THE INITIATION AND DEVELOPMENT OF A JÖKULHLAUP FROM THE SUBGLACIAL LAKE BENEATH THE WESTERN SKAFTÁ CAULDRON IN THE VATNAJÖKULL ICE CAP, ICELAND

• Main Authors: Bergur Einarsson, Thorsteinn Thorsteinsson, Tómas Jóhannesson, Icelandic Meteorological Office
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Vatnajökull; The Cauldron; Skaftá; glacier; Ice cap; Ice Shelf; Iceland
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.580.9699; http://www.vedur.is/media/vedurstofan/utgafa/greinargerdir/2009/Einarsson_The_initiation_and_development_of_a_jokulhlaup.pdf

Results from investigations of a jökulhlaup from the subglacial lake beneath the Western Skaftá cauldron in the Vatnajökull ice cap are reported. Following thermal drilling into the lake in June 2006, the lake temperature was measured and the elevation of the ice shelf covering the lake recorded with a permanent GPS station. A number of parameters were monitored in the Skaftá river where jökulhlaups from the cauldron regularly emerge. Subsidence of the ice shelf was recorded by the GPS instruments during a jökulhlaup from the Western cauldron in September 2006. We estimate that 64 Gl of water emptied from the cauldron during this jökulhlaup, which reached a maximum discharge of 150 m3/s. The maximum discharge at the glacier snout was 135 m3/s and the speed of the flood front under the ice cap was found to be in the range 0.2−0.4 m/s.