Killer tornadoes and the dead zoneBy Bob Swanson and Doyle Rice
USA Today; June 12, 2008
Killer tornadoes: The tragic deaths of four Boy Scouts in Iowa brings this year’s tornado death toll to 118, according to the Storm Prediction Center. This makes it the deadliest year for twisters since 1998, when 132 Americans were killed. All of this year’s deaths have occurred in the Midwest, Plains, or South.
Since the weather service began keeping organized records in 1950, the all-time deadliest year for tornadoes in the USA was 1953, with 519 deaths.
Dead zone: The Midwest flooding could eventually also have an impact on the Gulf of Mexico "dead zone," a region of oxygen-depleted water off the Louisiana and Texas coasts that is harmful to sea life. The floods will bring in excess nitrogen down the Mississippi from fertilizer from the farms of the Midwest, according to R. Eugene Turner, a professor at Louisiana State University. "It could keep the dead zone going well into September."
The dead zone usually peaks in mid-summer.
Excess nutrients such as nitrogen can spur the growth of algae, and when the algae die, their decay consumes oxygen faster than it can be brought down from the surface. As a result, fish, shrimp and crabs can suffocate, threatening the region’s commercial fishing industry. A research team led by Turner has already predicted that the dead zone could grow this summer to 10,084 square miles, making it the largest such expanse in at least 23 years.