Scribe: Josh

The most beneficial discussion topic was likely as follows:
"If pressures are highest in the subglacial drainage system during winter when sliding is usually minimum, why do people say that high pressure means sliding?"

We suggested that it is the *transition* between the distributed "slow" drainage system to the "fast" tunnel system that accompanies the observed speed-up events (note slow and fast refer to water speed). Bernard brought up Iken's 1980s observations and modeling that suggested that in early summer, water overwhelms the winter/slow subglacial cavity system and jacks the ice up. The distributed system then evolves into a efficient tunnel system, and sliding is inhibited. Hence in early summer we expect high speeds, but in late summer, after the tunnel system is well developed, we expect relatively slow speeds. See Kamb JGR 1987 paper (in Files of Groups).