Skaftarjokull Glacier surges, Vatnajokull Ice Cap, Iceland
by Ragnar Sigurdsson (arctic-images.com), Iceland
Some of the Vatnajokull outlet glaciers, while sliding at a normal rate of up to a few metres per day or week (and melting), behave in a peculiar way. Newly formed ice piles up in their upper reaches for a few decades. Then, suddenly, the glacier subsides and a wave travels fast downstream, pushing the lower part of the glacier forward with tremendous force. The ice surface cracks and turns into a jumble of ice towers and crumbling ice cliffs. Water and soft sediments at the glacier base play a part in this phenomenon, termed a glacier surge. Skaftarjokull in the western Vatnajokull ice cap surged in 1995. Millions of cubic metres of ice slid forward at a rate of up to many dozen metres per day and the glacier advanced about 1 km. The photograph shows two persons that were transported by helicopter to a shaky ice tower, knowing that they had very limited time for the visit. Higher resolution images available from firstname.lastname@example.org (there is a licensing fee depending on the use).
Ragnar Sigurdsson (arctic-images.com) (distributed via imaggeo.egu.eu)