4 ms·

Galapagos Islands: Erosion fells Darwin’s Arch

62 points by janpot 5y ago

yread 5y ago
Aw man! First Azure Window on Malta now this one!
rob74 5y ago
Sad, but that's the way of the world... Honestly, I visited Galápagos in 2019 and wasn't even aware this arch existed. Might be due to the fact that Darwin & Wolf Islands are two of the smallest islands in the archipelago and located ~ 100 km away from the rest. Plus, they are interesting mostly only for divers, while the other islands offer more varied attractions (turtles, penguins, other endemic flora & fauna, volcanoes, snorkeling, ...).
tomhoward 5y ago
Nature running its course. I live in the same state as The Twelve Apostles [1], a famous group of limestone stacks on the coast of Victoria, Australia, south-west of Melbourne. Just up the road, there is a formation that was called London Bridge - a limestone formation protruding out from the land, with two stacks, making it a double-span bridge. Then one day in 1990, the bridge section adjoining the land collapsed. Two sightseers were on it at the time, though mercifully not on the part that collapsed; they were rescued by helicopter after a few hours. It just so happened that this collapse occurred during the high school year when we were studying limestone cliff formations in geography class. I remember our teacher impressing upon us that it was a geologically regular and normal occurrence, but infrequent in human life terms, so we were lucky to be able to observe the event just at the time we were studying the phenomenon. Since then they've called it London Arch [2]. [1] https://explorethegreatoceanroad.com.au/the-twelve-apostles-in-australia/ https://explorethegreatoceanroad.com.au/the-twelve-apostles-... [2] https://en.wikipedia.org/wiki/London_Arch https://en.wikipedia.org/wiki/London_Arch
- daveslash 5y ago
  Reminds me of the 2008 collapse of Wall Arch in Arches Nat'l Park, Utah. https://en.wikipedia.org/wiki/Wall_Arch https://en.wikipedia.org/wiki/Wall_Arch. Just a few days before it's collapse, I was climbing on it; well, I couldn't quite get to the Arch part (so I know it's collapse wasn't my fault), but I can't help but think: if it was on the verge of collapse, would it have been able to hold a couple of 150lb monkeys jumping around on it (my buddy and me)?
  - mc32 5y ago
    I think wind forces are probably over 300lbs though perhaps different vectors. But who knows maybe you could have been the straw that would have broken the camel’s back.
arbuge 5y ago
Brings this to mind from 4 years ago: https://en.wikipedia.org/wiki/Azure_Window https://en.wikipedia.org/wiki/Azure_Window https://timesofmalta.com/articles/view/the-azure-window-lost-and-gone-forever.641810 https://timesofmalta.com/articles/view/the-azure-window-lost...
- automatic6131 5y ago
  The azure window has gone!! I didn't know that. It's such a shame, because I dived it twice in my life in 2008 and 2010. Gozo does indeed have many other good diving spots.
mrtnmcc 5y ago
Are we seeing the formation of new arches at a similar rate? It seems we must.
- rob74 5y ago
  Good question! I guess most "new" arches start out as small and relatively unspectacular "windows", then grow over thousands or millions of years and finally collapse. So when a new arch forms, it doesn't turn into a tourist attraction right away. The place with probably the highest density of arches in the world, Arches National Park, doesn't even seem to be sure how many arches it has. Their homepage says "over 2000", while the article https://www.nps.gov/parkhistory/online_books/geology/publications/bul/1393/sec8.htm https://www.nps.gov/parkhistory/online_books/geology/publica... has a much more conservative estimate of 124...
- WarOnPrivacy 5y ago
  Arches seem to be notable because they are the shortest part of the erosion process - but still last years. My take: A quickening erosion cycle could see an accelerated creation of arches, providing the cycle hasn't been altered eg: more top-down erosion. It could be that an accelerated process is still happening too slow to see new arches. It may also be that climate change isn't strongly manifesting itself this way.
  - lmilcin 5y ago
    > My take: A quickening erosion cycle could see an accelerated creation of arches I think increased erosion would also cause arches to fail faster (run through its lifetime at increased speed). I think there is no limit to how fast an arch can erode (ie. the erosion can easily speed up orders of magnitude) but at the same time I don't think we could be seeing orders of magnitude more arches created, which would be necessary to maintain the number of arches that are now going through their lifecycle faster. This lets me believe that overall increased erosion would cause less arches to be present at any point in time. This is just a thought experiment, I have no data to back it up.
limaoscarjuliet 5y ago
I'm wondering if humans are helping the destruction. Warmer, more acidic ocean; more waves; more storms...

62 points by janpot 5y ago

Aw man! First Azure Window on Malta now this one!

Sad, but that's the way of the world... Honestly, I visited Galápagos in 2019 and wasn't even aware this arch existed. Might be due to the fact that Darwin & Wolf Islands are two of the smallest islands in the archipelago and located ~ 100 km away from the rest. Plus, they are interesting mostly only for divers, while the other islands offer more varied attractions (turtles, penguins, other endemic flora & fauna, volcanoes, snorkeling, ...).

tomhoward 5y ago

Nature running its course. I live in the same state as The Twelve Apostles [1], a famous group of limestone stacks on the coast of Victoria, Australia, south-west of Melbourne. Just up the road, there is a formation that was called London Bridge - a limestone formation protruding out from the land, with two stacks, making it a double-span bridge. Then one day in 1990, the bridge section adjoining the land collapsed. Two sightseers were on it at the time, though mercifully not on the part that collapsed; they were rescued by helicopter after a few hours. It just so happened that this collapse occurred during the high school year when we were studying limestone cliff formations in geography class. I remember our teacher impressing upon us that it was a geologically regular and normal occurrence, but infrequent in human life terms, so we were lucky to be able to observe the event just at the time we were studying the phenomenon. Since then they've called it London Arch [2]. [1] https://explorethegreatoceanroad.com.au/the-twelve-apostles-in-australia/ https://explorethegreatoceanroad.com.au/the-twelve-apostles-... [2] https://en.wikipedia.org/wiki/London_Arch https://en.wikipedia.org/wiki/London_Arch

daveslash 5y ago
Reminds me of the 2008 collapse of Wall Arch in Arches Nat'l Park, Utah. https://en.wikipedia.org/wiki/Wall_Arch https://en.wikipedia.org/wiki/Wall_Arch. Just a few days before it's collapse, I was climbing on it; well, I couldn't quite get to the Arch part (so I know it's collapse wasn't my fault), but I can't help but think: if it was on the verge of collapse, would it have been able to hold a couple of 150lb monkeys jumping around on it (my buddy and me)?
- mc32 5y ago
  I think wind forces are probably over 300lbs though perhaps different vectors. But who knows maybe you could have been the straw that would have broken the camel’s back.

arbuge 5y ago

Brings this to mind from 4 years ago: https://en.wikipedia.org/wiki/Azure_Window https://en.wikipedia.org/wiki/Azure_Window https://timesofmalta.com/articles/view/the-azure-window-lost-and-gone-forever.641810 https://timesofmalta.com/articles/view/the-azure-window-lost...

automatic6131 5y ago
The azure window has gone!! I didn't know that. It's such a shame, because I dived it twice in my life in 2008 and 2010. Gozo does indeed have many other good diving spots.

mrtnmcc 5y ago

Are we seeing the formation of new arches at a similar rate? It seems we must.

rob74 5y ago
Good question! I guess most "new" arches start out as small and relatively unspectacular "windows", then grow over thousands or millions of years and finally collapse. So when a new arch forms, it doesn't turn into a tourist attraction right away. The place with probably the highest density of arches in the world, Arches National Park, doesn't even seem to be sure how many arches it has. Their homepage says "over 2000", while the article https://www.nps.gov/parkhistory/online_books/geology/publications/bul/1393/sec8.htm https://www.nps.gov/parkhistory/online_books/geology/publica... has a much more conservative estimate of 124...
WarOnPrivacy 5y ago
Arches seem to be notable because they are the shortest part of the erosion process - but still last years. My take: A quickening erosion cycle could see an accelerated creation of arches, providing the cycle hasn't been altered eg: more top-down erosion. It could be that an accelerated process is still happening too slow to see new arches. It may also be that climate change isn't strongly manifesting itself this way.
- lmilcin 5y ago
  > My take: A quickening erosion cycle could see an accelerated creation of arches I think increased erosion would also cause arches to fail faster (run through its lifetime at increased speed). I think there is no limit to how fast an arch can erode (ie. the erosion can easily speed up orders of magnitude) but at the same time I don't think we could be seeing orders of magnitude more arches created, which would be necessary to maintain the number of arches that are now going through their lifecycle faster. This lets me believe that overall increased erosion would cause less arches to be present at any point in time. This is just a thought experiment, I have no data to back it up.

limaoscarjuliet 5y ago

I'm wondering if humans are helping the destruction. Warmer, more acidic ocean; more waves; more storms...