Heading for Record-Breaking Low Water?
The water level in Lake Superior by mid-October was just 1
inch from the lowest recorded mean for that month. The lake’s mean
level was at 600.9 feet and the record was 600.7 feet in 1925. The
level is essentially measured as feet above sea level and does not
indicate the depth of water.
Dry, warm conditions during the summer and much of fall might
be blamed for Lake Superior again heading toward its lowest water
levels.
Traditionally, water levels decline in fall and winter,
according to U.S. Corps of Engineers hydrologist Tim Calappi. “(This
year) the seasonal decline started about a month early, in the end of
August time frame.”
A mild winter and unfrozen water increases evaporation.
Lake-effect snow, drawn from the lake, doesn’t add water into the
system, but at least it keeps water in the basin.
“It would be nice to get large snow-producing systems from
outside the basin,” Tim says, but “I’d rather see a bunch of
lake-effect snow on the ground in February than no snow.”
Lake Notes
 On
the National Oceanographic and Atmospheric Administration map showing
its prediction for winter - www.noaanews.noaa.gov/stories2006/
s2716.htm - you can’t miss the darker red circle centered in Minnesota
and encompassing most of Lake Superior. This means warmer than usual
temperatures. The prediction also is for normal precipitation. For Lake
Superior, warm is not necessarily better. Good ice covering reduces
water evaporation.
About 73 species of fish live in Lake Superior, says the U.S. Geological Survey, which conducts fish inventories.
|
