Degree granting institution Delft University of Technology Date 2019-08-19 Abstract Nearly all major glaciers in Greenland have reduced in size over the last two decades. An increase in the amount of ice transported from the Greenland ice sheet to the oceans is predicted following an increase in Arctic air and ocean temperatures. One of the last glaciers with a floating ice shelf and draining a substantial area of the Greenland ice sheet is the Petermann glacier in North West Greenland. With two major calving events in 2010 and 2012 the extent of its floating ice shelf was reduced to only half of that prior to 2010 and since 2016 new fractures indicate a new calving event is predicted to reduce the length of the glacier by ~14 km. Multiple studies have indicated that after the major calving event of 2012 the glacier accelerated and a new increase in the velocity, possibly linked to the next calving event, has already been observed. With every part of the glacier’s ice shelf that is lost the resistive force that holds the glacier back is reduced and the amount of ice drained to the ocean increases. Losing its entire ice shelf could lead to a significant increase in the contribution of the Petermann glacier to global sea level rise as the Petermann fjord extends inlands below sea level for nearly a hundred kilometers. This study uses ice thickness and surface elevation data combined with velocity data from different sources to analyze the current and future stability of the Petermann glacier. Ice thickness and the velocity data is used as input in a fracture model in order to investigate the different contributions of stress, thinning and an increase in the availability of surface water to the depth crevasses can reach. The areas on the glacier that show locations where crevasses penetrate deep into the ice indicate that the glacier is vulnerable to fracturing in those spots. Connected weak spots might indicate further potential for future calving events. The results derived from the thickness data and the subsequent melt rates show that near the grounding line the glacier is experiencing significantly larger melt rates than near the calving front. The high melt rates are concentrated in space and caused three large basal channels to form, which run downstream parallel to the flow direction. The location of the western channel corresponds to the location of fractures that initiated during the same time the channel deepened, indicating a relationship between an increase in melt rate and fracturing. This relation is also observed in the results from the fracture model, where there is enough water and the ice shelf thinness fractures are capable of penetrating deep in the glacier ice. The results also show that when the average melt rate between 2011 and 2017 continues to prevail the floating ice shelf of the Petermann might be gone within the next decade Subject glacierClimate changeRemote Sensing To reference this document use: http://resolver.tudelft.nl/uuid:33bc746a-472d-4919-af26-e12896bf9abb Embargo date 2020-08-19 Part of collection Student theses Document type master thesis Rights © 2019 Job Rosier Files PDF Thesis_report_Job_Rosier.pdf 16.13 MB Close viewer /islandora/object/uuid:33bc746a-472d-4919-af26-e12896bf9abb/datastream/OBJ/view