6 ms·

For 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/Osceo

by mjb 3y ago

For 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 ago
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 3y ago
  its a real geologic zoo around there
  - geostupid 3y ago
    Love the geologic zoo! I refer to botanical gardens as 'botanical zoos' as well
    - User23 3y ago
      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 3y ago
    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-Miller/dp/0878426779/ https://www.amazon.com/Roadside-Geology-Washington-Marli-Mil...
farnsworth 3y ago
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.
masklinn 3y ago
> 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?
- swamp40 3y ago
  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 3y ago
    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/ https://billiards.colostate.edu/tutorial/throw/ [2] https://billiards.colostate.edu/resource_files/onoda_skid_article.pdf https://billiards.colostate.edu/resource_files/onoda_skid_ar...
    - vba616 3y ago
      "No, Earth is not as smooth as a billiard ball! ... The billiard-ball-sized Earth’s smoothness would be equivalent to that of 320-grit sandpaper." https://ourplnt.com/earth-smooth-billiard-ball/ https://ourplnt.com/earth-smooth-billiard-ball/ A comment on the article, though, says "I’d like to point out that Earth is about 3400 times flatter than a regulation pool table...I love saying it – The Earth is flatter than a pool table!"
poulsbohemian 3y ago
>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 3y ago
  Also grew up there. The soil was _very_ rich.
ftxbro 3y ago
> "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.

by mjb 3y ago

mjb 3y ago

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 3y ago
its a real geologic zoo around there
- geostupid 3y ago
  Love the geologic zoo! I refer to botanical gardens as 'botanical zoos' as well
  - User23 3y ago
    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 3y ago
  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-Miller/dp/0878426779/ https://www.amazon.com/Roadside-Geology-Washington-Marli-Mil...

farnsworth 3y ago

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.

masklinn 3y ago

> 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?

swamp40 3y ago
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 3y ago
  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/ https://billiards.colostate.edu/tutorial/throw/ [2] https://billiards.colostate.edu/resource_files/onoda_skid_article.pdf https://billiards.colostate.edu/resource_files/onoda_skid_ar...
  - vba616 3y ago
    "No, Earth is not as smooth as a billiard ball! ... The billiard-ball-sized Earth’s smoothness would be equivalent to that of 320-grit sandpaper." https://ourplnt.com/earth-smooth-billiard-ball/ https://ourplnt.com/earth-smooth-billiard-ball/ A comment on the article, though, says "I’d like to point out that Earth is about 3400 times flatter than a regulation pool table...I love saying it – The Earth is flatter than a pool table!"

poulsbohemian 3y ago

>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 3y ago
Also grew up there. The soil was _very_ rich.

ftxbro 3y ago

> "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.