8 ms·

Second massive “blue hole” found, 270 metres deep

55 points by bandibus 3y ago

deleted 3y ago
[deleted]
ortusdux 3y ago
Very cool. I will note that it is significantly less picturesque than the stock photo used in the article. https://explorersweb.com/taam-ja-blue-hole-mexico/ https://explorersweb.com/taam-ja-blue-hole-mexico/
- bandibus 3y ago
  Thank you! I could definitely have picked a better writeup of this story than the PopMech piece, and this link is much better. Cheers for that.
mxfh 3y ago
What is it with those weird metrics? 147,000 square feet across, this is what science communication picks up from the paper? The major axis of the TJBH at ~10 mbsl was estimated to be ~151.8 m and was oriented ~10.76° clockwise from the north, similar to the main direction of geological faults in the region. The minor axis, perpendicular to the major axis, was ~124.4 m across. The surface area covered by the blue hole is ~13,690 m2 (1.4 ha) with an external perimeter of ~492.7 m. The structure of the blue hole can be described as a conic shape that is north-skewed with a volume of ~1 million m3. Why not about 140m (450 ft) diameter? The full open access article is here: https://www.frontiersin.org/articles/10.3389/fmars.2023.1141160/full https://www.frontiersin.org/articles/10.3389/fmars.2023.1141...
- Izkata 3y ago
  The conversion from square meters to square feet is 13690 * 3.28 * 3.28 = 147282.496, so at least it's the correct number for area. But yeah, adding "across" sounds weird there. Edit: Actually for a much easier visual, it's right about 2.5 American football fields.
  - kwhitefoot 3y ago
    > a much easier visual, it's right about 2.5 American football fields. One that means absolutely nothing to the majority of the people on the planet.
    - speedgoose 3y ago
      I think it was a joke. But I’m not sure.
      - Izkata 3y ago
        Not a joke, the article converted from meters to feet so the demographic limitation is ~the same. Don't know why the title on HN uses metres, the original title doesn't have any size. I only included "American" because I knew someone would jump on it with soccer/non-American football fields.
        speedgoose 3y ago
        Alright. The American obsession to use random things instead of the international system of units is weird and funny so I thought you were joking about it.
        rbanffy 3y ago
        > I knew someone would jump on it with soccer/non-American football fields. There is no such thing as "soccer". The correct name is "football", because you use your feet to move the ball inside the field during the game. There is also American football, which is an entirely different game, that's neither played with feet, or a ball. ;-P
        CydeWeys 3y ago
        You might do well to read up on the history of asSOCiation football.
        3y ago
- havefunbesafe 3y ago
  "Tim Newcomb is a journalist based in the Pacific Northwest. He covers stadiums, sneakers, gear, infrastructure, and more for a variety of publications, including Popular Mechanics." Could be why.
aaron695 3y ago
Google maps - https://goo.gl/maps/DddfusRBWZ6WtCV19 https://goo.gl/maps/DddfusRBWZ6WtCV19 Easier to see on Google Earth on a less windy day. Search "Taam Ja’ Blue Hole"
hamandcheese 3y ago
> Our knowledge of blue holes is limited by accessibility issues, sometimes due to opening being too small or the depths being so great, and sometimes due to limited oxygen in the water, making it dangerous to explore without specialized equipment. I'm curious why lack of oxygen is a problem? We don't breathe water, so why should oxygen content matter?
- nradov 3y ago
  Right, any explorers would dive with their own breathing gas. The actual risk in some of those blue holes is not low oxygen but high hydrogen sulfide.
- hkchad 3y ago
  Not sure if it's the case here but typically a low o2 underwater environment means a high concentration of Hydrogen Sulfide. This can have corrosive effects on some scuba gear and generally makes visibility very poor. I've crossed through a H2S layer in a Mexican Cenote (fresh water on top, H2S in middle, Salt on bottom) it was only a few feet thick, it's not something I'd want to spend a lot of time in though. Even though you are on SCUBA you can still smell and taste it and it's not pleasant.
driggs 3y ago
What makes blue holes so fascinating, in my opinion, is the historical perspective they provide. These were once deep air-filled vertical shafts, formed by the longterm erosional/dissolutional power of falling water under the influence of gravity. Speleothems like stalactites prove that they formed in an air-filled environment. In other words, the present-day sea level at the Yucatan Peninsula was formerly at least 275m lower; and/or the present-day surface was at least 275m higher. The paper attributes this to "glacio-eustatic changes", which is the equal-and-opposite-reaction involving lowered sea level (increased global glaciation) and the buoyant rising of the regional continental crust since the mass of additional sea water has been removed.
beembeem 3y ago
At first I assumed this was the one near Belize, which is quite well known in the scuba diving community [1]. In fact, the picture on this post is probably of that one. However, this new one is over twice as deep! [1] https://en.wikipedia.org/wiki/Great_Blue_Hole https://en.wikipedia.org/wiki/Great_Blue_Hole
zwieback 3y ago
I'll see your blue hole and raise a "Blautopf" near where I grew up: https://en.wikipedia.org/wiki/Blautopf https://en.wikipedia.org/wiki/Blautopf Rayleigh scattering on nanoscale limestone particles!
thinkling 3y ago
I hope they sterilized all the equipment before lowering it into the hole... Surely?
osamagirl69 3y ago
Worth pointing out, the image in the article is actually of the 'Great Blue Hole' off the coast of Belize, which is about twice the diameter but half the depth[1] of the one in the paper. Also quite the opposite of 'recently discovered'; it has been one of the best known diving spots in the world for over 50 years, and one of the very few ocean floor features that I can recognize by eye... https://en.wikipedia.org/wiki/Great_Blue_Hole https://en.wikipedia.org/wiki/Great_Blue_Hole
- deleted 3y ago
  [deleted]
JohnClark1337 3y ago
[dead]
deleted 3y ago
[deleted]
culi 3y ago
What is it with articles like these still using language like "discovered" > Guided by tips from fishermen, scientists from Colegio de le Frontera Sur explored a tropical estuary off the southeastern coast > the scientists names their new discovery the Taam ja' Blue Hole, using the Mayan language phrase Clearly the locals have known about this already. If your argument is that the difference is when it's published in some scientific paper then that's also contradictory to: > the new blue hole was discovered in 2021, the researchers only recently detailed their findings in a study published in Frontiers in Marine Science "Discovered in 2021" pretty obviously means Western people here. If it was about "scientific description" then we would've said 2023. It reminds me of that one white person that traveled to Mexico and "discovered" a variety of corn that produces a mucus-like goo that traps nitrogen from the air itself instead of using bacteria. This variety had an indigenous name and the people who've been growing it for thousands of years could trace back their entire lineage of people who've developed the variety specifically to grow in those low-nitrogen conditions
- red_trumpet 3y ago
  Yeah talking about discovery is weird. The title even says it "just showed up" making me think there was a geologic events involved. Though I wouldn't dismiss any relevance of the year 2021, as that was when the scientists did their field work. Imagine another team did study the same hole in 2022 but published earlier, then that would be relevant.
- biorach 3y ago
  > Clearly the locals have known about this already Clearly they knew there was a small patch of deep water. Maybe not much more than that. I think you're being way too quick to jump to self righteousness
- driggs 3y ago
  Because its depth was discovered by researchers in 2021. The Mayans knew that it was a blue hole. They didn't know that it was among the deepest known in the world, simply that it was one of many blue holes.
- s1artibartfast 3y ago

55 points by bandibus 3y ago

deleted 3y ago

[deleted]

Very cool. I will note that it is significantly less picturesque than the stock photo used in the article. https://explorersweb.com/taam-ja-blue-hole-mexico/ https://explorersweb.com/taam-ja-blue-hole-mexico/

bandibus 3y ago
Thank you! I could definitely have picked a better writeup of this story than the PopMech piece, and this link is much better. Cheers for that.

mxfh 3y ago

What is it with those weird metrics? 147,000 square feet across, this is what science communication picks up from the paper? The major axis of the TJBH at ~10 mbsl was estimated to be ~151.8 m and was oriented ~10.76° clockwise from the north, similar to the main direction of geological faults in the region. The minor axis, perpendicular to the major axis, was ~124.4 m across. The surface area covered by the blue hole is ~13,690 m2 (1.4 ha) with an external perimeter of ~492.7 m. The structure of the blue hole can be described as a conic shape that is north-skewed with a volume of ~1 million m3. Why not about 140m (450 ft) diameter? The full open access article is here: https://www.frontiersin.org/articles/10.3389/fmars.2023.1141160/full https://www.frontiersin.org/articles/10.3389/fmars.2023.1141...

Izkata 3y ago
The conversion from square meters to square feet is 13690 * 3.28 * 3.28 = 147282.496, so at least it's the correct number for area. But yeah, adding "across" sounds weird there. Edit: Actually for a much easier visual, it's right about 2.5 American football fields.
- kwhitefoot 3y ago
  > a much easier visual, it's right about 2.5 American football fields. One that means absolutely nothing to the majority of the people on the planet.
  - speedgoose 3y ago
    I think it was a joke. But I’m not sure.
    - Izkata 3y ago
      Not a joke, the article converted from meters to feet so the demographic limitation is ~the same. Don't know why the title on HN uses metres, the original title doesn't have any size. I only included "American" because I knew someone would jump on it with soccer/non-American football fields.
      - speedgoose 3y ago
        Alright. The American obsession to use random things instead of the international system of units is weird and funny so I thought you were joking about it.
      - rbanffy 3y ago
        > I knew someone would jump on it with soccer/non-American football fields. There is no such thing as "soccer". The correct name is "football", because you use your feet to move the ball inside the field during the game. There is also American football, which is an entirely different game, that's neither played with feet, or a ball. ;-P
        CydeWeys 3y ago
        You might do well to read up on the history of asSOCiation football.
        3y ago
havefunbesafe 3y ago
"Tim Newcomb is a journalist based in the Pacific Northwest. He covers stadiums, sneakers, gear, infrastructure, and more for a variety of publications, including Popular Mechanics." Could be why.

aaron695 3y ago

Google maps - https://goo.gl/maps/DddfusRBWZ6WtCV19 https://goo.gl/maps/DddfusRBWZ6WtCV19 Easier to see on Google Earth on a less windy day. Search "Taam Ja’ Blue Hole"

hamandcheese 3y ago

> Our knowledge of blue holes is limited by accessibility issues, sometimes due to opening being too small or the depths being so great, and sometimes due to limited oxygen in the water, making it dangerous to explore without specialized equipment. I'm curious why lack of oxygen is a problem? We don't breathe water, so why should oxygen content matter?

nradov 3y ago
Right, any explorers would dive with their own breathing gas. The actual risk in some of those blue holes is not low oxygen but high hydrogen sulfide.
hkchad 3y ago
Not sure if it's the case here but typically a low o2 underwater environment means a high concentration of Hydrogen Sulfide. This can have corrosive effects on some scuba gear and generally makes visibility very poor. I've crossed through a H2S layer in a Mexican Cenote (fresh water on top, H2S in middle, Salt on bottom) it was only a few feet thick, it's not something I'd want to spend a lot of time in though. Even though you are on SCUBA you can still smell and taste it and it's not pleasant.

driggs 3y ago

What makes blue holes so fascinating, in my opinion, is the historical perspective they provide. These were once deep air-filled vertical shafts, formed by the longterm erosional/dissolutional power of falling water under the influence of gravity. Speleothems like stalactites prove that they formed in an air-filled environment. In other words, the present-day sea level at the Yucatan Peninsula was formerly at least 275m lower; and/or the present-day surface was at least 275m higher. The paper attributes this to "glacio-eustatic changes", which is the equal-and-opposite-reaction involving lowered sea level (increased global glaciation) and the buoyant rising of the regional continental crust since the mass of additional sea water has been removed.

beembeem 3y ago

At first I assumed this was the one near Belize, which is quite well known in the scuba diving community [1]. In fact, the picture on this post is probably of that one. However, this new one is over twice as deep! [1] https://en.wikipedia.org/wiki/Great_Blue_Hole https://en.wikipedia.org/wiki/Great_Blue_Hole

zwieback 3y ago

I'll see your blue hole and raise a "Blautopf" near where I grew up: https://en.wikipedia.org/wiki/Blautopf https://en.wikipedia.org/wiki/Blautopf Rayleigh scattering on nanoscale limestone particles!

thinkling 3y ago

I hope they sterilized all the equipment before lowering it into the hole... Surely?

osamagirl69 3y ago

Worth pointing out, the image in the article is actually of the 'Great Blue Hole' off the coast of Belize, which is about twice the diameter but half the depth[1] of the one in the paper. Also quite the opposite of 'recently discovered'; it has been one of the best known diving spots in the world for over 50 years, and one of the very few ocean floor features that I can recognize by eye... https://en.wikipedia.org/wiki/Great_Blue_Hole https://en.wikipedia.org/wiki/Great_Blue_Hole

deleted 3y ago
[deleted]

JohnClark1337 3y ago

[dead]

deleted 3y ago

[deleted]

culi 3y ago

What is it with articles like these still using language like "discovered" > Guided by tips from fishermen, scientists from Colegio de le Frontera Sur explored a tropical estuary off the southeastern coast > the scientists names their new discovery the Taam ja' Blue Hole, using the Mayan language phrase Clearly the locals have known about this already. If your argument is that the difference is when it's published in some scientific paper then that's also contradictory to: > the new blue hole was discovered in 2021, the researchers only recently detailed their findings in a study published in Frontiers in Marine Science "Discovered in 2021" pretty obviously means Western people here. If it was about "scientific description" then we would've said 2023. It reminds me of that one white person that traveled to Mexico and "discovered" a variety of corn that produces a mucus-like goo that traps nitrogen from the air itself instead of using bacteria. This variety had an indigenous name and the people who've been growing it for thousands of years could trace back their entire lineage of people who've developed the variety specifically to grow in those low-nitrogen conditions

red_trumpet 3y ago
Yeah talking about discovery is weird. The title even says it "just showed up" making me think there was a geologic events involved. Though I wouldn't dismiss any relevance of the year 2021, as that was when the scientists did their field work. Imagine another team did study the same hole in 2022 but published earlier, then that would be relevant.
biorach 3y ago
> Clearly the locals have known about this already Clearly they knew there was a small patch of deep water. Maybe not much more than that. I think you're being way too quick to jump to self righteousness
driggs 3y ago
Because its depth was discovered by researchers in 2021. The Mayans knew that it was a blue hole. They didn't know that it was among the deepest known in the world, simply that it was one of many blue holes.
s1artibartfast 3y ago