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As a side tangent, Oregon is a part of the world where volcanoes do just sort of spring up practically overnight, geologically speaking. Mt Bachelor was formed

by elihu 5y ago

As a side tangent, Oregon is a part of the world where volcanoes do just sort of spring up practically overnight, geologically speaking. Mt Bachelor was formed between 18,000 and 8,000 years ago, according to wikipedia. They can also disappear literally overnight. Mt Mazama erupted about 7,700 years ago and is now Crater lake. There were a lot of eruptions around Newberry caldera around that same time, and there've been eruptions as recently as about 1,300 years ago.

angelzen 5y ago
There is also Mt St Helens, short distance across the Columbia, which largely disappeared in 1980.
- irrational 5y ago
  It didn’t disappear, it’s still there. It’s just scattered over a much larger area ;-)
- elihu 5y ago
  Good point. Also worth noting that that was comparatively mild; according to Wikipedia, St. Helens ejected a little more than a cubic mile of material, whereas Mt. Mazama is estimated to have ejected about 27 cubic miles of material. It's hard to imagine that kind of explosion. Mt. Mazama seems to have been a bit of an outlier, though: > The United States Geological Survey has referred to the 7,700 years ago Mazama eruption as the largest explosive eruption within the Cascades in the past million years, and one of the largest eruptions during the Holocene epoch. Seems kind of improbable that the biggest anything happened in the most recent 0.77% of the observed time interval, which makes me wonder if there may have been others we just don't know about. Improbable events do happen though, so maybe it's just dumb luck (if we want to call it that) that we had such an event within relatively recent history.
  - dragonwriter 5y ago
    > Seems kind of improbable that the biggest anything happened in the most recent 0.77% of the observed time interval, The biggest has to happen sometime, and whenever it does will be an improbable time for it to have occurred if the probability is uniform and the resolution of time tracked is high relative to the total interval.
Smoosh 5y ago
If you are interested in the geology of the region, can I recommend to you the videos by Nick Zentner: https://www.nickzentner.com/pbs-nick-on-the-rocks-1/ https://www.nickzentner.com/pbs-nick-on-the-rocks-1/ Also with videos on Youtube in his own channel and in the Central Washington University channel.

by elihu 5y ago

angelzen 5y ago

There is also Mt St Helens, short distance across the Columbia, which largely disappeared in 1980.

irrational 5y ago
It didn’t disappear, it’s still there. It’s just scattered over a much larger area ;-)
elihu 5y ago
Good point. Also worth noting that that was comparatively mild; according to Wikipedia, St. Helens ejected a little more than a cubic mile of material, whereas Mt. Mazama is estimated to have ejected about 27 cubic miles of material. It's hard to imagine that kind of explosion. Mt. Mazama seems to have been a bit of an outlier, though: > The United States Geological Survey has referred to the 7,700 years ago Mazama eruption as the largest explosive eruption within the Cascades in the past million years, and one of the largest eruptions during the Holocene epoch. Seems kind of improbable that the biggest anything happened in the most recent 0.77% of the observed time interval, which makes me wonder if there may have been others we just don't know about. Improbable events do happen though, so maybe it's just dumb luck (if we want to call it that) that we had such an event within relatively recent history.
- dragonwriter 5y ago
  > Seems kind of improbable that the biggest anything happened in the most recent 0.77% of the observed time interval, The biggest has to happen sometime, and whenever it does will be an improbable time for it to have occurred if the probability is uniform and the resolution of time tracked is high relative to the total interval.

Smoosh 5y ago

If you are interested in the geology of the region, can I recommend to you the videos by Nick Zentner: https://www.nickzentner.com/pbs-nick-on-the-rocks-1/ https://www.nickzentner.com/pbs-nick-on-the-rocks-1/ Also with videos on Youtube in his own channel and in the Central Washington University channel.