Doomsday Preview: Supercomputer Simulates Asteroid Impacts

By Nathaniel Scharping | December 14, 2016 2:34 pm

(Credit: Los Alamos National Laboratory)

If, or perhaps when, an asteroid strikes the Earth, it will likely end up in Davy Jones’ locker.

Our planet’s surface is 70 percent water by area, and an aquatic impact would create a sizable tidal wave that could do some serious damage if it hits a populated area. But apocalyptic visions of the devastation resulting from an asteroid strike may be slightly overblown, say scientists at the Los Alamos National Laboratory.

The team used a supercomputer-assisted model to simulate the outcomes of various types of impacts, creating a series of visualizations depicting the aftermath. Along with the size of the rock and angle of impact, the biggest factor in determining the potential for destruction is whether the asteroid breaks up before hitting the surface, or what’s called an “airburst.”

Breaking up before smacking Earth would spread the asteroid’s impact across a wider area, reducing the size of the splashdown and the waves that it would generate.

Even if an intact asteroid does hit the surface, the waves it creates will spread outward in an ever-widening circle, like massive versions of the rings formed by dropping a pebble into a pond. While they could still be dangerous, these circular disturbances wouldn’t be as powerful as the line waves created by earthquakes and underwater landslides.

The researchers say they would probably only be as strong as the waves generated by tropical storms. If an asteroid hit within 10 or so miles of a populated area, though, that’s a different story. The waves may dissipate quickly, but they would still be large enough to wreak some Hollywood-size havoc.

The researchers presented a paper detailing their findings this week at the meeting of the American Geophysical Union.

The more salient danger from an asteroid hitting the ocean would probably be the massive plume of water shooting into the air, the researchers say. Depending on the rock’s size, as much as 250 megatons of water could be forced into the atmosphere. Some would fall back quickly, but enough would be vaporized that clouds of water would hang around in the stratosphere for months or even years.

Water vapor traps heat on Earth, making it a powerful greenhouse gas. Instead of city-leveling tsunamis, our biggest worry from an asteroid impact might be getting cooked.


(h/t Gizmodo)

CATEGORIZED UNDER: Space & Physics, Technology, top posts
  • Uncle Al

    Anything incoming with 500 gigatons is its own phenomenon. Atmospheric breakup Mach stem flattens a continent. Landing may breach the mantle or temblor flatten a continent. Hot debris blasted into the atmosphere will re-enter hot and fast (above 233 C), igniting a continent.

    I suggest detonating a depleted uranium-jacketed Tsar Bomba at the bottom of Lake Michigan to watch what happens in Detroit, as model. Nobody is using that city anyway. The Chelyabinsk meteor was a pussycat.

    From the paper, “lofting as much as 250 metric megatons of water into the atmosphere.” “At any moment, the atmosphere contains an astounding 37.5 million billion gallons of water, in the invisible vapor phase.” (CRC Handbook suggests 6.34×10^20 gal.) 66 billion gallons lofted is less than 2 ppm increment worst case. bfd for that.

    • OWilson

      New York Times headline.

      “Asteroid strikes earth. Women and minorities at greatest risk!”

    • boonteetan

      Well said. Except one would not buy the idea of using Detroit as a model.

      • Uncle Al

        Wjhy not rrade Detroit for an immediate end to Global Warming? Merely don;t give any advance warning so nobody is emotionally distraught, then say the Russians did it

        • 7eggert

          Instant nuclear winter …

    • Allen Lewis

      water vapor creates clouds that reflect sun light and would cause global cooling not global warming if there was a massive amount of water sent ito the stratosphere by an ocean strike.

      • Deuce_2112

        you are aware that water vapor is the number one greenhouse gas in terms of volume, raw tonnage, and overall effect, yes?

  • jeff

    a Russian hack is to blame

  • stargene

    Notice the interesting back-reaction in certain impacts, where some
    of the pressure/energy/water propagates back along the original path
    of the asteroid. Possibly facilitated by a lower density or pressure
    channel created by the passage of the asteroid?

    • stargene

      Ok… a quick email query got a reply from one of the team: [when the] “…CS team […] first saw the material shooting back along the incoming path we thought there was something wrong within the data. It just didn’t make sense. Gisler explained that the asteroids are coming in so fast and so hot that they leave a vacuum in their path. What you see is the asteroid and water being sucked up into that vacuum…” Verrrry cool.


    A powerful computer we called super computer. Today we like to talk about high quality computer which we can’t thinking before 20 years ago.So i think day by day we can find another super computer which give us more facilities.


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!


Briefing you on the must-know news and trending topics in science and technology today.

See More

Collapse bottom bar