Are there natural disasters in the deep ocean?

August 30, 2008 4:59 PM

Are there natural disasters in the deep ocean?

Up here, we've got hurricanes, and earthquakes, and tsunamis, and tornados, and mudslides, and wild fires, and volcanos, and you name it.

And I assume that some of these things have significant effects near the surface of the ocean, or near the ocean floor.

But what about the deep ocean, far from both the surface and the floor? Are there any significant natural disasters of the same scale, striking suddenly and leaving vast swaths of fish with many dead and the rest wondering "what the hell was that"?

To be clear up front, I'm talking about natural disasters, not disasters clearly caused by human activity (such as dead zones due to pollution or strip trawling).

posted by Flunkie to Science & Nature (15 answers total)

There are underwater volcanoes that erupt and sometimes the result is the formation of an island. I would imagine those probably kill some fish in the process...
posted by Nattie at 5:02 PM on August 30, 2008

Response by poster: Well, I think volcanoes count as "near the floor". It's not like a volcano blows and suddenly an island shoots up from out of nowhere; rather, the island has been growing for a long time, as a result of many eruptions, and at some point breaks the surface.

Perhaps undersea volcanoes have significant effects far above themselves, though, due to dispersed gasses and such?
posted by Flunkie at 5:07 PM on August 30, 2008

Underwater landslides and earthquakes are a major cause of tsunamis.
posted by chairface at 5:08 PM on August 30, 2008

Response by poster: Perhaps I shouldn't have said "deep ocean" in the title. I'm talking about the part of the ocean that is nowhere near anything but water.
posted by Flunkie at 5:24 PM on August 30, 2008

How about toxic algal blooms, magnetic field changes and global warming.
posted by acro at 5:24 PM on August 30, 2008

Adding to this, the rise / collapse of deep sea thermal vents, 'black smokers', etc. These might be a bit more up your alley, as there's a few documented cases of these events destroying / forming whole new ecosystems, previously discovered isolated species disappearing, etc.

(If you get into the biology around such things, it's fascinating. Species which are totally dependant across their whole life cycle (as far as an be told from cursory examination) upon, for example, black smokers, being wiped out when one collapses/stops smoking - only to be found again at another newly formed but isolated vent a long way away. How did they get there? A ruggedised egg/larval stage that travelled? Are they a dimorphic adaptation of a more common species, and so can 'spontaneously' re-appear in that form where conditions are suitable? Convergent evolution? Nobody knows for sure...)

Short answer: Nature is everywhere, so 'natural disasters' are everywhere too. Comet Shoemaker-Levy hitting Jupiter was just as much a 'natural disaster' as Katrina or the Boxing Day tsunami; it's just that we stood around saying "isn't that fascinating?" rather than going "Arrrrgh!" and running away...
posted by Pinback at 5:40 PM on August 30, 2008 [4 favorites]

Volcanoes/vents would also change the dissolved chemical composition and pH of the water column above them, as toxic gases escape. I suppose surprise currents, formed from unusual weather or far-off landslides, could also pass through mid-deep water and alter the temperature/salinity/pH/dissolved oxygen of the domestic water enough to threaten sea life.
posted by cowbellemoo at 6:13 PM on August 30, 2008

One of the possible explanation for the Bermuda Triangle phenomenon is collapsing sea bed natural gas pockets. Upon collapsing vast amounts of water rush into fill the pocket as the gas rises up to the surface.

If I was a fish I'd certainly be all whiskey tango foxtrot man. And then I would make an underwater fart joke.
posted by wavering at 6:40 PM on August 30, 2008

Well, the amount of oxygen in water is a critical factor for sea life. One might expect to see the most life in warmer waters; but in fact it's the cooler waters that hold enough oxygen necessary for larger and more varied animals. A raise in temperature means suffocation for many marine animals. But that is a slower disaster, like a famine.

The sea also has plagues of simple animals, like on land--jellyfish, so called cockroaches of the sea, are thriving on the turmoil of the modern ocean, and crowding out or eating up the food of more complex life.

I donno if these are the disasters you're thinking of, but they're still disasters for the most complex forms of marine life.
posted by Citizen Premier at 6:58 PM on August 30, 2008

One of the world's most important finds in paleontology is the Burgess Shale in Canada. It is thought that this unique area was created by an undersea landslide that happened millions and millions of years ago.
posted by Cool Papa Bell at 9:23 PM on August 30, 2008

Actually, I should say, a entire series of undersea landslides.
posted by Cool Papa Bell at 9:25 PM on August 30, 2008

It's true though that in the middle of ocean, vertically speaking, you're pretty much shielded from disasters by the body of water. It's like being in an underground bunker with 3 mile thick walls. The only problem is that there's no food there, either, fish mostly feeds on plankton that needs light. You can be pretty safe there if you stock up on energy and food.
posted by rainy at 9:35 PM on August 30, 2008

This is sitting off Sydney at the moment - might lead you down a relevant path.
posted by strawberryviagra at 5:00 AM on August 31, 2008

YES! There are regions of the deep sea that experience deep-sea storms. These are strong currents that stir up the bottom and can occur anywhere in the deep-sea. But all the other ones already mentioned are probably the most devastating to life in the deep-sea. Food is already scarce and animals are living on the edge of extremes with temperature -- any changes can drastically alter the ecosystem. Volcanoes on the seafloor, earthquakes and landslides are primary causes of this.

It is important to also note that the influence of man is also felt in the deep-sea. DDT has been found at depths >3000m and deep-sea submersibles (manned and unmanned) frequently report on trash on the seafloor.

I will also mention dead-zones (most closer to land) and methane release (on geologic timescales), although they do not fit the question exactly.
posted by rvrlvr at 2:09 PM on August 31, 2008

Methane hydrates -- solidified methane at/under the ocean floor. There has been some study of the possibility that these can suddenly sublimate back into a gas in large quantities. This would produce enormous clouds of bubbles, and those bubbles would drastically alter the local density of the ocean. So you're a fish in the middle of the ocean, and the giant cloud of bubbles rises up toward you and your buddies, and suddenly you're not buoyant anymore.
posted by madmethods at 12:14 PM on September 1, 2008 [1 favorite]