Asteroid Ocean Impact Wrongly Depicted In Hollywood Movies: Study
An asteroid is set to have a close brush with Earth on Wednesday, April 19. NASA has assured that the space rock will safely pass by our planet, but what happens when asteroids do crash into Earth?
Asteroid Impacts As Depicted In Hollywood Movies
Hollywood depicts such asteroid impacts as a catastrophic event. The movies shows that when extraterrestrial rocks hit the middle of the ocean, they produce tsunamis that can wipe out coastal cities. New simulations, however, show that real asteroids do not create such as splash.
Asteroids are most likely to hit the ocean because our planet is mostly covered by water. To determine the possible impact of asteroids that can potentially crash into our planet, Galen Gisler, from Los Alamos National Laboratory, conducted 3D simulations that model wave formation from falling rocks of different sizes.
Real Asteroids Terrible At Producing Waves
After running 11 simulations of asteroids with diameters of less than 500 meters over a period of several months, he found that the waves that can be produced by smaller asteroids are comparable to landslide tsunamis on Earth.
Although space rocks can drop straight down into the ocean, there are high chances that these objects will get into the water at an angle. As a result, more water will be pushed in front of the object than behind it, and Gisler wanted to know how this would affect formation of waves.
The simulations revealed that asteroids are terrible when it comes to producing waves. The researcher discovered that 80 percent of the energy from the impact goes to vaporizing water and forming a crater. The rest of the energy is spent throwing most of the water up into the atmosphere, where this can potentially affect weather patterns.
Gisler estimated that only a tenth of 1 percent of the impact's kinetic energy is spent for wave formation. He noted that the waves can still be relatively massive albeit they can dissipate quickly.
Rocks that measure at least 140 meters are the ones that are most likely to cause significant problems. Larger rocks that measure about 300 meters can produce hurricane-force winds, localized waves, and shock waves in the air.
The space rock set to pass by Earth this week, dubbed Asteroid 2014 JO25, is estimated to be a little over 600 meters in size.
Gisler also added that if an asteroid impact occurs within 100 kilometers or so off the shore, it would have dramatic impact on the coast.
If the space rock splashes down farther from the coast, though, the waves that it would produce would quickly break up in the open ocean.
"If you're more than 100 kilometers from a shoreline, I would be tempted to say let the thing drop and study it," Gisler said.
Gisler compared this effect to waves generated by landslides around fjords in Iceland and Norway citing that materials that slide down the mountains into the long and narrow inlets produce massive waves that, although produce large local effect, do not spread very far.