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A gigantic landslide shows the limit to how high mountains can grow
- vient 3y agohttps://archive.is/oO0dC https://archive.is/oO0dC
- swader999 3y agoArticle didn't mention it but lightning is a significant force in mountain erosion too.
- PNewling 3y agoI don't think I have ever heard of this, have any more details?
- trillic 3y agoThere's water in the rocks. When it rains water gets trapped between rocks and layers of rock. Then a storm comes in, more water, water is flowing filling cracks, pooling wherever it can, lightning strikes, the water trapped in and around some of the rocks very quickly heats up, turns to steam, and kaboom, you now have moving rock. Presumably lightning strike erosion is a lot of energy over a short time compared to wind or water erosion which is much less energy but over much longer periods?
- defrost 3y agohttps://www.nationalgeographic.com/science/article/140105-lightning-mountains-south-africa-drakensberg-mountains-geology https://www.nationalgeographic.com/science/article/140105-li... https://ui.adsabs.harvard.edu/abs/2016EGUGA..1815451H/abstract https://ui.adsabs.harvard.edu/abs/2016EGUGA..1815451H/abstra... etc. There are some high resolution nightside lighting storms from orbiting camera compilations on youtube that might impress just how much power zaps down in strikes.
- trompetenaccoun 3y agoUnless their definition of "significant" is my definition of insignificant, it's not true.
- EdwardDiego 3y agoI've been camping on a mountainside when a storm came over at night and rocky outcrops on the ridge above us were struck repeatedly by lightning. In the morning, clear blue skies, and we climbed up to have a look. Was sadly not very dramatic, we were expecting chunks of rock blown off, but you could see that the sudden heat had created fresh fissures, and around what we thought was the ground zero of a strike, the surface of the rock had become friable for a few centimetres. But water/ice is always going to be a dominant feature in rock wasting, those lightning cracks just give it easier ingress.
- bradrn 3y agoPaper: https://doi.org/10.1038/s41586-023-06040-5 https://doi.org/10.1038/s41586-023-06040-5
- akiselev 3y agoBefore anyone gets excited, the landslide occurred in the 12th century or so :( I was all excited to plan a rock hounding trip to the Himalayas. I even sent out the Sherpa bat signal (it’s a silhouette of me shaving a Himalayan yak), only to find out I’m eight hundred years too late.
- Mordisquitos 3y agoGiven it happened well within recorded history I was excited to see if there were any contemporary accounts of the event, but disappointingly the article doesn't cite any, nor does it indicate whether there has been research on that facet. However remote in the Himalayas it may have been, surely such a cataclysmic landslide must have been felt and heard a significant distance away.
- dboreham 3y agoSmaller mountain landslides do occur in modern times. There was one here in Montana in 1959 that killed 27 people and blocked a major river. The effects are still visible today. https://en.wikipedia.org/wiki/1959_Hebgen_Lake_earthquake https://en.wikipedia.org/wiki/1959_Hebgen_Lake_earthquake
- sjkoelle 3y agothe huascaran landslide too
- pixl97 3y agoI mean the 'biggest' landslides are so big I'm not sure we'd fully be aware if one was going to happen soon. https://en.wikipedia.org/wiki/Heart_Mountain_(Wyoming) https://en.wikipedia.org/wiki/Heart_Mountain_(Wyoming) >Between 50 and 48 million years ago a sheet of rock about 500 square miles (1,300 square kilometers) in area detached from the plateau south of the Beartooths and slid tens of kilometers to the southeast and south into the Bighorn and Absaroka Basins Luckily events like this are geologically rare. A bigger risk would be tsunamis from underwater mountain landslides.
- gumby 3y ago
- jmclnx 3y ago> As the rubble crashed down, the energy released would have been equivalent to around six times that of the Tsar Bomba Interesting, wonder if this Approx 1190 event had a global impact. https://en.wikipedia.org/wiki/Medieval_Warm_Period https://en.wikipedia.org/wiki/Medieval_Warm_Period Seems that ended in 1250, coincidence ??
- gumby 3y ago> … the energy released would have been equivalent to around six times that of the Tsar Bomba But how does that compare to an Olympic swimming pool full of double decker omnibuses being dropped from the same height?
- kennyadam 3y agoThe lengths people will go to to avoid using the metric system!
- gumby 3y agoI think the Tsar Bomba was designed metric (unlike the contemporary US bombs and space program) so perhaps it was chosen for that reason?
- dylan604 3y agoThey go in increments of 50m. If you asked the width people go to, it would be 25m. So your comment about avoiding the metric system is not really accurate. We don't say the Earth is approximately equal to 150 million kilometres from the Sun, we say one AU. We just use numbers that can be comprehended.
- mint2 3y agoAn ancestral mount Shasta in California collapsed sending a debris flow 28 miles covering something like 675sq km
- davely 3y agoSpeaking of California, the Blackhawk Slide[1] in Southern California is pretty impressive. It occurred ~18,000 years ago and the landslide escarpment is still clearly visible today! [1] https://blogs.agu.org/landslideblog/2019/11/15/the-blackhawk-landslide/ https://blogs.agu.org/landslideblog/2019/11/15/the-blackhawk...
- mjb 3y agoFor comparison, this is between 4 and 5 times larger than the Osceola Mudflow (https://en.wikipedia.org/wiki/Osceola_Mudflow https://en.wikipedia.org/wiki/Osceola_Mudflow) that formed the 550km² of fertile plains around the south end of Puget Sound (near Seattle) and knocked a huge chunk out of Mount Rainier. If you drive from Auburn to Enumclaw, for example, notice how flat the land is and think about how that was hilly Cascade foothills and glaciated drumlins until 5500 years ago. The Osceola event was way bigger than Mt St Helens, and this one in the Himalayas was way bigger even that that. Back-of-envelope, that Osceola event released about 10^19 Joules of energy*. The scale of these things is absolutely incredible. According to my father, until around the time he was doing Geology at university (late 1960s), the consensus was that these kinds of events (and mass wasting more generally) were geologic processes that no longer happened (and hadn't really happened throughout the Holocene). I don't know the history in detail there, but it does seem true that only relatively recently we've had a real appreciation for how active Earth's geology still is. * 4e15 cubic centimeters of material, 2 g per cc mix of rock and ice, mean elevation change 1000m
- mjb 3y agoRelated, there's a cool transition if you hike up the Greenwater river (starting at the town of Greenwater, heading towards FS70) there's a cool transition where the geology switches from Osceola mud to the more typical Cascade foothill geology (about half a mile from the White river).
- Jun8 3y agoI think the title is off: the theoretical limit of how high a mountain can be on a rocky planet of given size can be found by physical considerations. The geological and other factors come into play, too to make the practical limit much smaller than the theoretical one.
- JamesLeonis 3y ago> Examining the surrounding cliffs for signs of a collapse, he noticed that a peak known as Annapurna IV offered a relatively smooth, steep face which seemed to fit. I was interested in what the mountain looked like, and found a whole page dedicated to it [0]. In the picture of the west side you can see the steep face. The altitude map also has an unusually large flat area to the west of the mountain. [0]: https://nepalhimalpeakprofile.org/annapurna-iv https://nepalhimalpeakprofile.org/annapurna-iv
- varjag 3y ago> Enough rock fell off a Himalayan peak to bury Paris to the height of the Eiffel Tower > The falling mountain top would have displaced up to 27 cubic kilometres of rock—roughly enough to bury the entirety of Manhattan to about the height of the Empire State Building. It's paywalled then on but I assume it's also enough rock to bury Dubai to the height of Burj Khalifa.
- no_butterscotch 3y ago> It's paywalled then on but I assume it's also enough rock to bury Dubai to the height of Burj Khalifa. Haha lol. These comparisons are always strange when I read them or see them in documentaries. "That's enough X to stretch all the way to the moon and back!" In other words it's a lot. "No you don't understand! It's not just a lot! It's enough that if unraveled it could stretch around the Earth 10 times!!!"
- placesalt 3y agoNon-paywalled article: https://arstechnica.com/science/2023/07/massive-peak-collapses-may-reshape-himalayas/ https://arstechnica.com/science/2023/07/massive-peak-collaps...
- ReptileMan 3y agoI am always amazed how thin the biosphere is - 3km down in the water , 3 up in the air - so roughly 1/1000 of the radius of the earth. And the vast majority of the biomass could probably be found in couple of hundred meters close to water level.
- olddustytrail 3y agoI seem to recall reading that there is actually more biomass below the surface of the earth than above, so you might be wrong on that one.
- idlewords 3y agoThere is stuff living in rocks down to about 4km depth (the limiting factor is heat), including far below the seafloor. It's still an open question whether this biomass, some of which has been out of contact with the surface for hundreds of millions of years, exceeds the biomass of surface on Earth, but it's at least in the same ballpark.
- justrealist 3y agoIt's kind of ambiguous how "alive" that biomass is as compared to life on the surface. If a bacterium reproduces every 10,000 years, how "alive" is it?
- fractallyte 3y agoI wonder if this is related (in a very large scale sense) to the sand pile model and self organized criticality... https://en.wikipedia.org/wiki/Self-organized_criticality https://en.wikipedia.org/wiki/Self-organized_criticality The sand pile model: if one builds a pile of sand, dropping onto it a small number of grains at a time, individual grains will slide down the slope - but there's a critical angle at which any additional grains can trigger a catastrophic avalanche. https://nautil.us/the-math-of-the-amazing-sandpile-238320/ https://nautil.us/the-math-of-the-amazing-sandpile-238320/
- hinkley 3y agoIf one builds a dry pile of sand. A wet pile of sand has a different angle of repose. Between the lubrication and the rather substantial weight of the water, that's how most mudslides happen.
- mcdonje 3y ago>In geology, unlike business, nothing is too big to fail. Nothing is too big to fail in the business world either. Or at least nothing should be. If a business is that important to the economy but it can't keep itself afloat, something has gone horribly wrong on the business side, the government side, or both. Bailing out the business will probably not fix the underlying issues.
- tjr225 3y ago[dead]
- dendrite9 3y agoThe Sabche Cirque in question looks like a fascinating, and difficult place to explore. Check out narrow the exit drainage is! https://www.researchgate.net/figure/Deep-and-narrow-gorge-of-the-Seti-River-at-the-outlet-of-Sabche-Cirque-Avalanches-and_fig2_354413412 https://www.researchgate.net/figure/Deep-and-narrow-gorge-of... This Nasa blog post has a lot of good pictures of the immediate area that helps with understanding the shapes of the mountains there. I initially didn't realize just how choked down the drainage got. It seems like many cirques are described as having narrow exits but rarely are they this narrow. https://earthobservatory.nasa.gov/blogs/fromthefield/2014/01/ https://earthobservatory.nasa.gov/blogs/fromthefield/2014/01... Here's an earlier discussion related to this one: https://www.science.org/cms/asset/b7f5337c-0f34-4fb5-a907-612e8c35ec09/pap.pdf https://www.science.org/cms/asset/b7f5337c-0f34-4fb5-a907-61...
- kabdib 3y agoMy dad attended college in the 1950s. I liked reading his old textbooks. The geology texts that predate plate tectonics are . . . interesting. They really didn't know where volcanoes and mountains came from.
- lawkwok 3y agoWhat were the prevailing theories at the time?