Iowa Town's Meteor
Blast Dwarfs "Armageddon"
By Greg Smith
Associated Press Writer
"The force of the blast was more than if you took 10 times all the nuclear weapons on Earth at the height of the Cold War, piled them in one spot and set them off."
MANSON, Iowa -- As "Armageddon" hits the big screen, it isn't going to make a deep impact among folks here: They already have their own extraterrestrial claim to fame in the form of a 24-mile-wide crater formed some 74 million years ago when a huge meteorite slammed into north-central Iowa and turned the region into a giant killing field.
Geologists say it's the second-largest crater in the continental United States and 15th-largest in the world.
"Armageddon," the asteroid-vs.-Earth movie that is in the middle of its debut weekend, has been heavily promoted across the nation. And "Deep Impact" has grossed $135.8 million since its debut May 8.
But in Manson, a town of 1,924 people that doesn't even have a movie theater, nobody much cares.
"I'm not into that kind of stuff," said Ann Schlapkohl, the librarian at the Manson Community Library. "The real thing is in our back yard."
Bernadine Zehl, who helped the town kick off its inaugural Crater Days celebration last weekend, agrees: "This was a natural happening. It wasn't anything conjured up by Hollywood -- or even Steven Spielberg."
The Manson Impact, as geologists call it, was the real, horrible thing.
"Basically, anything alive in the central part of North America would have been killed by the shock wave," said Ray Anderson, a geologist with the Iowa Department of Natural Resources Geological Survey. "The electromagnetic pulse -- the heat from the blast that went out -- would have basically set everything in the state of Iowa on fire in an instant. ... All the dinosaurs in the central part of the United States would have been killed by that blast."
In the continental United States, only the crater left by a meteorite 35 million years ago at Chesapeake Bay is larger than the Manson Impact, according to Peter Schultz, a geology professor at Brown University.
At Manson, Anderson theorizes the meteorite was traveling at 60,000 mph when it hit. The impact was about 3 1/2 miles deep, and as it bore into the earth, the sides of the crater were lifted 1 1/2 miles high from the earth's surface.
"The force of the blast was more than if you took 10 times all the nuclear weapons on Earth at the height of the Cold War, piled them in one spot and set them off," Anderson said.
Besides the environmental devastation, the blast turned topsy-turvy the rock formations below the Earth's surface in the Manson area.
Granite and other rocks normally found several thousand feet below ground were brought up to within less than 200 feet of the surface and were discovered after the turn of this century, Anderson said.
With all that destruction, no telltale signs of the huge crater exist.
Glacial deposits have filled in the crater while erosion has leveled it off, Anderson said. What would be the lip of the crater is about 200 feet below the rich farmland, he said.
"Researchers have used satellite imagery, radar imagery, everything. But there is no surface expression," Anderson said.
That leaves the locals wondering how to show off their extraterrestrial prize.
"Every once in a while someone will come to town and expect to see the crater, or they want a piece of the meteorite," said Schlapkohl, the librarian. "It's really hard to explain to them that there's really nothing to see."

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