Háskóli Íslands

Ph.D. student: Joaquín M.C. Belart
 
Dissertation title: Mass balance of Icelandic glaciers in variable climate
 
Opponents: 
Dr. Francisco Navarro, Professor at the Universidad Politécnica de Madrid, Spain.
Dr. Beata Csatho, Professor at the University at Buffalo, NY, USA.
 
Advisors: Dr. Eyjólfur Magnússon, Research Scholar at the Institute of Earth Sciences and Dr. Etienne Berthier, Professor at Laboratoire d’Etudes en Géophysique et Océanographie Spatiales, Université de Toulouse, France.
 
Doctoral committee: 
Finnur Pálsson, Engineer, Institute of Earth Sciences, University of Iceland.
Dr. Guðfinna Aðalgeirsdóttir, Professor at the Faculty of Earth Sciences, University of Iceland.
Dr. Simon Gascoin, Research Scientist at CNRS, France.
 
Chair of Ceremony: Dr. Andri Stefánsson, Professor and Vice-Head of the Faculty of Earth Sciences, University of Iceland.
 
Abstract:
This thesis focuses on remote sensing techniques to accurately measure geodetic mass balance of Icelandic glaciers from seasonal to decadal time spans and the relationship of mass balance to climate.
 
As an example of seasonal mass balance, the winter mass balance of Drangajökull was measured from satellite sub-meter stereo images at the beginning, middle and end of the 2014–2015 winter using data from the Pléiades and WorldView-2 satellites. The results were complemented with in situ snow density measurements and validated with snow thickness measurements. The study concludes that images from the sensors mentioned above may often be used to monitor seasonal mass balance without tedious field logistics.
 
A vast archive of aerial photographs exists for Iceland extending back to 1945. Since then, most glaciers were surveyed every 5 to 20 years. In addition, a wealth of modern satellite stereo images is available since the early 2000s. This creates a unique dataset to construct a 70-year time series of geodetic mass balances. Eyjafjallajökull was used to develop semi-automated processing chains based on open-source software. The result is a detailed record of glacier changes resulting from climatic and volcanic forcing. Simple linear regression of the annual mass balance of Eyjafjallajökull indicates that most mass balance variations can be related to changes in summer temperature and winter precipitation. It also allows to infer the sensitivities of mass balance to these two climatic variables.
 
The processing chain was then applied to 14 Icelandic glaciers and ice caps spatially distributed in all quarters of Iceland. The mean and standard deviation (±SD) of mass balances of the target glaciers were –0.44±0.16 m w.e. a–1 in 1945–1960, 0.00±0.21 m w.e. a–1 in 1960–1980, 0.11±0.25 m w.e. a–1 in 1980–1994, –1.01±0.50 m w.e. a–1 in 1994–2004, –1.27±0.56 m w.e. a–1 in 2004–2010 and –0.14±0.51 m w.e. a–1 in 2010–2015. The glaciers located at the south and west coasts revealed the highest decadal variability. This study improves the knowledge of the Icelandic glaciers prior to the 1990‘s and how subsequent warming altered their mass balance.
 
About the doctoral candidate:
 
Joaquín M.C. Belart was born in 1989 and grew up in Jaén, Spain. He studied Land Surveying in 2007–2011 and Cartographic and Geodetic Engineering in 2011–2013, obtaining both degrees at the University of Jaén. Joaquín then worked at the Institute of Earth Sciences, University of Iceland, as a research assistant before starting his doctoral studies in 2015 as a joint degree between the University of Iceland and the University of Toulouse III – Paul Sabatier.
 
The Ph.D. Candidate is enrolled in a joint degree between the University of Iceland and the University of Toulouse III – Paul Sabatier.
The project was funded by the University of Iceland Research Fund, and mobility between the two universities was funded by the Jules Verne Research Fund.
 
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