Cliffs crumble into the sea. (Via YouTube)

In late September, hikers along the North Cornish coast between Godrevy and Porthreath noticed some rocks tumbling into the sea and set up their video to capture the debris falling. They just didn’t expect so much debris to fall.

Around 100,000 tons of rocks crumbled from the cliff, splashing into the sea. Coastal erosion of this magnitude occurs every five years or so, geologist Pete Hobbs of the British Geological Survey told the Telegraph, but it is rarely caught on camera.

No one was harmed in the fall and the cliff had been cordoned off, as geologists can predict when a cliff becomes unstable. The hikers also believed that seals, watching the cliff from the water, managed to avoid any injury.

Most landslides are slow-moving slides, with the earth shifting a few inches each day. Discover magazine posted a video of one such slow-moving slide in June captured in Wyoming. It’s a time lapse video so it seems to go a lot faster than you think. Wait until the guy shows up. We recommend you do not follow his lead.