How to Move a Mountain

TL;DR

Heart Mountain in Wyoming experienced a massive and fast-moving landslide over 45 kilometers, with geologists still trying to unravel the exact cause and mechanism.

Transcript

Thanks to Brilliant for supporting this video. Because you watch SciShow, Brilliant is offering you a 30-day free trial and 20% of an annual premium Brilliant subscription, at Brilliant.org/SciShow. In the late 1800s, a geologist in Wyoming realized that a giant piece of mountain was not where it was supposed to be. Out in the Rockies, at a place c... Read More

Key Insights

• 😃 Heart Mountain experienced Earth's biggest landslide, sliding over 45 kilometers at potentially one-third the speed of sound.
• 🫢 The landslide's exact mechanism is still unknown, but it involved factors like volcanic activity and a possible reduction in friction caused by carbon dioxide gas or fluid-like grains of rock.
• 💨 Similar supersized landslides have been discovered in southwest Utah and on Mars, emphasizing the potential for dramatic and fast-moving geological events.

Questions & Answers

Q: How did Heart Mountain's massive landslide occur?

The exact cause is still debated, but it likely started after volcanic explosions split part of the mountain off, possibly due to a weak layer of rock or volcanic activity destabilizing the area.

Q: Could Heart Mountain's landslide have been buoyed by carbon dioxide gas?

One hypothesis suggests that the heat of the slide vaporized carbonate molecules, creating a cushion of high-pressure carbon dioxide gas that allowed the rock to slide almost frictionlessly downhill.

Q: Did the landslide at Heart Mountain float entirely on a layer of gas?

Some researchers argue that little grains of rock mixed with carbon dioxide, acting like a fluid and reducing the friction that held the mountain in place. This provided a possible mechanism for the slide.

Q: Are events like the Heart Mountain landslide common on Earth?

It is difficult to say, as erosion and plant cover can hide evidence of ancient landslides. However, researchers have found evidence of other supersized landslides on Earth and even on Mars, suggesting they may not be as rare as previously thought.

Summary & Key Takeaways

• Heart Mountain in Wyoming experienced a massive landslide, with ancient limestone scattered across an area bigger than Rhode Island.

• The landslide may have reached speeds of one-third the speed of sound, making it the biggest landslide ever discovered on land.

• Geologists are still uncertain about the exact cause of the landslide, with hypotheses ranging from a weak layer of rock to the vaporization of carbonate molecules creating a frictionless surface.