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Getting large swaths of the seabed is going to be beyond the resources of almost everyone. They spent like $200m hunting for MH370... and didn't find it. And on

Getting large swaths of the seabed is going to be beyond the resources of almost everyone. They spent like $200m hunting for MH370... and didn't find it. And on the scale of the ocean that was not a large swath by any means.

handmodel 4y ago
I'm not going to pretend to be an expert but it seems like the hard/expensive part is probably building the underwater drone capable of taking the LIDAR? I would imagine at some point getting overhead satellite imagery by plane of the entire world seemed impossible - as did street view coverage of the entire US - but not the craziest expense once you have the ability to do it once.
- chowells 4y ago
  The really hard part is the combination of the very short range of light transmission underwater and the very large size of the oceans. How many centuries are you willing to spend on the project?
  - roywiggins 4y ago
    The MH370 search used sonar, which works well underwater but has quite short range so it involved driving ships around on the surface dragging sonar arrays backwards and forwards for years. I think this is one of the systems used during the MH370 search, apparently it can scan 192km² per day. There are 161,000,000 km² of ocean, so you'd need at least a million days or 3,000 years to scan the whole thing, give or take. http://www.slhydrospheric.com/prosas60_spec.html http://www.slhydrospheric.com/prosas60_spec.html
    - handmodel 4y ago
      That sounds extremely slow but presumably now that they've built one the cost to build 100 or 1000 would be achievable if someone (or some government) had the interest. I would think they would need a version that doesn't need the ship nearby to scale - but would still guess this is something that will be accomplished on the order of 30 years from now.
    - narag 4y ago
      There are 161,000,000 km² of ocean... Sorry if you aren't the best choice, but I had to ask someone in the thread. Why? I mean why all the ocean? If the purpose is to find archeological sites, most will be on the continental platform.
      - hetspookjee 4y ago
        _what if_ you find remains of a truly ancient civilisation on the abyssal plains. Now that would get the films rolling!
    - ge96 4y ago
      Would be curious if those gliders were helpful or not/how much smaller.
- bigDinosaur 4y ago
  There's twice as much sea as land, and from a brief glance LIDAR penetrates to 300m (whereas google informs me the average depth of the ocean is ~3600m) as well as presumably some weird topology which might make for interesting challenges. Certainly doesn't sound easy, but it'd be interesting to hear from anyone who works in this area.
irrational 4y ago
Instead of SpaceX, couldn’t Elon musk have funded seaX and created teams to design and build autonomous scanning drones at scale?
VintageCool 4y ago
For the purposes of studying human archaeology, I don't care about the deep sea. I want LIDAR surveys of shallow coastline waters. Global sea levels 20,000 years ago were 125 meters lower than they were today. Our ancestors could have been living on shorelines that are now deep under water. There could be extensive archaeological sites that are undiscovered because they are buried under 60 meters of ocean water. Ancient human tools have been found by fishing boats in Doggerland, the portion of the North Sea that used to be a land bridge between Europe and England. I bet there's a whole lot more discoveries to made just a few miles offshore.
- roywiggins 4y ago
  Yeah, for sure. Doggerland would be top of my list too.
  - yread 4y ago
    Persian Gulf would be a trove

handmodel 4y ago

I'm not going to pretend to be an expert but it seems like the hard/expensive part is probably building the underwater drone capable of taking the LIDAR? I would imagine at some point getting overhead satellite imagery by plane of the entire world seemed impossible - as did street view coverage of the entire US - but not the craziest expense once you have the ability to do it once.

chowells 4y ago
The really hard part is the combination of the very short range of light transmission underwater and the very large size of the oceans. How many centuries are you willing to spend on the project?
- roywiggins 4y ago
  The MH370 search used sonar, which works well underwater but has quite short range so it involved driving ships around on the surface dragging sonar arrays backwards and forwards for years. I think this is one of the systems used during the MH370 search, apparently it can scan 192km² per day. There are 161,000,000 km² of ocean, so you'd need at least a million days or 3,000 years to scan the whole thing, give or take. http://www.slhydrospheric.com/prosas60_spec.html http://www.slhydrospheric.com/prosas60_spec.html
  - handmodel 4y ago
    That sounds extremely slow but presumably now that they've built one the cost to build 100 or 1000 would be achievable if someone (or some government) had the interest. I would think they would need a version that doesn't need the ship nearby to scale - but would still guess this is something that will be accomplished on the order of 30 years from now.
  - narag 4y ago
    There are 161,000,000 km² of ocean... Sorry if you aren't the best choice, but I had to ask someone in the thread. Why? I mean why all the ocean? If the purpose is to find archeological sites, most will be on the continental platform.
    - hetspookjee 4y ago
      _what if_ you find remains of a truly ancient civilisation on the abyssal plains. Now that would get the films rolling!
  - ge96 4y ago
    Would be curious if those gliders were helpful or not/how much smaller.
bigDinosaur 4y ago
There's twice as much sea as land, and from a brief glance LIDAR penetrates to 300m (whereas google informs me the average depth of the ocean is ~3600m) as well as presumably some weird topology which might make for interesting challenges. Certainly doesn't sound easy, but it'd be interesting to hear from anyone who works in this area.

irrational 4y ago

Instead of SpaceX, couldn’t Elon musk have funded seaX and created teams to design and build autonomous scanning drones at scale?

VintageCool 4y ago

For the purposes of studying human archaeology, I don't care about the deep sea. I want LIDAR surveys of shallow coastline waters. Global sea levels 20,000 years ago were 125 meters lower than they were today. Our ancestors could have been living on shorelines that are now deep under water. There could be extensive archaeological sites that are undiscovered because they are buried under 60 meters of ocean water. Ancient human tools have been found by fishing boats in Doggerland, the portion of the North Sea that used to be a land bridge between Europe and England. I bet there's a whole lot more discoveries to made just a few miles offshore.

roywiggins 4y ago
Yeah, for sure. Doggerland would be top of my list too.
- yread 4y ago
  Persian Gulf would be a trove