inside that is between a couple and a couple of dozen meters thick depending on side temperatures nowadays it s possible to measure it precisely the rock is illuminated with countless electrical sensors increasingly less rock inside the mountain is permanently frozen even here at germany s highest peak the permafrost is visibly thawing. cynicism side. we ve been observing a clear reduction in the permafrost since february of 2007 so more than a decade ago the occasional cold winter can slow the process slightly but over the years we ve seen the thaw advance rubble and rock stabilize the ice in the critical areas where. the thought has set in but we have to keep a careful eye on it in case instabilities arise. alpine instability