Variations of southeast Vatnajökull, past, present and future

• Main Author: Hrafnhildur Hannesdóttir 1977-
• Other Authors: Háskóli Íslands
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2014
• Subjects: Doktorsritgerðir; Ela; Vatnajökull; glacier; Iceland
• Online Access: http://hdl.handle.net/1946/20048

The temperate outlet glaciers of SE-Vatnajökull are sensitive to climate change, and provide important climatic and glaciologic information through their recorded variations in mass balance and extent. They descend to the coast from an elevation of 1500–2100 m a.s.l., are located in one of the warmest and wettest area in Iceland and have among the highest mass turnover rates worldwide. The area was settled in the 9th century, and people have lived in close proximity to the glaciers, which has led to numerous contemporary written documents, also provided by the travelers and explorers of the 18th and 19th centuries. According to the unique local historical records, the outlet glaciers advanced in the latter half of the 17th century and extended far out on the lowlands in the mid-18th century. The glaciers were at their LIA terminal moraines around 1880–1890 and soon thereafter started retreating. The well-preserved glacial geomorphological features (including lateral moraines, trimlines and erratics) outlining the LIA maximum extent of the glaciers, have been mapped in this study. A reconstruction of the LIA glacier surface geometry was made, based on the geomorphological data, historical photographs, and information from the oldest reliable topographic maps of 1904. A LiDAR (laser scanning) digital elevation model (DEM) from 2010/2011 provided a reference topography for the reconstruction. From the elevation of the uppermost LIA lateral moraines, the equilibrium line altitude (ELA) was estimated to have been ~300 m lower during the LIA than around 2010. Various datasets on glacier extent and geometry since the end of the 19th century have been used to derive area and volume changes for the period 1890–2010. DEMs have been created from maps, aerial images, DGPS measurements and airborne surveys. In the period 1890–2010 the glacierized area shrunk by 164 km2, the outlet glaciers lowered by 150–270 m near the terminus and collectively lost 60±8 km3 of ice, equal to a global mean sea level rise of 0.15±0.02 mm. The ...