Saturday
Mar162013

Accidents on Lake Memphremagog and Seymour Lake

In early March Jacques LeBlanc was removing fishing shanties from friends and himself from Lake Memphremagog.  It appears he lost his established route when pulling his own shanty at the end of the day.  He broke through on a hard to see, folded pressure ridge. Click here for more

In Early February, two fishermen in a truck broke through on Seymoure Lake.  Click here for more

Wednesday
Feb272013

Turning the Bend

Cutting a large hole in Shelburne Bay to experience falling in and getting back on the ice. March 9, 2010.

 As February finishes, the days are getting longer quickly and the sun is getting higher in the sky.  This increases average air temperatures and inhibits the thickening of ice sheets.  The end of season thaw takes place in two to four weeks rather than the 2-3 months it took to get to maximum thickness.

The obvious explanation is the greater strength of the sun.   Late December days in Burlington (44.5 deg N Latitude) are 8 hours long.  The will be 12 hours by mid-March.  The sun angle has a bigger effect: there is about twice as much energy delivered to horizontal surfaces in March as December (not including the considerable effect of more clouds in December). The combined effect of angle and duration of sunlight is that about three times more energy is available on a sunny March day than in December.

Getting a feel for the bearing strength limits of 5" thick, well thawed small grained (S2) ice. A dry suit can be a wonderful thing. March 12, 2012 Photo:. Al Russell

Traditionally, early March has been a great time to get in a little end of season ice time:  warm days and a foot or more of ice in most of the bays on Lake Champlain.   For two of the last three years, we have had the season end in early March.  This year  is coming into March with ice about half as thick as usual so we expect it to go fast when the weather turns a little warmer and sunnier. 

Click here for the recently updated End of Season page.  It gives an overview of considerations for late season ice.

Bob

Tuesday
Feb192013

Double Ended Folded Ridges

The southern end of the double ended folded ridge in mid February.

Most pressure ridges are connected to other ridges or shore but occasionally one will form that is isolated in the middle of an ice sheet with no connections. It also grew to 50+ foot width and it thinned the ice for 350 feet from its edge.  Usually folded ridges freeze up or turn into overlapped ridges.  One formed early in the 2012 season on Shelburne Pond (VT) and persisted for the entire ice season.  Click here for a report on what we observed and what we think is going on. 

Monday
Jan282013

The largest calving event ever recorded on video 

Ilulissat Glacier in Western Greenland

 

Run this link for the calving event

Run this link for the whole Chasing Ice movie.

Friday
Jan252013

Lots of New Ice

Sebago Lake, Maine. Photo by Lee Spiller

Like much of the ice belt, Northern New England is finishing a week of very cold weather (cold by recent standards anyway). We suddenly have black ice all over the place. The new ice has gotten thick enough (4-6") for pressure ridges to form.  I happened to be near where one formed yesterday and I happened to have a running video camera in my hands (to record the sound) and it happened to be pointed pointed in the right direction...more luck than sense.  Click Here for more infomation and a link to the video

Bob