A Bad Day to be a Dinosaur

 

Incoming!

ABOUT 66 million years ago, dinosaurs of many different shapes roamed the Earth. If you were a dinosaur, you’d be rather happy with your environment, and blissfully unaware of the fact that the story of your species was about to come to a dramatic end – George R. R. Martin style.

Hurtling through space at a speed of 72,000km/h – a speed at which you could go around the entire Earth in a little over ten minutes – an asteroid had its sights set on the third planet from the Sun.

This particular celestial body, left over from the creation of our solar system, was about 10km across, and had a similar density to aluminium.

About 66 million years ago, the last day of the Mesozoic era, was the last day that most dinosaurs would roam the Earth.

The formation of a crater // Animation by David Fuchs.

Impact!

The asteroid collided into the Earth with devastating effect, landing in what we now call the Yucatán Peninsula, in southeast Mexico. The Chicxulub Impactor – named after the now nearby town – created an explosion that was 37.4 billion times more powerful than the Hiroshima nuclear bomb. Yes, that was billion, as in 37,400,000,000.

Using the Impact Calculator website, we can determine the effects of these ‘end-of-days’ asteroid events and can imagine what it would have been like to be there.

Let’s pretend you were there on this day. Spoiler alert: you’re not going to survive. If you weren’t out swimming in the lovely Yucatán Peninsula waters where the asteroid created an incredible 163km-wide crater, then unfortunately your demise would have been much worse. Almost 9,500 cubic kilometres of dirt, rock and water from the impact zone was instantly melted or vaporised, meaning a quick end to your story.

What if you were further away? If you were about 250km away, which is roughly the distance you’d have to travel to get from Melbourne to Wangaratta, would you even know it had happened?

Explosion!

Turns out, after seeing the fireball – which, mind you, would have a radius of 225km and would appear 204 times larger than the Sun – you would have about 11 seconds before an intense heatwave hits you. This thermal radiation would be so hot, that your clothes would instantly ignite, as well the trees and the grass around you.

However, for the sake of curiosity, let’s pretend that you’re some enhanced cyborg with the power to withstand third degree burns to your entire body. You would then have another 40 seconds to survey the hellish landscape surrounding you before a 10.3 magnitude earthquake hits. This earthquake would be more powerful than anything ever recorded in human history. The Mercalli Scale suggests that “most masonry and frame structures [would be] destroyed”. In other words, total carnage.

Velociraptors, with a top speed of 64km/h, would not have been able to outrun the ejecta cloud // Photo by Eduard Solà Vázquez.

It’s not over yet!

Still standing? The ejecta cloud is on its way! By the time it reaches you – which only takes just under 4 minutes – this blanket of matter thrown outwards from the impact will be travelling at over 3,900km/h, and will have an average thickness of 56 metres. That’s higher than an 18-storey building. With an average fragment size of 11cm where you are – think hail, except superheated and made of rocks – simply putting up your umbrella won’t protect you.

If, by some miracle, you found a structure that hadn’t been destroyed yet, and you were taking shelter, you’d have about another 8 minutes until the blast of air arrives. But this isn’t any ordinary gust of wind; it’ll have a speed of 7,800km/h, and will effectively level anything that is left standing. Buildings? Gone. Bridges? Collapsed. Trees? Up to 90% would be blown away, and the rest would no longer have branches or leaves. You’d also be thankful if you had a good pair of earmuffs, since the sound of the air blast would reach 137dB, which is just short of the threshold of pain in humans.

In short, let’s cross our fingers and hope that no asteroids have us targeted in the near future.

 

Cover image by Donald E. Davis, NASA.

16 Responses to “A Bad Day to be a Dinosaur”

  1. Thanks Stephanie! I’m no expert at this, but there were definitely creatures that managed to survive the extinction – I think mostly avian and marine animals. A recent study looking at the climate after this event was analysing fish debris fossils to determine their oxygen isotope compositions (which have a correlation with temperature), so those guys found a way to survive!

  2. Interesting post. Really liked the mental imagery, putting us in the dinosaur’s shoes E.g: “If, by some miracle, you found a structure that hadn’t been destroyed yet…”

    Just wondering, how would any creature survive this apocalypse? Afterall, I think birds descend from dinosaurs. Please correct me if I am wrong.

  3. Glad you like it! I can’t say for sure, but I would suspect that some creatures would have survived the collision itself. However (and I hope to follow this up in another post), even though the asteroid caused massive instantaneous destruction, the K/T extinction was mainly due to the vast and rapid change in the Earth’s climate resulting from the asteroid’s collision!

  4. Samuel Stefanus says:

    Your gif is brilliant! I really like how the flow of your article makes it easy to understand. Just wondering whether any living creatures survived that collision (bacteria probably?).

  5. Thanks heaps for reading it, Michael! I really appreciate it!

  6. Michael Taylor says:

    Really engaging read Connor, I loved it! 🙂

  7. Don’t think so, Stu, but you’d sure make an interesting fossil! Thanks for the feedback, I’m glad you liked it!

  8. Stuart Trainer says:

    Does having a titanium spine count for being a cyborg who can withstand burns?

    A really interesting read. A surprising amount of information delivered in a fun and memorable way.

    I think the strongest aspect of this article is how it addresses something as apocalyptic as an earth destroying meteor in a lighthearted and humorous fashion.

  9. Thanks Veronica, I appreciate it!

  10. Veronica Voo says:

    This is such an engaging post! Love the animation.

  11. It’s remarkable how quickly it all happened! Thanks for reading, Tyler!

  12. Tyler Sudholz says:

    Wow that’s intense!
    I was quite alarmed by some of the comparisons you made to time-frames, sizes and events that we can understand – it really puts into context how significant it was!

  13. Thank you Sarah! I’m glad you found it engaging! I didn’t know about any of those details, either, before I started looking into it. It was a lot of fun to research and write about!

  14. Sarah Casauria says:

    I loved this post! So engaging and really informative about details that I didn’t know about such as the massive wind gusts and the thermal radiation 🙂

  15. Thanks Holly, glad you enjoyed it! The gif makes it really easy to picture the event, doesn’t it?

  16. Great article, I love the gif!

    Sara Phillips was right, dinosaurs always make a killer story!