I’m fascinated by some geological events, including landslides. They happen so rapidly it’s rare to get them on video, but a lucky couple in Cornwall, UK*, were at the right place at just the right time, and caught this amazing footage of several thousand tons of rocks letting go off a cliff face:
Wow! At 12 seconds in, though you can’t see any rock movement, there is a crack in the cliff where debris is getting forced out, falling in a plume. The crack widens, and then WHOOSH!
This was pretty small as slides go (some are longer and move far more slowly). Some are huge, and if they fall into water can cause very, very large tsunamis; for a fun sleep full of nightmares, read up on the Lituya Bay landslide and megatsunami of 1958. Happily, this one in England was far too small to do that sort of thing.
Did you know we see evidence of landslides on Mars and the Moon as well? See the Related posts below, including a couple of shots of avalanches on Mars caught in the act!
And as for the Cornwall slide, I would love to see something like that in person some day… from a nice safe distance. Yowza.
Universe Today is reporting that a recent landslide on Mars looks to be triggered by a small (under 1 meter) rock hitting the surface of the planet. The landslide is less than three years old, and a new impact crater near the top appears to be the culprit.
Go to the UT article to get details. And look at the bigger version there of the image taken by the HiRISE camera; there’s a much larger crater near the bottom of the slide, and you can see where the dust rolled into it and up the far slope of the crater wall, but only partway! It’s yet another amazing shot of the dynamic surface of this nearby world.
The hi-res Lunar Reconnaissance Orbiter’s camera captured a pretty cool image of a (what I’m guessing is an ancient) landslide on the Moon. Check this out:
[Click to embrobdingnangate.]
The slide is down the steep slope of a crater called Marius, located in Oceanus Procellarum, a vast smooth-surfaced area on the Moon (generally called "maria" — singular is "mare" — and easily visible to the naked eye). The crater itself is pretty old; the floor is covered with the same smooth surface as the mare around it, so it predates Oceanus Procellarum which we know is pretty frakkin’ old.
The slide is very interesting; what could have caused it? A moonquake, or a nearby impact? Either way, the ground shook, knocking loose rubble at the crater rim which then rolled downhill. And just to give you an idea of the scale here, the image is 510 meters across: you could walk that distance in a few minutes. The fingers of debris are only a few dozen meters across at most! The smallest objects you can see in this image are less than a meter across.
Features like this on the Moon yield a lot of information. Better, as the LROC page notes, this feature can be compared to similar ones on Mars, giving scientists insight into both worlds.
And? It’s just really cool. Landslides on the Moon! Look out below!
Phil Plait, the creator of Bad Astronomy, is an astronomer, lecturer, and author. After ten years working on Hubble Space Telescope and six more working on astronomy education, he struck out on his own as a writer. He's written two books, dozens of magazine articles, and 12 bazillion blog articles. He is a skeptic and fights the abuse of science, but his true love is praising the wonders of real science.
The original BA site (with the Moon Hoax debunking, movie reviews, and all that) can be found here.
Contact me: The Bad Astronomer "at" gmail "dot" com
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