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A hypercane is a hypothetical class of extreme tropical cyclone (wikipedia.org)
61 points by bane on Sept 11, 2017 | hide | past | favorite | 18 comments

Hypercanes are thought to have played a role in the biggest mass extinction ever, the end-Permian.[1] Back then all the continents had converged into the massive Pangea supercontinent, which was surrounded by an equally massive global ocean. Bear in mind that today's most intense tropical cyclones are the ones in the Pacific, the world's largest ocean. Back during the Permian, the global super ocean would've been an even richer feeding ground for cyclones.

From the article cited below, "there might have turbocharged 'hypercanes' of almost unbelievable intensity assaulting the supercontinent Pangaea—the result of runaway global warming." Also bear in mind that the supercontinent Pangea was assumed to be habitable almost exclusively along its coasts, with an immense desert covering most of its non-coastal land. So if life was mostly concentrated along the coasts and the coasts are constantly getting slammed by hypercanes... yeah, not good.

Certainly lots of things contributed to the Permian extinction. Some have referred to it as the "Murder on the Orient Express" extinction: everything caused it. Pangea, an asteroid impact or two, volcanoes, methane releases from the ocean floor, maybe even a gamma ray burst hit the Earth too. The sheer scale of death seems to imply multiple causes. But regardless of what the primary causes were, the hypercanes part of it always fascinated me.

[1] https://www.theatlantic.com/science/archive/2017/07/a-road-t...

I thought supermonsoon was much more likely.

Hyercane sounds like sci fi.


... As the area of sub-700mb atmospheric pressure slid over the Tetons and down into the Yellowstone Caldera, an enormous weight was lifted. Like a curious bear pushing aside the stone on the lid of a bottomless box swarming with a quadrillion angry bees, a trillion tons of ash exploded into the stratosphere. Within hours, half of humanity lay sprawled under a smothering blanket of doom ...

If any of the events required for this incredibly speculative thing to happen occurred we'd probably have bigger things to worry about.

I hypothesize that hypertornados would go along with it, and since we're speculating about things that could be triggered by large asteroid impacts, I imagine there will be hyperquakes, too. We could call the long, cold period after hyperwinter.

This link is stupid.

The link is pretty bizarre to me. It can only occur if an enormous region of an ocean is tremendously heated. Short of a Chicxulub-style event in which down falling ejecta massively heats a large region, I don't see how you get there.

Even then, the link requires that the troposphere remains at a relatively normal temperature, which rules out ejecta heating. I just don't see a mechanism.

That would be especially nasty. Even if you survive the winds and don't drown in the storm surge, there would be a threat that ordinary hurricanes do not pose: burns.

The ocean temperature necessary to support a hypercane is high enough to cause third degree burns in around 10 minutes and second degree burns in around 20 minutes.

"The ocean temperature necessary to support a hypercane is high enough to cause third degree burns in around 10 minutes and second degree burns in around 20 minutes."

I think you got those mixed around :-)

I think you misread 120 degrees Fahrenheit as 120 degrees centigrade.

Nope, 120F is just under 50C, which is plenty hot. A blissfully hot scalding shower is 110F/43C, and most people can't take a hot tub/spa temperature of more than about 104F/40C.

Anything greater than 98.6F/37C will cause body temperature to rise, and you can't expect to cool off by sweating when the neighborhood is underwater.

US Consumer Products Safety Commission recommends 120F as maximum household hot water temperature, and says 5 minutes exposure can cause 3rd degree burns - https://www.cpsc.gov/s3fs-public/5098.pdf

Water at 120C would not be an ocean, it would be steam.

120 degrees Fahrenheit is pretty hot-that’s around the temperature of water in a water heater, and those have plenty of warning labels on them.

Curious if a thermonuclear explosion in the sea could kick off something like this. Y'know, because nukes aren't scary enough as they are. How long would the sea temperature need to be at 50C for, and what volume of water? And presumably if you're dropping an h bomb in the sea there's going to be a tsunami as well.

So the thermonuclear devices detonated near the sea surface were in the ballpark of 10Mt. At least half of the yield (probably more due to reflection) went up into the atmosphere. I'm curious if a more powerful weapon (Russia's Tsar Bomba had a yield of 50Mt, with a theoretical limit of 100Mt), detonated below the sea (so that all/most of the energy heats up water) could achieve a hypercane, or if it's just a drop in the water (pun intended)

Hypercanes would be pretty intense; wind speeds of 500 mph would destroy most buildings, and almost all skyscrapers (which are not built to withstand such lateral loads).

Almost all skyscrapers? Are there skyscrapers out there that wouldn't be leveled by a 500mph wind!?

300 mph tornados tear up everything except some roadways, foundations and deeply-driven steel pilings. 500 mph would just make a messier mess. If that were multiplied over continental size, that would definitely extinct some species.

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