[HN Gopher] Satellite data reveal nearly 20k previously unknown ...
___________________________________________________________________
Satellite data reveal nearly 20k previously unknown deep-sea
mountains
Author : Brajeshwar
Score : 119 points
Date : 2023-05-01 15:07 UTC (7 hours ago)
(HTM) web link (www.sciencenews.org)
(TXT) w3m dump (www.sciencenews.org)
| radicaldreamer wrote:
| I wonder if the navies have secret high resolution maps of the
| sea floor for submarine operations...
| jedc wrote:
| (Former US submariner)
|
| Yes, and no.
|
| Yes- the US has maps with higher-resolution data on water depth
| around the world than what's commercially available.
|
| No - those maps aren't perfect. Some areas are extraordinarily
| well-mapped, others are less so.
|
| Submarine crews are trained not to check just the charts that
| are in use for a particular voyage, but also other charts
| covering the same area. (The USS San Francisco collision has no
| evidence of a seamount on the charts in use, but there was
| "discoloration" on another chart covering the same area.)
| GalenErso wrote:
| They do, but these maps are either incomplete, or they don't
| always follow them.
|
| The Los Angeles-class nuclear submarine USS San Francisco
| (SSN-711) nearly sank on January 8, 2005, when it hit an
| uncharted undersea mountain about 364 nautical miles (675 km)
| southeast of Guam while operating at flank (maximum) speed at a
| depth of 525 feet (160 m). [1]
|
| The Seawolf-class nuclear powered fast attack submarine USS
| Connecticut (SSN-22) suffered damage on October 2, 2021, after
| it collided with an undersea mountain while maneuvering in the
| South China Sea. [2]
|
| And the Swiftsure-class nuclear powered fast attack submarine
| HMS Superb (S109) had to be decommissioned ahead of schedule
| due to the damage it suffered during a collision with an
| underwater pinnacle in the Red Sea, 80 miles (130 km) south of
| the Suez Canal. [3]
|
| [1]
| https://en.wikipedia.org/wiki/USS_San_Francisco_(SSN-711)?us...
|
| [2]
| https://en.wikipedia.org/wiki/USS_Connecticut_(SSN-22)?usesk...
|
| [3]
| https://en.wikipedia.org/wiki/HMS_Superb_(S109)?useskin=vect...
| contingencies wrote:
| Makes you wonder why they don't have forward-facing sonar as
| standard during non-secret ops. I mean, there's not a whole
| lot of shifty things you can be doing off Guam, if you
| already own the place.
| count wrote:
| The position of most submarines at any given point is
| considered actually secret, especially if it is underwater.
| Great expense is undertaken to monitor and listen for other
| countries undersea vehicles as well.
| jedc wrote:
| former US submariner here:
|
| * forward-facing sonar is always being used at all times
| while a submarine is underway
|
| * however, the sonar that's always used is passive, and
| since mountains don't move, passive sonar doesn't find them
|
| * active sonar could theoretically be used, but the risk of
| communicating a submarine's position relative to the chance
| that you'd hit an underwater mountain is balanced strongly
| on the side of running silent.
| contingencies wrote:
| Thanks for sharing an informed perspective!
| jakear wrote:
| What do you think would be easier: tracking a sub when you
| have tons of data linking your clandestine sensors'
| information to their location as broadcast by sonar, or
| when you don't?
| wongarsu wrote:
| There's always training as a good excuse for running
| silent. Apart from that ... well, I'm not quite sure what
| these fast attack submarines are doing out and about at
| all. Maybe looking for other subs in the area? But whatever
| they are doing probably benefits from being hard to detect.
| If you are comfortable with announcing yourself with active
| sonar and are not just on the way to somewhere else, why
| not just use a surface ship in the first place?
| cromwellian wrote:
| "Most of the newly discovered underwater mountains are on the
| small side -- between roughly 700 and 2,500 meters tall". 2500
| meters is small? Even 700 meters is almost as tall as the Burj
| Dubai. I'd call 2500 meters a decent sized mountain.
| dylan604 wrote:
| If you're in a submarine that is only 10m tall, 700m is huge.
| It seems like a pretty good idea to know where they are
| notahacker wrote:
| Depends on your point of reference though; the lowest lying
| lowland is around 3600m "tall" when measured from average ocean
| floor depth rather than sea level, and a 2500m seamount might
| be sitting in a valley surrounded by the underwater edges of
| continental shelf that's at least twice as high as it. By our
| usual standards, they're -1000m tall :)
| nunuvit wrote:
| You may enjoy the movie The Englishman Who Went Up a Hill But
| Came Down a Mountain.
| alejohausner wrote:
| Here is the data: https://zenodo.org/record/7718512
| kachnuv_ocasek wrote:
| Here's a link to the original article (open access) with figures
| and all that:
| https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/202...
| abudabi123 wrote:
| Wonder if these satellites see naked human skeletons inside
| submarines now or in the near future.
| lingqingm wrote:
| [dead]
| RcouF1uZ4gsC wrote:
| > However, it's possible that some could pose a risk to mariners.
| "There's a point when they're shallow enough that they're within
| the depth range of submarines," says David Clague, a marine
| geologist at the Monterey Bay Aquarium Research Institute in Moss
| Landing, Calif., who was not involved in the research.
|
| It would be interesting to see what proportion of these 20k deep-
| sea mountains were actually known to either the US or Soviets as
| part of their submarine support.
|
| Knowing the location of these deep-sea mountains could be very
| valuable when you are engaged in submarine cat and mouse games
| with nuclear submarines.
|
| My guess is that quite a few were known but classified as a
| national security matter.
| asicsp wrote:
| Dupe: "More than 19k undersea volcanoes discovered"
|
| https://news.ycombinator.com/item?id=35662580 _(134 points | 9
| days ago | 92 comments)_
| officeplant wrote:
| My favorite part of the article is the mention of the submarine
| hitting an uncharted sea mount. I rarely think about the fact
| that they can't just leave sonar on at all times to be aware of
| their surroundings and often rely on known mapping data.
| whatever1 wrote:
| But why submarines do not have a tethered drone traveling I
| don't know, 1 mile ahead of them and hit such obstacles?
| asdfman123 wrote:
| Cost and complexity is probably one part of it.But more
| importantly, I imagine having a drone ahead of them would
| generate noise, thus decreasing stealth.
|
| It's probably one of those things that shouldn't happen if
| you're doing everything else the "right" way.
| Thrymr wrote:
| It would not be trivial to design an separate underwater
| vehicle that could travel ahead of a submarine at flank speed
| (>30 knots), let alone do so quietly.
| passwordoops wrote:
| I'd love to see more satellite-based underwater archaeology,
| seeing how far sea levels rise after the last glacial period. A
| lot of human history is probably out on the continental shelves.
|
| See, for example, Doggerland beneath the English Channel:
| https://en.m.wikipedia.org/wiki/Doggerland
| z3c0 wrote:
| Another example: the underwater structures off the coast of
| Cuba
|
| https://en.m.wikipedia.org/wiki/Cuban_underwater_formation
| adastra22 wrote:
| At 600+ meters of depth, those are almost certainly not of
| human origin. There are many examples of these sorts of
| phenomena, which derive their regular shapes from the way
| crystalline minerals fracture.
| whydoyoucare wrote:
| I am curious now - at what depths is it considered human
| origin? Is it because we know how much the sea level has
| risen in the last x years?
| paganel wrote:
| More aerial Lidar-based archeology would also be pretty cool.
|
| It seems that there was a strong momentum in that direction a
| few years ago but recently I've stopped hearing about it (or at
| least not that often compared to the recent past).
| akiselev wrote:
| LIDAR has made a splash in archaeology last few years,
| especially in South America where the jungles cover up all
| the ruins. See [1][2][3] etc
|
| You haven't heard much about it because everyone is
| scrambling for funding to go excavate these ruins in person.
|
| [1] https://www.nationalgeographic.com/history/article/maya-
| lase...
|
| [2] https://www.thearchaeologist.org/blog/lidar-technology-
| confi...
|
| [3] https://arstechnica.com/science/2021/10/lidar-reveals-
| hundre...
| dr_dshiv wrote:
| Do you think we will discover some frequency of light that will
| let us map the ocean floors as you imagine?
| netcraft wrote:
| AFAIK there are no frequencies of the electromagnetic
| spectrum we are not aware of, but our techniques and signal
| processing can potentially improve. There are also
| frequencies of waves other than light that we can use, such
| as sonar - but not from a satellite of course.
| daveslash wrote:
| It's not really about the frequency of light. We pretty much
| have "discovered" all frequencies -- it's the electromagnetic
| spectrum. We know all of the frequencies that exist. The
| trick is devising new methods with increasingly sensitive
| instrumentation.
|
| This article talks about how researchers looked at
| measurements taken from space to gauge where the sea level
| was a mere few-centimeters higher than the surrounding area!
| Incredible! In theory, I could have seen someone like Arthur
| C. Clarke proposing this half a century ago - but with the
| precision in instrumentation only becoming available today,
| the idea could have been proposed long before the technology
| existed.
|
| In the future, might we devise a method and accompanying
| instrumentation that will allow us to map the sea floor with
| just a regular flash light hung from a ship? Maybe (but
| probably not). Point being: It's the methodology +
| instrumentation, not the frequency of light itself.
| paulusthe wrote:
| It's not probably out there, it's definitely out there. One of
| the absolute best places to be a hunter gatherer is in river
| deltas and low lying floodplains. If we could magically lower
| sea levels by 100m, we'd find evidence of humanity not only in
| doggerland but off the coast of Africa, China, Australia, and
| more.
|
| In fact some archaeologists are planning future underwater digs
| based on today's topographical hints of ancient riverbeds now
| underwater. There's a massive one off Bengal, another one near
| Ceylon, and a few more I can't remember right now.
| malux85 wrote:
| Could these places be a source for gold? Were these cultures
| advanced enough to be mining and smelting gold?
| BurningFrog wrote:
| We know very close to nothing about them, so the answer to
| most such questions is "maybe".
| shrubble wrote:
| They definitely would be a good place to search. Not only
| for historical artifacts but becuase the plains would trap
| the heavier gold flakes that got eroded either locally or
| upstream.
|
| For instance the state of Pennsylania has no known gold
| vein deposits but small flakes of gold are often found in
| the rivers, since the quartz rocks that contained the
| flakes were eroded, freeing the flakes which are then
| washed into the river by rain.
| jewayne wrote:
| So, your first thought when searching for artifacts from
| the ancient past is whether they can be melted down into
| commodities?
| Teever wrote:
| A more charitable interpretation of the comment that you
| replied to is that the artifacts may be located near
| ancient gold mines, and after we've retrieved the
| artifacts during excavation then we could potentially
| continue to mine the valuable resources in the same
| location.
| mxkopy wrote:
| I think GP might've been sarcastic, but even if not,
| there's no need to be charitable to such a caricaturistic
| intent to extract resources.
| AlotOfReading wrote:
| Any implication that archaeologists are remotely
| interested in gold or that there's monetary profit to be
| had from excavations is almost always destructive to the
| cause of heritage programs.
|
| I've done anti-looting programs in various places around
| the world as part of excavations. The belief that gold
| and other precious artifacts will be found is one of the
| most common causes/justifications for looting. Moreover,
| the belief that archaeologists are motivated or will in
| any way help to find precious metals is utterly corrosive
| to our ability to work with local authorities because it
| reduces trust and incentivises preemptive looting
| whenever we show up, among other things.
|
| Let me emphasize this: finding precious metals _sucks_.
| It means you have a lot more paperwork, it means you get
| a lot more looting, it means a lot of government
| interest, it means treasure hoard laws apply, future
| excavation decisions become far more political, etc. It
| 's a massive pain in the butt all around.
| lazyasciiart wrote:
| > I've done anti-looting programs in various places
| around the world as part of excavations.
|
| This sounds fascinating, do you know of anywhere I can
| read about this kind of work?
| AlotOfReading wrote:
| It's way more boring than you're thinking. The goal is to
| reduce looting by
|
| 1) educating people about the harm it does
|
| 2) convince the audience that whatever goals might be
| sought in looting are unlikely to be met (profit, cool-
| stuff-factor, "helping archaeologists", etc)
|
| 3) Ensuring site security and getting legal frameworks in
| place to monitor/enforce heritage preservation.
|
| The first is usually pretty easy. The NPS used to have
| this video called "Assault on Time" that they show to
| people. People who don't want to fill out requisition
| forms from the government usually just show pictures of
| looted sites. I had a professor who liked to use pictures
| of Mimbres sites in New Mexico. I prefer to use Ai-
| Khanoum because the before [0] and after [1] is so stark.
|
| For the second, usually this takes the form of inviting
| locals out to see what you're excavating and showing them
| any finds. This will usually be rocks, charcoal, lithics,
| and other profoundly unprofitable things. It also
| humanizes the historical people to help locals build
| personal connections with the sites. In a lot of cases
| you'll also be hiring locals to help with the
| excavations, so they know there's nothing hidden because
| they're present for everything.
|
| This usually isn't effective on the "collectors" and
| "metal detectorists" (see e.g. _Coping with Site Looting_
| [2]), so other things are necessary. That tends to be
| site monitoring and heritage protection laws, which
| depend on the country and situation. Sometimes it 's best
| to just invite local officials to the site. Meeting with
| important officials can be very inconvenient though. Ever
| tried getting wrinkles out of a suit in a field site 2
| days from the nearest city? Those clothes did _not_
| survive the expedition.
|
| That's just the lowest level of cooperation that has to
| happen as well. The key is having embedded experts making
| connections with the people who can implement those laws
| and fines, then enforce them. This is also the level most
| affected by the budgetary constraints of heritage
| programs globally. Last I checked, there were fewer than
| 100 positions for this sort of work available in the US
| every year. Some countries may have less than a dozen
| people total.
|
| [0] https://en.wikipedia.org/wiki/File:Ai_Khanoum_landsca
| pe_phot...
|
| [1] https://m.psecn.photoshelter.com/img-
| get/I0000lqdxnldw3QE/s/...
|
| [2]
| http://npshistory.com/series/archeology/seac/rapp/1.pdf
| throwbadubadu wrote:
| Erm, just no and that wasn't necessary, or GPT?
| mywacaday wrote:
| I used to lifeguard on a beach in Ireland, on a very low tide
| and if the sand had shifted there were solid black slimy
| things just under the sand, turns out they were the remains
| of an ancient oak forest, would be amazing to see what 100m
| would should, that was only 3-4 meters.
___________________________________________________________________
(page generated 2023-05-01 23:00 UTC)