The Deep Sea
neal.fun
neal.fun
Yes. It took him 12 minutes to descend to depth... and 15 hours to ascend.
But if you take a look at the wikipedia article for deep diving you'll note there's a record for a "simulated" dive that's much deeper, 701 meters, done in 1992. Simulated how? Why was it never repeated? Well...
https://web.archive.org/web/20180127104927/http://gtuem.prae...
>Hydra 10 was performed in the Comex hydrogen hyperbaric facilities in Marseilles by three professional divers.
>The dive protocol included: 4 weeks of pre-dive period, 2 day of confinement at 10 msw, 13 days of compression to 675 msw, 3 days of bottom stage between 650 and 675 msw with an excursion dive at 701 msw, 24 days of decompression with 8 working dives in wet chamber.
How were the accommodations?
>A 35 m^3 cylinderical chamber (internal diameter: 2.3 m - length: 9.35 m) with living area and sleeping quarters and sanitaires.
Cozy. Spending 42 days in a steel can pooping a foot away from two new best friends must have been interesting. Did they have fun, at least?
>At 650 msw (6.6 MPa) and deeper, we particularly observed:
>- An increasing HPNS with: slight tremor, myoclonia, mysmetria which induced psychometric and intellectual performance decrease.
>- A dyskinesia associated to proprioception troubles with muscular weakness.
>- A decrease in appetites which required a change in the divers nutrition.
>- Sleep disturbance with decrease of deep sleep phases.
MagicSeaWeed <https://magicseaweed.com/>?
Ah, Metre Sea Water <https://en.wikipedia.org/wiki/Metre_sea_water>.
On 15 November 1976, the research vessel AFB-14 of the Naval Undersea Center (now the Naval Ocean Systems Center), Kaneohe, Hawaii, was conducting oceanographic research in waters about 42 km northeast of Kahuku Point, Oahu, at about 21°51'N and 157°46'W. From 1015 to 1415 Hawaiian Standard Time the ship had de-ployed two large parachutes as sea anchors at a depth of about 165 m in water with a bottom depth of approximately 4600 m.
Edit: Now that I read parts of the source, the only mention of that depth (unless I missed something) is the one I included in my comment. I think that people mistook the depth of the water for the depth at which the shark was caught.
Another part of the source says this (on page 22) :
Apparently, when captured, Megachasma pelagios would have been in the upper depths (165 m) where these euphausiids are commonest at night, and quite possibly might have been feeding on them when it became entangled in the parachute.
The coolest thought this gave me, that I'd never really considered before:
How little life must have changed in the past 3000 years in the deep ocean? Have we even been adjusting the atmosphere for long enough for the circulation currents to take pH changes that deep?
We've essentially remade the surface of the planet, the lower atmosphere, and the top of the ocean. But in the depths... little of this actually impacts them.
From time to time, a single ship dropping down and coming to rest on the bottom. But those are a drop in the bucket compared to the ocean surface area.
Other than that, life is probably very similar to what it was 5,000, 10,000, 100,000, 1,000,000, 10,000,000 years ago. Before modern humans existed, and certainly before industrial civilization. And probably before our species even existed. Mind bogglingly constant.
Plastics. There are plastics down there, mostly fishing nets, that are making huge changes. And whales. There are far fewer whales alive today, and fewer dead whales sinking to the depths, which radically changes the amount of nutrients arriving on the bottom.
I've seen Giant Pacific Octopus diving around 20m, but this visualization lists them at 770m.
Still very cool, and I love how it is searchable in plain text (eg. I can ctrl + f and type octopus and it takes me directly to the correct depth)
https://www.whoi.edu/press-room/news-release/how-do-marine-m...
Similar to free-diving humans, other mammals are much less susceptible to the bends than human scuba divers. Possibly their innate behavior minimizes the risks further — like slowing their ascent as they get close to the surface?
To me, it's more fascinating that land animals like humans can survive at all at ~50x the highest pressure on land. Another fascinating remnant of our oceanic ancestry is the mammalian diving reflex[1].
In contrast, SCUBA divers are usually breathing compressed air while at depth, from their self-contained underwater breathing apparatus.
These divers will have lungs full of gas at several atmospheres of pressure. This will diffuse into their blood and then into more solid parts of their body. When they ascend, the stored gas diffuses out, causing bubbles, and thus 'the bends'.
When free-diving, the lungs are full of air at one atmosphere of pressure, leading to very different gas absorption dynamics.
Humans who free-dive (i.e. no scuba gear, just hold your breath) "don't get the bends" despite descending to depths well past the recreational scuba levels.
The caveat is that mammals can and do get the bends from free-diving (humans included in the mammals group) if they make multiple dives to depth with insufficient surface intervals. Because when you get technical about it, the air in the lungs does get compressed at depth, leading to the same absorption/release process as SCUBA divers face. However, the volumes of gas are much less (one breath vs many), thus the total amount absorbed/released is much less.
You may know these critters by their more menu-friendly name, Chilean Sea Bass.
I’m amazed that anything biological can live 10km deep. What’s the trick to not having anything meaningfully organic get squished into a paste?
I’m also unsurprised by how “weird” stuff gets the deeper you go. But I’m very surprised by how there’s a few “normal” looking sharks super deep.
Inner cell pressure == outer cell pressure
Anybody know how the background is done? It's a constantly moving light field.
(Much much deeper...) oh, Hi, hoomans
Great site, very informative. I've enjoyed it a lot.
As an improvement, it would be good to add links to Wikipedia articles for each entry.