[HN Gopher] A gigantic landslide shows the limit to how high mou...
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A gigantic landslide shows the limit to how high mountains can grow
Author : jesterpm
Score : 97 points
Date : 2023-07-06 14:05 UTC (8 hours ago)
(HTM) web link (www.economist.com)
(TXT) w3m dump (www.economist.com)
| varjag wrote:
| > 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 wrote:
| > 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!!!"
| vient wrote:
| https://archive.is/oO0dC
| dendrite9 wrote:
| The 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...
|
| 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...
|
| Here's an earlier discussion related to this one:
| https://www.science.org/cms/asset/b7f5337c-0f34-4fb5-a907-61...
| ReptileMan wrote:
| I 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.
| idlewords wrote:
| There 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 wrote:
| It'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?
| olddustytrail wrote:
| I 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.
| akiselev wrote:
| Before 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 wrote:
| Given 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.
| gumby wrote:
| I can't say I am sympathetic about you having missed this
| Himalayan landslide. If you dawdled, it's not my problem.
|
| But if you're willing to travel to the Alps, here's one from a
| couple of weeks ago:
| https://www.theguardian.com/world/2023/jun/16/huge-landslide...
| dboreham wrote:
| Smaller 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
| pixl97 wrote:
| I 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)
|
| >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.
| sjkoelle wrote:
| the huascaran landslide too
| yard2010 wrote:
| Some people like the idea of looking into the future, but I
| would prefer going back in time as a passenger only to see.. I
| mean we're time traveling any instant, just wait enough and you
| get to time travel, but there are some events like 100-200
| years ago you can't ever really experience..
| jononomo wrote:
| Apparently there are records of a loud noise being heard as far
| away as Timbuktu in the 12th century.
| dylan604 wrote:
| > only to find out I'm eight hundred years too late.
|
| and I thought I was bad for missing the timezone and being an
| hour late to watch the ESA's Euclid launch. Besides, I was able
| to watch mine in replay.
| jmclnx wrote:
| > 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
|
| Seems that ended in 1250, coincidence ??
| [deleted]
| gumby wrote:
| > ... 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 wrote:
| The lengths people will go to to avoid using the metric
| system!
| dylan604 wrote:
| They 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.
| gumby wrote:
| 93 million miles you mean
| dylan604 wrote:
| No, I mean 3 million Olympic size swimming pools, you "do
| anything to avoid metric system" person
| gumby wrote:
| OK then about eight light minutes. Not sure there is any
| 31 mile long olympic swimming pool, though, but there are
| plenty of units out there so I can admit the possibility.
| vkou wrote:
| I think most people can understand what a meter is, or what
| a kilometer is, but would have no idea of what a kilojoule
| is, or what the energy inside a barrel of oil is.
| buu709 wrote:
| I'm Canadian, and have never traveled to Europe but,
| every imported piece of food I've ever seen has the
| energy measured in kilojoules.
| ReptileMan wrote:
| Actually it is both in kj and ccal
| gumby wrote:
| I think the Tsar Bomba was designed metric (unlike the
| contemporary US bombs and space program) so perhaps it was
| chosen for that reason?
| hansvm wrote:
| Funny how we went through the monumental effort to build
| and adopt a whole new system of units just because a few
| people were bad at grade-school arithmetic and mental math.
| gumby wrote:
| It's especially weird because 12 is so much more useful
| than 10.
| olddustytrail wrote:
| Oddly enough, it's still possible to have 12 metres or 12
| tonnes within the metric system. I realise this is
| baffling and confusing to Americans but it's really true!
| yk wrote:
| double-decker buses are clearly imperial units.
| mcdonje wrote:
| >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.
| swader999 wrote:
| Article didn't mention it but lightning is a significant force in
| mountain erosion too.
| PNewling wrote:
| I don't think I have ever heard of this, have any more details?
| trillic wrote:
| There'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 wrote:
| https://www.nationalgeographic.com/science/article/140105-li.
| ..
|
| 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 wrote:
| Unless their definition of "significant" is my definition of
| insignificant, it's not true.
| EdwardDiego wrote:
| I'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.
| mjb wrote:
| For comparison, this is between 4 and 5 times larger than the
| 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
| masklinn wrote:
| > 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.
|
| I can't fathom how we could think that, surely as long as
| plates move around and stone weathers this sort of geological
| events can happen?
|
| They're certainly not common on historical timescales, so the
| odds you'd find yourself sharing time (let alone space) with
| one are low, but what would have made them _stop_?
| marssaxman wrote:
| Geology went hard for uniformitarianism during the 19th
| century as a reaction against the earlier "catastrophist"
| worldview, which had interpreted all major land forms as
| consequences of the great global flood described in the Bible
| (or something like it). This yielded a strong preference for
| theories involving continuous processes operating over long
| spans of time, and skepticism of theories involving sudden,
| violent changes. This swung back to a better balance during
| the 20th century; with the ghost of Noah's Ark exorcised, the
| role of local "catastrophes" in geologic history could again
| be taken seriously.
| bombcar wrote:
| Wasn't there some massive icedam caused lake that was the
| size of basically the entire Pacific Northwest and it
| flooded out in a matter of years? And nobody believed that
| could happen.
| matt_morgan wrote:
| Right, figuring that out was an important step in our
| appreciation that catastrophes happen and are impactful
| on a large scale, you know, not just little things that
| get covered up by longer-term, consistent processes.
|
| https://en.wikipedia.org/wiki/Glacial_Lake_Missoula
|
| It's why western Washington state is all
| https://en.wikipedia.org/wiki/Channeled_scablands
| mjb wrote:
| Plate techtonics was very new (and rather controversial, as I
| understand it), science in the late 1960s: https://en.wikiped
| ia.org/wiki/Plate_tectonics#History_of_the...
| WalterBright wrote:
| My grandfather (a vulcanologist) set up measuring stations
| in Iceland in the 1930s to prove that Iceland was spreading
| apart. Unfortunately, the war interrupted that, and he died
| in the war.
| pyinstallwoes wrote:
| Any more insights into his research and measurements that
| you know of? Thanks for sharing.
| WalterBright wrote:
| https://de.wikipedia.org/wiki/Ferdinand_Bernauer
|
| "His greatest contributions to the academic world - proof
| of Continental Drift through his studies in Iceland and a
| crystal growing method now lost to mankind - attest to
| his considerable intellect and dedication."
|
| https://expo.uw.edu/expo/apply/494/proceedings/show?id=68
| 965
|
| "Geschichtete Lava an islaendischen Vulkanen" von
| Ferdinand Bernauer, Berlin-Charlottenburg
|
| Zietschrift der Deutschen Geologischen Gesellshaft Heft 2
| Band 89 Berlin 1937 / Verlag von Ferdinand Enke in
| Stuttgart
| swamp40 wrote:
| They would mostly stop because now the Earth is nicely round.
| Most of the original bumpiness created during Earth's
| creation has been smoothed out. That's probably what he
| meant.
| qup wrote:
| I've heard that the earth, if scaled down to the size of a
| pool/billiards ball, would be smoother than the ball.
|
| I often use that to explain how spinning cue balls can
| manage to change the angle of the shot, given the same
| impact point as a non-spinning cue ball, in an effect pool
| players call "throw." [1]
|
| The peaks and valleys of the pool ball will reliably grip
| like gears. Sometimes the balls even stick together
| momentarily before they release, changing the outcome of
| the shot, in another effect called "skid". [2]
|
| Also the referenced site is an amazing deep-dive into a
| niche topic, worth a glance--especially the high speed
| videos demonstrating the physics of the game.
|
| [1] https://billiards.colostate.edu/tutorial/throw/ [2] htt
| ps://billiards.colostate.edu/resource_files/onoda_skid_ar..
| .
| poulsbohemian wrote:
| >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.
|
| I grew up in this area... there are two tragedies that most
| people living in this area don't realize. One, before the war a
| good chunk of the region was populated by people of Japanese
| origin who farmed and never got their farms back after the war,
| and two, it is some of the richest farmland in the world - now
| covered with concrete tilt-up warehouses, highways, etc.
| Humanity is interesting.
| a_t48 wrote:
| Also grew up there. The soil was _very_ rich.
| farnsworth wrote:
| Wild to think about the fact that there were people living
| there who would have seen (or been buried) by that. Same with
| some of the cataclysmic floods and other events that came with
| the end of the last ice age.
| ftxbro wrote:
| > "Back-of-envelope, that Osceola event released about 10^19
| Joules of energy*. The scale of these things is absolutely
| incredible."
|
| I wonder can we put a kind of "earth turbine" to capture some
| of that energy? Maybe tap it somehow to not release all in one
| catastrophe and make it safer at the same time.
| mjb wrote:
| Related, 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).
| sjkoelle wrote:
| its a real geologic zoo around there
| geostupid wrote:
| Love the geologic zoo!
|
| I refer to botanical gardens as 'botanical zoos' as well
| User23 wrote:
| I believe zoo is short for "zoological garden," but of
| course it's taken on additional meanings. Still, one
| occasionally hears the term "zoological and botanical
| garden."
| mjb wrote:
| It really is a zoo (and the whole of Western Washington is
| generally). If you're interested in the topic, I really
| enjoyed https://www.amazon.com/Roadside-Geology-Washington-
| Marli-Mil...
| kabdib wrote:
| My 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.
| JamesLeonis wrote:
| > 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
| Jun8 wrote:
| I 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.
| fractallyte wrote:
| I 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
|
| 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/
| bradrn wrote:
| Paper: https://doi.org/10.1038/s41586-023-06040-5
| mint2 wrote:
| An ancestral mount Shasta in California collapsed sending a
| debris flow 28 miles covering something like 675sq km
| davely wrote:
| Speaking 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...
| placesalt wrote:
| Non-paywalled article:
|
| https://arstechnica.com/science/2023/07/massive-peak-collaps...
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