In contrast, large meteorites are not significantly impeded by the atmosphere and may strike the ground with greater velocities tens of kilometers per second. An excellent example of a crater produced by this type of impact is the geologically young 50, year old Meteor Crater in northern Arizona. This crater is 1. Numerous fragments of Canyon Diablo, the iron meteorite responsible for making the crater, have been found in the area.
These fragments range in size from minute particles to pieces weighing over pounds; the total mass of material found so far is over 30 tons 2. Aerial view of the impact crater and the sinuous Canyon Diablo which cuts through the Colorado Plateau across the top of the image. Because meteorites are named after geographic features, the iron meteorite remnants of the asteroid that produced Meteor Crater are called the Canyon Diablo meteorite. When the Canyon Diablo iron meteorite struck the plateau region it produced a huge explosion.
Within a fraction of a second, large portions of the meteorite and plateau sediments were vaporized. Small, surviving fragments of the meteorite were mixed with shocked sediments and ejected from an expanding crater. Some of the sediment was ejected as fine-grained particulate debris and deposited for some distance around the crater.
Large blocks were also ejected, particularly near the rim of the crater, where they were simply overturned. Within a few minutes the vast hole in the plateau was completely excavated, the rocky ejecta had landed, and the cloud of vapor that had risen above the crater was already dissipating.
In the case of large impacts, where a significant portion of the targets are melted, molten droplets may also be ejected from the craters. This impact occurred roughly between 10, and 30, years ago. The Lonar Lake in Maharashtra, was formed about 50, years ago when a meteorite hit the surface. The saltwater lake that evolved in the resulting basaltic rock formation has a mean diameter of 1. The crater itself is a fun trek and the surrounding vegetation is a treat for birdwatchers. The present dimensions of the crater are approximately meter 1, feet in diameter by 34 meter feet deep.
The impact probably occurred about a million years ago. Because of the extreme arid conditions of the area the crater is still clearly visible. By its size and morphology, the Monturaqui crater presents many similarities with the Bonneville crater on Mars explored by the Spirit rover in Both craters are shallow, the size of the blocks ejected near the crater rim are similar, and both were formed in a volcanic environment.
Located near the center of Australia , the Gosses Bluff crater is thought to have been formed by the impact of an asteroid or comet approximately million years ago. The eroded crater is 6 km 4 miles across, but at the time of impact it would have been around 22 km 14 miles in diameter. The site is known as Tnorala to the Western Arrernte Aboriginal people, and is a sacred place. The Tswaing Crater was created by a chondrite or stony meteorite, some 30 to 50 meter in diameter, that hit the earth about , years ago.
In the center of the crater is a small lake which is filled by a spring and rainwater. Stone tools from the stone age show that the crater was regularly visited by people in order to hunt and collect salt. The Pingualuit Crater was created about 1.
The 3. The lake at the bottom of the crater has a depth of meter feet and contains some of the purest water in the world. The lake has no inlets or apparent outlets, so the water accumulates from rain and snow and is only lost through evaporation. That was followed by magnitude 10 earthquakes, volcanic eruptions and killer tsunamis up to 1, feet tall. The deadliest consequences of the asteroid impact took more time to take effect.
The collision ejected billion tons of sulphate-rich dust into the atmosphere that, along with the smoke from raging fires, blocked out the sun. Global temperatures dropped by 78 degrees Fahrenheit, with up to 16 years of subfreezing temperatures worldwide.
The Chicxulub event caused the extinction of 75 percent of all species on land and sea, including the dinosaurs. But if you see something that doesn't look right, click here to contact us! Twice a week we compile our most fascinating features and deliver them straight to you.
Live TV. This Day In History. History Vault. Here are five of the biggest and most significant impact craters in North America.
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