There are approximately 180 known impact craters in the world, and a good third of them – including some of the largest – are located in North America. These massive explosion zones were formed by meteors, asteroids, and comets that slammed into the Earth’s surface with a force many times greater than that of today’s most powerful nuclear bombs. One of those impacts, dating to about 66 million years ago on Mexico’s Yucatán Peninsula, triggered the mass extinction that wiped out the dinosaurs.
Here are five of the largest and most significant impact craters in North America.
Location: Winslow, Arizona, United States
Impact date: 50,000 years ago
Crater size: 4000 feet in diameter, 700 feet deep
A popular tourist destination, the bowl-shaped Barringer Crater or “Meteor Crater” in Arizona is one of North America’s most recognizable impact craters. It was formed 50,000 years ago when a piece of iron called the Canyon Diablo meteorite struck the earth at an estimated speed of 26,000 mph. The boulder, measuring 100 feet in diameter, was barely slowed down by Earth’s atmosphere and struck with an explosive force exceeding 20 million tons of TNT.
The crater was discovered by white settlers in the 19th century and first identified as a meteor impact site by mining engineer Daniel Barringer in 1903, who noted the concentric pattern of the debris field extending over miles in all directions. The debris includes rock encrusted with microscopic diamonds formed within seconds under the intense pressure of impact. In the 1960s, NASA astronauts trained in the crater for the Apollo missions to the moon.
READ MORE: See photos of astronaut training for the Apollo Moon missions
Chesapeake Bay Crater
Location: Atlantic Ocean near Cape Charles, Virginia, USA
Impact date: 35 million years ago
Crater size: 25 miles in diameter
Discovered only in 1990, the Chesapeake Bay crater is now the largest in the United States. The crater took so long to be found as it is buried under 1,000 feet of rock below the ocean floor of Chesapeake Bay. It was discovered by accident during an offshore drilling project and has since fascinated scientists.
The consensus is that about 35 million years ago, a 1.3 mile meteor or asteroid made up of rock or ice traveling 144,000 mph struck the coastal region. The violent impact triggered a giant tsunami and rained molten debris for miles. The accident left a gash in the earth 12 miles wide and four miles deep, but the sandy crater walls collapsed and eroded over time, resulting in the shallow 25-mile crater. wide today buried under millions of years of sediment.
READ MORE: Deadliest tsunami in recorded history
Location: Lac Manicouagan, Quebec, Canada
Impact date: About 212 million years ago
Crater size: 40 miles in diameter
Known as the “Eye of Quebec”, the Manicouagan crater is the fifth largest impact crater in the world and the only one that is clearly visible from space. Indeed, the Manicouagan crater is not only very large, but its outer ring is filled with water and serves as a hydroelectric reservoir.
A crater of this size required an epic impact event. About 212 million years ago, a meteor measuring more than three miles in diameter crashed into the earth, liquefied the crust as deep as 5.5 miles below the surface. (It took up to 5,000 years for the rock to cool completely.) Scientists believe the fireball created by the impact may have extended to present-day New York City, nearly 800 miles away. , and impact debris has been identified in the UK.
Similar to the meteor that killed the dinosaurs, scientists theorize that the Manicouagan and other Late Triassic impact site may have triggered a mass extinction event that wiped out 60% of species in the area. ‘time.
READ MORE: 30 more seconds may have made all the difference for dinosaurs
Location: Sudbury, Ontario, Canada
Impact date: 1.8 billion years ago
Crater size: 59 km by 29 km
The Sudbury Basin is the oldest known impact crater in North America. There isn’t much to see of the city of Sudbury that could reveal the presence of such a large crater, but there is plenty of underground evidence. Beginning in the 1880s, miners discovered rich deposits of nickel, palladium, copper and other precious metals in Sudbury’s soil, clues that point to a cataclysmic event deep in the region’s past.
Scientists believe it was an icy comet, not a meteor, that struck the earth 1.8 billion years ago and crashed into the shallow coastal waters of an ancient supercontinent called Nuna. The only life on earth at that time were single-celled organisms, so nothing was there to witness the colossal impact, which sent pieces of debris flying into present-day Minnesota, about 750 miles away.
Geologists have found evidence that the force of the impact at Sudbury created huge underground magma fields rivaling some of the world’s largest volcanoes and left a crater that originally measured 93 miles in diameter.
Location: Chicxulub, Yucatán, Mexico
Impact date: 66 million years ago
Crater size: 100 miles in diameter
In the Mayan language, Chicxulub means “devil’s tail,” an apt name for the impact event that forever changed life on planet Earth. About 66 million years ago, an asteroid or comet measuring between 9 and 18 miles in diameter crashed into the Gulf of Mexico with the explosive violence of 100 million atomic bombs and created a fireball that burned at 18,000 degrees Fahrenheit.
Even before molten debris rained down from the sky, igniting endless fires across the globe, a shock wave of air sprayed all plant and animal life within a 1,000-mile radius of the impact site. This was followed by magnitude 10 earthquakes, volcanic eruptions and deadly tsunamis reaching 1,000 feet high.
The deadliest consequences of the asteroid impact took longer to take effect. The collision ejected 100 billion tonnes of sulphate-rich dust into the atmosphere which, along with smoke from the raging fires, blocked out the sun. Global temperatures have dropped 78 degrees Fahrenheit, with temperatures up to 16 years below freezing around the world. The Chicxulub event caused the extinction of 75% of all land and sea species, including dinosaurs.