MARQUETTE, Michigan (AP) -- Deep enough to hold the combined water in all the other Great Lakes and with a surface area as large as South Carolina, Lake Superior's size has lent it an aura of invulnerability.
But the mighty Superior is losing water and getting warmer, worrying those who live near its shores, scientists and companies that rely on the lake for business.
Superior's level is at its lowest point in eight decades and will set a record this fall if, as expected, it dips three more inches. Meanwhile, the average water temperature has surged 4.5 degrees since 1979, significantly above the 2.7-degree rise in the region's air temperature during the same period.
A weather buoy on the western side recently recorded an "amazing" 75 degrees, "as warm a surface temperature as we've ever seen in this lake," said Jay Austin, assistant professor at the University of Minnesota at Duluth's Large Lakes Observatory.
Along Superior's shores, boats can't reach many mooring sites and marina operators are begging the U.S. Army Corps of Engineers to dredge shallow harbors. Ferry service between Grand Portage, Minnesota, and Isle Royale National Park was scaled back because one of the company's boats couldn't dock.
Sally Zabelka has turned away boaters wanting to dock at Chippewa Landing marina in the eastern Upper Peninsula, where not long ago 27-foot vessels easily made their way up the channel from the lake's Brimley Bay. "In essence, our dock is useless this year," she said.
Low water has cost the shipping industry millions of dollars. Vessels are carrying lighter loads of iron ore and coal to avoid running aground in shallow channels.
Source
