Inches and miles

In a play on "give 'em an inch and they'll take a mile," this week's media brought news that the level of the Great Salt Lake in Utah is four and a half feet below its historic average. At 4,195.5 feet elevation, the lake covers 1,000 square miles. At its normal level (4,200') the lake is 70% larger, 1,700 square miles. Doing the math, 54" of elevation increases the lake by 700 square miles, so in this case an inch equals about 13 (square) miles. Salt crystals are grown at the point saline water reaches saturation, about 26% salt. A smaller lake, of course, contains the same amount of salt, so with lower lake levels, the salt concentration has increased to the advantage of salt production. But it was only a decade ago that rising levels of the Great Salt Lake threatened rail and highway arteries, flooded saltworks and prompted the state to install two massive pumps to protect against the rising lake levels. Mother Nature has her rhythms.