Pleistocene tunnel valleys in northern Germany – Influence of the underlying geology on tunnel-valley formation and reactivation
Left: Overview map, showing the distribution of the subglacial tunnel valleys in northern Germany. Today, most tunnel valleys are completely infilled by sediment and no longer visible at the surface. Right: Simplified map of the maximum tunnel-valley depths. Tunnel-valley courses are restricted to their thalwegs clustered into five depth zones based on their maximum depths of erosion. The depth zones can aid to estimate potential future depths of erosion
Source: BGR