The new advance is in
slot describing the erosional processes involved in cutting the valleys, the speed at which that happened, and the amount of water that could be drained by them.
We're talking discharges of 900 cubic metres per second in the largest channels. To put that in context, English rivers such as the Thames, the Severn and the Trent might only get above 100 cu m/s in flood conditions.
Researchers from the British Antarctic Survey (BAS) worked with a team led from the University of Sheffield to decipher the valleys' development as the northern ice sheet advanced and then retreated, between about 27,000 and 19,000 years ago.
The Sheffield team has spent a decade working out the precise extent of the ice in a remarkable project called Britice-Chrono.
The BAS team was able to use this information, along with the high-resolution seismic imagery, to model how the channels evolved.
