Reply #29: Cumbre Vieja has been way over-hyped

[Dogmudgeon]

I dispute that the tsunami will be as high as the Day study indicates. Even Day and company hedged their bets.

First, Cumbre Vieja is not in as bad a state as it is said to be. The island is not on the verge of collapse. Yes, it's approaching a state where a massive landslide will be inevitable, but it's not immanent. The day of reckoning is not likely to happen any time soon. And a series of smaller, controlled landslides have been discussed.

Second, I think they've overestimated the intensity of the landslide. The model for the run was the Lituya Bay landslide in 1958, which was a very sharp drop, sharper than Cumbre Vieja. And the basin of Lituya Bay amplified the tsunami, while the wide-open Atlantic would tend to damp it.

No doubt about it, there is a real risk, but I think it's been hyped.

Now, when you talk about geological threats, I am more concerned about the Yellowstone supervolcano. It has been increasing in activity since around 1990, and the overall trend has been toward more and more activity. An eruption of Yellowstone would produce over 2000 times as much impact as Mount Pinatubo did. Pinatubo depressed global temperatures by about a degree; a supervolcano eruption would subject us to a several-year-long volcanic winter. Much of the northern hemisphere would be covered by dirty ice and snow for five, ten years or more. Agriculture world wide would simply stop for a decade. The effects of a climate flip-flop or a post-Peak-Oil economic crisis would be small peanuts compared to a supervolcano eruption.

The good news is that it may take another thousand years for this to happen. The bad news is that, then again, it may take another six months for this to happen.

--p!