Greetings Squaddies! Welcome back. This week's question comes from the venerable Keg O' War. He asks:
Just how deep is the ocean and how deep have we been able to explore?The simply answer is that it's tremendously fucking deep. The numerical answer is that the deepest point of the ocean is in the Mariana Trench, 210 miles SW of Guam. There, the ocean reaches a depth of 36,201 feet. This is actually the answer to both questions, as this depth was reached by a manned submersible in 1960. To put this depth in perspective, if you were to put Mount Everest in the Mariana trench, the tip of Everest would still be close to two miles underwater. Coincidentally, this is also the deepest point in the Earth's surface. The Mariana Trench, is your typical trench, long, deep and thin. For all of its depth, it's only 43 miles wide.
Here's something you may not have known, but the average depth of the ocean is deeper than the average height of surface land is high. I had found a stat that showed that, but now, for the life of me, I can't find it. Oh well, I guess you're just going to have to trust me.
Just to give you a picture of what life is like at those depths, well, first of all, it's completely black. Light can't reach those depths, so bring a flashlight. It's also a mite chilly, at 2 - 4 degrees Celsius, which is about35 - 39 degrees Farenheit, not counting the temp by thermal vents, so bring a sweater. You're also going to want to bring some sort of high pressure suit as the pressure there is over 8 tons per square inch. That's 8 tons, as in 16000 lbs. It makes sense, given that there's several miles worth of water above your head, and even if it doesn't, it's a fact, so arguing is kind of silly.
The most amazing thing about the deepest part of the ocean, is that even under those harsh conditions, life still exists. They recently found a form of plankton that lives on the ocean floor at those depths that feeds on pieces of matter that drift down off of dead things from shallower parts of the ocean. So the next time you complain that they got your fries wrong at the drive through, be thankful that you're not eating bits of dead squid that had to drift through 8 miles of ocean to get to you. I'm sure there are plankton mothers telling their plankton kids not to complain about the blackness, cold and high pressure because they don't have to work in a cube all day and fight traffic.
Included in the sources link, I've added some links to some sites that have pictures of the creatures that live at the deeper parts of the ocean. It's amazing to see the level of diversity that exists at those depths. There are some pretty messed up looking fish living down there, but they're getting it done, so more power to them.
Thanks again to Keg for the question. Keep 'em coming.
The Mariana Trench - Oceanography
ExtremeScience.com - Challenger Deep
LiveScience.com - Organisms Found in Deepest Part of Ocean
NOVA Online - Deep-Sea Bestiary
MarineBIO.org - The Deep Sea