The Cryosphere Discussions www.the-cryosphere-discuss.net 1994-0432 1994-0440 3 1 2009 10.5194/tcd-3-307-2009 http://www.the-cryosphere-discuss.net/3/307/2009/ http://www.the-cryosphere-discuss.net/3/307/2009/tcd-3-307-2009.html http://www.the-cryosphere-discuss.net/3/307/2009/tcd-3-307-2009.pdf 307 321 2009-04-28 Layer disturbances and the radio-echo free zone in ice sheets R. Drews reinhard.drews@awi.de O. Eisen I. Hamann S. Kipfstuhl A. Lambrecht D. Steinhage F. Wilhelms H. Miller Alfred-Wegener-Institut für Polar- und Meeresforschung, Bremerhaven, Germany Institut für Umweltphysik, Heidelberg, Germany now at: Bundesanstalt für Geowissenschaften und Rohstoffe, Hannover, Germany Radio-echo sounding of the Antarctic and Greenlandic ice sheets often reveals a layer in the lowest hundreds of meters above bedrock more or less free of radio echoes, known as the echo-free zone (EFZ). The cause of this feature is unclear, so far lacking direct evidence for its origin. 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