In reply to Offwidth:
Yeah I know the theory just doesn't seem to happen that way in practice to me.
09/10 it was quite regularly -20 in the highland glens at night and very often -10 or lower and nowhere close to above freezing during the day. Snow laid on the ground from around Pitlochery and north for something like 10 weeks! All the known water ice falls were in great nick
Late November & December 10/11 was also very cold, ice also formed well at all the water ice venues I know of no mater if formed from springs or streams or seepage.
In general water courses don't freeze solid same as lakes sea etc, only so much of the top freezes IMO.
I did Eas Annie during a very sustained cold patch in 09/10 it was -20 on the way over, saw some water dribbling over the ice. Same in Cogne it had been between -10 & -20 for about a week at night and no where close to above freezing at either venue for some time, saw water flowing over the ice at -10 in dribbles at multiple ice falls (but not every one, but probably still flowing behind IMO).
Udlaidh 09/10, 10/11definitely got fatter during the sustained cold patch without needing to thaw too
Can you give me an example of a time when it was too cold over a decent length of time (say at least 2 weeks) for water ice falls to come in to nick (that form from summer streams / springs / seepage) and it definitely just wasn't because they weren't flowing at the time it froze as they were too dry?
I think a lot of the ice on the Ben (and similar) does need freeze thaw but that's because much of the ice forms from snow melt drainage not from frozen water courses.
Post edited at 15:03