Ponds in Winter

Tim Matson is a pond architect who has an extensive website about making, maintaining, and upgrading ponds.  The January 2017 Pondology article is about ice on ponds.  


First Ice on Lincoln Pond 

The following is a trip report from your first time on the ice.  It is presented with pictures and commentary about ice features that are good to know about.  While it will focus on potential hazards it will also talk about interesting ice features that do not have much to do with staying dry.  The comments feature is open if you have  something to say or questions.  

All picture captions are under the pictures they refer to.



Lincoln Pond and a few nearby ponds are often where we find our first ice.  The following are pictures and commentary about the ice we found and lessons learned and relearned. 

A prolonged moderate cold snap finally put some ice on Lincoln Pond in the eastern foothills of the Adirondack Mountains.  Seven of us spent the day checking the ice out and reawakening our skating mussels. 

The lower (northern) secion of the pond is shown above.  Its long axis is about 1.5 miles.  We skated around the pond several times, accumulating 17 miles over about 4 hours.


There were three distinct generations of ice.  The oldest was grey ice with a thin snow ice surface over black ice.  The thickness was over two inches as it took several hard pokes with a test pole to go through the ice. 

As you can see, we tend to get a bit spread out.  In fact we get tend to be much more spread out than this picture shows.  That increases the chance of someone finding ice that is too thin.  In Sweden, club trips are more formal about staying relatively close with a skilled point person out in front and everyone else behind them. People in the pack are often skilled enough to call out if think there is something about the ice to be concerned about.    Rescuing someone and getting them changed into their dry clothes goes more quickly with more people.

Another thing to be wary of is the tendency to relax as the day progresses. On ice that is a mixture of black ice that is thick enough (2") and ice that is not thick enough, you need to pay attention.  Staying dry is more likely if everyone is vigilant about poking the ice, especially at ice edges or other features that might be problematic.   

The next youngest ice was a smooth black ice that was about two inches based on being able to poke a hole though the thickness about half the time with a single hard poke. It had smeared out frozen slush areas that can be seen in the above picture.


The newest ice was easily poked through and was 35 mm to 37 mm (1.5") in the few places it was measured.(Click here for more information on the role of thickness on the strength of thin ice and safety margins of thin ice.)  It was noisy when skated on it. Much but not all of this ice had a rougher surface from the large dendritic primary ice crystals . The next picture shows this better.  The new ice hole shows a classic white splashout rim on the frozen hole. You can see the junction between the grey ice and the newest ice in the upper right of the picture. 


 This in an example of the rougher surface texture in the youngest ice.  This surface texture was not always present on the thinnest ice but it was most of the time. 

A frozen  new ice hole with a pronounced splash out rim.  This appears to be the middle age ice based on its clarity, thickness and smooth surface texture.

 The upper part of the lake has a band of youngest ice in the foreground which does not have a lot of surface texture. It was about 35 to 40 mm thick.  The white/grey band out further is a frozen ice edge.  The ice beyond the edge is less than an inch thick, too thin to thin for any of us to stay on top of.  We skated along the shore on the thicker ice. It was a sporting trip with lots of ice noise and companion cracks leading the way.  After about 1/4 mile the 35-40 mm ice pinched out.  

The inlet from the upper pond to the lower pond.  The flow rate is relatively low.  The melting is caused by the warmer deeper water (probably about 37 degrees) mixes in the culvert and creates a large open area at the inlet to the lower pond. 

 The outlet from the upper pond into the culvert  has ice formed  within a couple feet of the of the culvert suggesting that the water flow is either cold water from less than a foot under the ice or the deeper water has laminar flow to very close to the culvert.  The outlet at the dam on the lower pond also has a small open area at the dam. 


Patterns in gas bubbles.  The picture is about a foot across.  

An ice star 

White Star:  Ice stars that form in a thin snow cover may have open toped channels. This one was filled with snow.

  For the most part, ice stars do not present any hazards to people on the ice.

Ice stars with rings around them.  The origin is not clear. They may be related to the much larger rings I found a couple years ago. 


Mid October, 2016

The 2017 ice season will be upon us in a couple months.  The NOAA long range forecast suggests that New England is likely to have a typically cold winter with other parts of the ice belt predicted to have a warmer than usual winter.