MWC erosion

MWC systems

MWC types

Rammer Cleugh - a classic MWC

Cairngorm MWCs

 

 

Recognising meltwater channels

A small channel which forms parts of the Rammer Cleugh system, probably a former sub-marginal chute

In former glaciated areas, meltwater channels and channel systems can be distinguished from normal river channels by criteria which include:

  • an often abrupt end or start in places where normal river channels do not
  • channels may be dry or occupied by only tiny streams and so are misfit
  • channels may locally move uphill, requiring cutting by meltwater flowing under hydrostatic pressure
  • channels cut through local watersheds
  • channels tend not to widen downstream, retaining dimensions of flat floor and steep sides.
  • channel systems that branch and converge but which may cut across the grain of the local terrain as meltwater flow follows the surface slope of the former glacier.
  • For many years meltwater channels in Great Britain were seen largely in terms of water running along the margins of former glaciers. Today most channels are interpreted in terms of sub-glacial and sub-marginal meltwater flow.