The chances are real, and both are threatening the planet Earth. Apophis and Yellowstone have been appearing in the media lately. The chances of a catastrophic event occurring in your lifetime are higher than you may think.
Russian astronomers are predicting that the asteroid Apophis could collide with the planet earth on April 13, 2036, writes the online Voice of Russia.
Apophis’s length was earlier estimated to be 450 metres, but a better estimate based on spectroscopic observations at NASA’s Infrared Telescope Facility in Hawaii puts it at 350 metres. That’s still a big rock to be hit by.
‘Apophis will approach Earth at a distance of 37,000 – 38,000 kilometers on April 13, 2029. Its likely collision with Earth may occur on April 13, 2036,’ Professor Leonid Sokolov of the St. Petersburg State University said.”
According to Wikipedia, NASA has estimated the energy that Apophis would release if it struck Earth as the equivalent of 510 megatons on TNT. By comparison the impacts of the Tunguska event is estimated to be in the 3–10 megaton range. The 1883 eruption of Krakatoa was the equivalent of roughly 200 megatons, and the Chicxulub impact, believed by many to be a significant factor in the extinction of the dinosaurs, has been estimated to have released about as much energy as 100 million megatons.
The bad news is that an impact by Apophis would destroy an area of thousands of square kilometres, and seriously disrupt the climate for a few years. The good news is that it would be unlikely to have long-lasting global effects. Also the chances of Apophis actually striking the earth are still remote.
The other potential natural catastrophe is the Yellowstone super-volcano, reports National Geographic here. Yellowstone’s caldera covers a 40 by 60 kilometer swath of Wyoming, is an ancient crater formed after the last big blast, some 640,000 years ago. The magnitude of an eruption estimated by scientists would be 1000 times more powerful than the 1980 Mount St. Helens eruption of 1980, and would lead to dire consequences for the globe.
See: “When Yellowstone Explodes“ in National Geographic magazine. Here’s how the last one looked:
Scientists calculate that the pillar of ash from the Yellowstone explosion rose some 100,000 feet, leaving a layer of debris across the West all the way to the Gulf of Mexico. Pyroclastic flows—dense, lethal fogs of ash, rocks, and gas, superheated to 1,470 degrees Fahrenheit—rolled across the landscape in towering gray clouds. The clouds filled entire valleys with hundreds of feet of material so hot and heavy that it welded itself like asphalt across the once verdant landscape.”
The Yellowstone crater today is rising at a record speed, forced up by a huge magma reservoir that is thought to be about 10 km below the surface, see below. It has risen 25 centimeters since 2004. NatGeo writes that roughly 3,000 earthquakes occur in Yellowstone each year.
But between December 26, 2008, and January 8, 2009, there were about 900 earthquakes, and the rate of rise then slowed for a time. Scientists believe the earthquakes may help to release pressure on the magma reservoir below the surface by allowing fluids to escape, and thus relieve some pressure.
Yellowstone erupted 3 times in the last 2 .1 million years. The last eruption was about 640,000 years ago. German online FOCUS magazine writes:
The Yellowstone volcano is considered to be dangerous because on a geological timescale, it is due to erupt.”
Yellowstone is not the only super-volcano threatening the planet. A FOCUS map shows 6 others. Although the chances are small that any one in particular will erupt soon – maybe 1 in a 1000, the odds increase to worrisome levels when all the catastrophe possibilities get factored in. If one identifies 10 potential catastrophic events, each with the odds of occurrence being 1 in 1000, then it means the odds of one happening reduce to 1 in a 100. That starts to get worrisome. It means there’s a pretty good chance one catastrophe will occur in the next 100 years.
People who were born just recently have a pretty good chance of witnessing such an event in their lifetime. And the longer the planet goes without a catastrophe occurring, the greater the chances become.