re: Undersea volcanic eruption in Tonga - tsunami hits - US West Coast warned

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Lots of fish vaporized

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f we had good enough radar, we'd probably see actual rotation couplets withing the giant plume.

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So I'm going to ask an incredibly dumb question. I'm going to be the dumb question of the day guy today. If a major hurricane was going right over the same exact area that this underwater volcano erupted and spewed Ash into the air, how much of a difference would it make in the intensity of this hurricane?

It seems like it could have a pretty decent impact on one

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This Is What Would Happen If A Volcano Erupted Into The Eye Of A Hurricane

It’s peak hurricane season in the Atlantic right now, and Harvey and Irma have been flooding US states and tearing apart Caribbean Islands to unprecedented degrees. If you’d like a serious discussion on the science behind these – and how they might link to climate change – I suggest you click here and here, but if you’ve decided you have had enough of all the doom and gloom and want some more bonkers science instead, then I bid you welcome, dear reader.

To wit, have you ever wondered what would happen if a volcano erupted during a hurricane. Specially, if it erupted within a hurricane’s eye? I have, and I’ve got some rather strange images to put into your head. I suppose you could say that this post was inspired by an Eminem lyric about a volcano meeting a tornado, but because I’m inclined towards the more apocalyptic, I’ve amped things up a bit.

Let’s assume the volcano is a stratovolcano, and is it’s erupting explosively. You’ve got an eruption column rising up from the vent into the sky, and there are pyroclastic flows rolling down its slopes. Let’s also assume this is a single volcano island, a bit like Mount Erebus on Antarctica’s Ross Island.

Now, the hurricane. Hurricanes, or tropical cyclones if you will, are low pressure monsters. This causes high pressure winds to rush into the center and fill the gap, but thanks to the rotation of the Earth, the Coriolis Effect pulls all these wind currents to the right. This has the overall effect of causing hurricanes in the Northern Hemisphere to spin counter-clockwise, and vice versa in the Southern Hemisphere.

So what would happen if a Category 5 hurricane sat directly over an erupting volcano? Well, it’d make a mess, potentially, but not much of one. The volcanic debris – ash, lava and bombs – would fly up into the extremely low pressure eye. Although warm air rises up through the core of hurricanes, the air there is still relatively cool, at least compared to fresh volcanic debris.

This means that all the lava would rapidly cool into ash and volcanic glass fragments, and will then be sucked up in the rotating winds and be dumped, at speeds of 252 kilometers per hour or above, over an area – if the average hurricane is anything to go by – 563 kilometers, more than the average width of a US state. With exceptions for the most explosive of eruptions, this would spread the ash further than it otherwise would be, but it would be incredibly thinly spread.

The pyroclastic flows and any additional lava flows would also cool far quicker in the wet, windy hurricane setting, and fall out and be deposited into the surrounding environment far more speedily. If you’re not quick on your feet and you’re on the slopes of this volcano, this means you might have less time to get away from collapsing, superheated pyroclastic flows, but more time to run away from the normally slow-moving lava. Swings and roundabouts.

As a bonus, you’d get plenty of volcanic lightning in the eye of the storm, making for quite the dramatic image. Volcanic lightning is thought to form when the churning lava and ash builds up powerful electrostatic charges, and thus an electrical imbalance, within the air column. Ice crystals higher up in the eruption column are also thought to play a role.

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