Swamp Ice


A person on foot walked along the edge of the cattail swamp on Shelburne Pond (VT) for about 100 feet before he found a thin spot. Frozen swamps are can be a facisinating place to skate or walk.  Just keep in mind that swamp ice is likely to be dodgy ice.  Click here for an article on the subject.


Ice From Space


Lake Champlain Feb 23, 2011. Thin ice formed on the dark expanse of the lake two days before this. For the past few years the National Weather Service in Burlington (VT) has been posting  pictures of Lake Champlain from the Terra or Aqua satellite.  It is a handy way to get a large scale view of what is happening with ice in your region or anywhere in the country or southern Canada.  Obviously, at this resolution you can't tell much about the thickness, quality or degree of thaw of the ice.  Click here for an article on how to access the images for all of the US and the basics of  navigating around the University of Wisconsin Modis Today website. 


Black Ice

A good friend on Canyon Ferry Reservoir Montana. Photo by Kristina PritchardAfter Winter's late start and several snowstorms there is presently good skating and sailing ice in many places.  Canyon Ferry near Helena MT has some particularly expansive, snow free ice.  Central New Hampshire has had specular sailing and skating ice for a week or so. Yesterday's satellite picture shows some bare ice in northern Michigan and Wisconsin as well. New ice offers opportunity for fun and for falling through. Please be prepared for both. 



Tragedy in Rangeley


On night December 30th five snowmobile riders left a resturant in Rangeley Maine and went onto the ice on Rangeley Lake.  All are believed to have driven their machines into a mile diameter area of open water on the lake. One survived and one has been recovered.  The other three are missing.


A sketch of the open water based on a Maine Warden Service aerial photograph taken 1/3/13.

The open water as seen on Jan 1, 2013 late in the day, from Route 4 about 3/4 mile south of Rangeley. It is speculated that the riders were headed for the connector trail that starts at the blue marker on the map above. The additional information that was part of this blog posting has been moved to the Tragedy in Rangeley page.  This page has been updated on May 3, 2013 and again on May 8, 2013


Layered Ice

Less than a day after the snow stopped the slush layer has reached the surface in many places on this pond. The black ice layer was between a skim and about an inch when the snow fell.

The first big snowstorm to hit the Northeast left 13 inches of snow in the Champlain Valley and similar amounts over many areas in the ice belt.  We had a fair amount of thin ice before the snow fell.  13 inches of snow is enough to submerge up to a foot of ice.  All the ice that is in place now is likely to get a slush layer on top of the black ice which will take a while to freeze fully, depending on several factors:

  1. How much insulating snow is over the slush layer
  2. Temperatures over the next couple weeks
  3. How much new snow falls. 

When the slush does fully freeze it tends to do in an irregular fashion with areas that are better insulated taking longer.  It is also likely that there will be some thinning of the black ice layer as there is no heat being pulled out of the top of the black ice layer and the water under the ice is usually two or more degrees warmer than freezing just a few inches from the bottom of the ice.

The Lake Dunore tragedy three years ago was the same situation.  The main snowfall was 8 days before the accident.  Even 12 days after the snowfall there were still places where the slush had not fully frozen.  The thickness of black ice layer was also quite variable (probably from melting from the bottom). The ice on Waterbury Reservoir in mid-January 2012 was also layered ice. 

The situation this year is especially concerning because the black ice layer is so thin on many lakes and ponds making it a hazard for dogs who may see nothing but a flat snow field rather than a pond.  Obviously, if it is not strong enough for dogs it is not strong enough for people. 

If you go out, be fully equipped: test pole/spud/drill, ice claws, life jacket, buddies with throw ropes.  Really check the ice carefully and pay especial attention to the thickness of the black ice layer.  The frozen slush layer on top is likely to be too irregular to count on so everything depends on the black ice layer.