Ash distribution and cavities in Icelandic glaciers, a marker for snow accumulation and radar signal velocity change

Sammanfattning: Glaciers in the geologically active Iceland has a high scientific as well as touristic value. In this thesis, the two largest glaciers on Iceland have been studied with GPR to find if the method is suitable to use in future glaciolocial studies where accumulation patterns and similar attributes are in focus in a world of deglaciation. The studies at Langjökull were performed over a manmade icetunnel, and the studies at Vatnajökull were done at Háabunga, where a meter-thick ash-layer was deposited in 2011. At Langjökull the results were good enough to say that the method is suitable to find tunnels and crevasses with GPR, and the GPR measurements together with a CMP measurement at Háabunga yielded an accumulation pattern model with correct depths to the ashlayer, depth ranging from 10.2–17.5 m. This makes it an excellent tool for glacier studies.