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New Sub Dives To Crushing Depths
University of Washington Scientists are reporting that they have a new autonomous underwater vehicle that increases both the attainable depth and duration of deployment over current submersibles. Weighing in at just under 140 pounds, the "Deepglider" is able to stay out to sea for up to a year and hit depths of almost 9,000 feet. "Deepglider opens up new research possibilities for oceanographers studying global climate change. The glider's first trip revealed unexpected warming of water near the ocean floor, and scientists are interested in studying whether the temperatures are related to global warming."
For those who don't speak ancient google translated it to be:
9 000 feet = 2 743.2 meters
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Go canucks, habs, and sens!
I'd like to test the effects of global warming on the production and recreational use of the marijuana plant. I swear to God it will be a scientific study.
Dedicated Cthulhu Cultist since 4523 BC.
The average heat flux from the earth is less than 0.1W/m2. Compare that to ~ 1000 W/m2 for the sun. Sure, it varies all over the place (see: volcanoes, etc.), but it's not a no-brainer where any heat anomalies the glider detected came from. In general, the deep ocean is quite cold because of that whole thermal expansion thing (also note that seawater is densest a few degrees above freezing (~4 deg C, if I recall). So heating from the bottom tends to cause convection.
You'll note that the scientists quoted don't mention global warming; they are excited to see stuff that they didn't expect. That's good enough to satisfy their intellectual curiosity & need to come up with new and interesting grant proposals.
You'll also notice that scientists in general don't sell newspapers or magazines. It's the journalists whose job it is to butcher the science to sell newspapers and magazines.
Finally, the oceans are very much tied up in our little carbon experiment. A good bit of any extra heat that is trapped in the atmosphere will go into the oceans. Also, a lot of the CO2 that we've emitted is already going into the oceans, which leads to ocean acidification. This is the rate of carbonic acid input (that's CO2 + H2O H2CO3 H+ + HCO3-) is much higher than the ocean can buffer it with CaCO3 (which buffers effectively, but only on very long time scales). In the meantime, hope you don't like coral.
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I'm working in a buoyancy related problem so I have to point this out. From the full article: "When pressure compresses a hull in a traditional glider, it gains buoyancy and requires more energy to control." If it's compressed, the volume shrinks, it gains density and loses buoyancy.
That is probably the very question they're trying to answer.
Ocean water is not stagnant and there are currents that mix surface water with warmer water in places where the surface water is colder (and denser) than the deeper water.
The reason this matters, from TFA, is that this is a glider, not a submarine. It's cheaper, lighter, and more energy efficient than dropping a big ball to the bottom of the ocean. This thing can drive around and look at stuff very similarly to how a non-crush depth submersible could do.
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The oceans are indeed a mystery. We haven't studied them near as well as we have the land above, mainly becuase we humans are quite puny in comparison, and absolutely must have a ready supply of breathable air. Preferably at an ambient pressure of less than 100psi.
The deepest we've ever been, and two guys lived through it, is actually deeper than Everest is tall, 37,800 feet to the bottom of the Marianas Trench off the Phillipines. The iron ball, 6 feet in diameter that they were in, suspended from the kerosene ballast tanks of the Navy's Trieste, was squeezed by the nominally 18kpsi pressure, enough to warp the frames of the equipment braces holding the controls and monitors for the tv cameras that I actually helped build back in about 1960. The Treiste ran everything in it and on it from big racks of Sears Die-Hard batteries, each of which had a heavy balloon with half a pint or so of battery acid in them, snapped over the neck of the cell, with a wire cage to keep them from being dislodged by water currents. They brought back a lot of pix of blind, eyeless fish from down there, and they turned the cameras around to look at the batteries once and found that all of the balloons had been driven into the batteries. So don't ever let anybody tell you that water is incompressible, it is at 18,000 psi. So is oil, we had filled the pan & tilt drives with motor oil, and layed a neoprene rubber gasket on the top, then drilled some holes in the cover to let the pressure in. There was about an inch of clearance to the closest gear. One gasket was cut thru, the other was damaged by the turning gears slicing into it but held.
But the guys weren't in very good shape by the time it had surfaced and the gondola opened to let/get them out, so thats a trip they never repeated, and they were using state of the art air recycling gear. If something better has been invented now for that, I'm not aware of it. The danger of it imploding was very real, this was about 2x deeper than Alvin or its successor ilk have ever been. But then Alvin and company have access holes that can be opened, this ball didn't due to the pressure calcs saying they couldn't support it, so it was cut in half, and the seams epoxied together after the guys were inside, and it had to be removed somehow to get them back out. The Navy never said how they opened it once the epoxy was set.
But, man being the curious thing that he is, if better tools can be made, I expect there will be ready volunteers to occupy the viewports for yet another trip into that abyss.
Do you feel lucky? I think I'l stay up here, thank you...
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Cheers, gene