DRANGAJOKULL SURGES DURING THE LAST 300 YEARS, UNIQUE SURGE CHARACTERISTICS IN TERMS OF ICELANDIC SURGE-TYPE GLACIERS

We have reconstructed the surge history of Drangajökull ice cap, based on geomorphological mapping, sedimentological studies and review of historical records. Over the last 300 years, each of the three surge-type outlet glaciers of the Drangajökull ice cap in northwest Iceland has surged 5-7 times with surge interval which varies from 10-140 years within and between outlets. The geomorphological mapping reveals twice as many surges as previously observed and characteristic landforms and sediments in the forefields of the Drangajökull surge-type outlets. In contrast to most other surge-type outlets from Icelandic ice caps, the Drangajökull outlets are confined within valleys which affect the forefield geomorphology, which is characterised by glaciofluvial landforms, moraines and a thin sheet of till with numerous boulders.

Digital Elevation Models (DEMs) were used to quantify the maximum surge events during the 18^th and 19^th century. Furthermore, the DEMs were used to analyse surface elevation and volume changes during the most recent surges. The DEM analysis have revealed characteristics of Drangajökull surges that are much more similar to Svalbard surges rather than surges from the bigger ice caps in Iceland, such as long surge duration, surface expression, longer initiation and termination phases.