I recently spent a few pleasant days in Scotland, and had the opportunity to visit the Carlops Meltwater Channels on the southern flank of the pentland Hills, not far from Edinburgh. Very impressive! In the photo above you can see how the meltwater (probably flowing deep beneath wasting ice) has flowed in many different channels, splitting and bifurcating and leaving isolated "islands" between channels as they have been broadened. Why subglacial meltwater does this is still a bit of a mystery, because one would have thought that a deep channel, once cut, would continue to be the most attractive route for future meltwater flow. Maybe this anastamosing / bifurcating behaviour argues for a strong seasonal rhythm, with meltwater flow ceasing every winter, allowing ice to fill channels and block them, forcing meltwater to find a new route in the next melting season......
The meltwater channels were studied by Brian Sissons and discussed in this paper:
Sissons, J.B. (1963) "The glacial drainage system around Carlops, Peeblesshire".
Transactions of the Institute of British Geographers, 32, pp 95–111.