Welcome back to the River Ice Photo Blog! It’s been a while since my last post – in between I retired and became a Professor Emeritus and moved 5000 km (~3000 miles) to the east coast of Canada. It’s been a mild winter here – up until now at least – and so I’ve not done much river ice hunting. However, for the first post of 2015 we have some great photos by David M. Brenner – a river ice enthusiast in Ames, Iowa. David calls these “ice teeth”.
Here’s another picture that David describes as the U-shaped terminus of a lead.
David writes, “I associate them with open leads that have no frazil ice. The spacing and regularity can make them look like tractor tracks. The card in one of the images is for scale.”
He also says that, “On our rivers there are often open areas that never freeze. Some of the open areas are where warm urban water comes out of storm sewers. Some are where the fast moving (thalweg) water moves too fast to freeze. The surrounding ice is strong enough to walk on, especially in 2010. The teeth form along open leads during cold snaps, and when new have sharp fresh edges. They are not a melting thing. I do not know what regulates their even spacing but it may have something to do with water speed etc. They need the attention of a Physicist.”
I’ve not seen these before, so if any of you river ice experts out there have an explanation of what might be happening here – please comment below.
If you would like to see some of David’s river ice videos, please check out the following links:
Ice teeth formation on the skunk river:
David’s youtube channel which is all river ice
Thanks David for sharing your photos!