Friday, February 7, 2014

Walk on Water

Have you ever watched a water strider insect skate on the lake or slow moving river?  It's a fun summer activity to observe their movements and dance on water.  How is this possible?  Why don't they sink?  It's because of the attraction of water to each other.  (Note - Valentine's Day is a week away - maybe you can celebrate the day with a clean, cool glass of water with your valentine.) Individual molecules of water form hydrogen bonds between each other which results in water 'sticking' together.  Water is cohesive and adhesive as these bonds keep the molecules together.   Surface tension is present on the surface of water and lightweight critters can then walk on water.  In fact, you can even float a paper clip on water.  Give it a try.  If you put the paperclip in with a couple fingers the paper clip will sink. Instead, use another paper clip as a little scoop to lower the paper clip on to the surface of water.  This keeps the oils in your fingers from interfering with the surface tension.  The paper clip will then be held up by the water even though it is slightly more dense. 
 

Humans can't quite walk on water - except this time of year.  The chilly days of winter have been going on for months now.  Ice fisherman are out in the bay, skaters are out, but there also can be hikes on water.  The sea caves on the south shore of Lake Superior are open displaying the interesting patterns of frozen water.   The area in the summer is only visible by boat but in the frozen winter more people can enjoy the beauty and walk right in the cave-like openings. The right conditions to walk out to the caves don't occur every year or throughout a whole winter season.

An automated Apostle Islands Ice Line is available - call (715)779-3398, extension 3, for current ice conditions at the mainland caves.
More information on the science of the ice formations and more photos are at
http://www.nps.gov/apis/naturescience/caves.htm

Another opportunity to walk on water (ice) is through the St. Louis River Alliance.  On Saturday, Feb 15 at 1 p.m. the organization is having an outing to explore old saw mill sites that were present on the St. Louis River.  For more information, go to www.stlouisriver.org.

Enjoy water outdoors all the year through.  Be sure to stay safe and travel with caution on ice as the season comes to an end.  Spring will come some day.

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