Physics Photo of the Week

Warren Wilson College

Dec. 9, 2005

Ice Sprouts in a Muddy Spring

On November 23, 2005, the day before Thanksgiving, the Asheville, NC area had experienced a hard freeze the previous night.  This is a photograph of a frozen muddy spring on the banks of the conservation pond near the Red Barn on the Warren Wilson College Farm.  The ground was saturated with water both from groundwater (a spring) and from heavy rain the previous day.  Upon freezing during the cold spell, the surface of the soggy ground had capped over with a frozen crust.  As the frozen layer penetrated deeper into thesaturated mud, the expansion of the freezing water built up pressure and eventually broke through the icy crust only to freeze upon emerging.  Notice the muddy tops of each of the ice pillars.  The pen knife is positioned to scale the features in the photograph.  Also notice the curved  needle-like appearance of the ice.  Supposedly the shapes occur when the ice both freezes and protrudes from the frozen ground surface.  This freezing and expansion is responsible for potholes forming in roads during long winter months in cold climates.

The photo below shows the whole spring near the pond that formed this icy patch.  The whole area is about 1.5 to 2.0 meters across.  These formations happen quite frequently in muddy areas during freezing conditions, especially in construction areas where lots of mud and loose dirt are exposed and saturated with water during a rain and freezing event.  The icy areas show as the ice-colored patches in the center of the photograph.

I do not know the common name for this ice formation even though it is quite common and would appreciate any further information from readers.  I also do not know how fast these formations grow during freezing conditions.  Do they grow at the rate of several cm/min or cm/hour?  It would be a real challenge to capture these ice columns growing with a time sequence and digital cameras.  I invite interested photographers to brave the cold nights during rather unpleasant conditions to photograph these crystals growing out of the ground!

Photos and Text by Donald F. Collins