Barringer Crater

The impact of the meteor with earth occurred about 50,000 years ago. Currently, the crater is about a 1.5 kilometers in diameter (slightly less than mile), and some 170 meters deep (570 feet). A 30 meter high rim of rock surrounds the crater and distinguishes it from the surrounding plains. At the time of the impact, the climate on the Colorado Plateau[?] was cooler and damper. The area was a grassland dotted with woodlands, and inhabited by wooly mammoths, giant ground sloths[?], and camels.

At the time of impact an iron-metallic meteor about 50 meters across fell from the sky, burning much brighter than the Sun, at a speed faster than 40,000 kilometers per hour (KPH). The object slammed into the ground, producing a massive explosion that was about three times more powerful than the Tunguska event. The explosion dug out 175 million tonnes of rock and left a crater about 1,200 meters across and 170 meters deep. The shock of impact propagated as a hemispherical shock wave that blasted the rock downward and outward from the point of impact, forming the crater.

At ground zero, the impact melted everything that it did not vaporize, and transformed carbon minerals into diamonds (and also lonsdaleite, a form of diamond found only here and in Arizona's Canyon Diablo[?]). 30 tonne blocks of limestone were tossed outside the crater's rim. The shock of impact sped through the ground, resulting in a magnitude 5.5 earthquake.

Everything within a radius of three to four kilometers was killed immediately. The fireball that formed should have scorched everything within a radius of ten kilometers. A shock wave, moving out at 2,000 KPH, leveled everything from 14 to 22 kilometers, dissipating to hurricane-force winds that persisted to a radius of 40 kilometers. Despite this destruction, the Barringer impact did not throw up enough dust to affect the Earth's climate. The area was likely recolonized by the local flora and fauna within a century.

Discovery

Settlers in the American West had found a great crater in the barren lands of the Colorado Plateau in northern Arizona, about 55 kilometers east of Flagstaff. Some geologists believed it was a volcanic crater, but in 1905 a mining engineer and businessman named Daniel Moreau Barringer[?] suggested it was the result of the impact of a large iron-metallic meteorite. Later research by Gene Shoemaker would prove him right, as the crater was lined with materials showing the effects of the enormous pressures and high temperatures associated with an impact event. It the first site to be proven to be formed by the impact of an object from outer space.

At the time of discovery by the Europeans, the surrounding plains were covered with about 30 tons of oxidized iron chunks from the meteorite. Barringer spent 27 years trying to mine the crater and find iron, which he believed to have been left by the meteorite. However, as the meteorite had vaporized on impact, no significant deposit was ever found.

External Link

• Barringer Crater official site (http://barringercrater.com)