Bermuda will sink...too.

[King of the Americas]

So, there 'might' have been an island or group of them known in ancient history as "Atlantis", and this place 'may' have "sank into the sea", to be GONE completely without a single trace left...

IF such a thing could happen...could it happen again, and what in our world might suffer the same fate?

The answer is "Bermuda".

That Northern tip of the infamous "Bermuda Triangle".

I know what you are thinking..."Woo woo crap coming!"

Nope not at all. Bermuda sits atop an hourglass figure of land, in water more than a mile deep. Each day the top most portion of Bermuda grows wider with coral, while a half a mile down the pedistal it sits on gets pounded by the gulf stream, huricanes, and the massive forces that must be accumulting above.

This hour glass pedistal is situated over an old volcano, and could have been just one in a series of islands, formed exactly as Bermuda was. I fear that Bermuda's narrow submerged waist, will someday give way...and an entire island will 'sink' and be gone forever...

Use Google Earth, and check out the ocean to the South West of Bermuda.

Are the 'lines' therein, shipping lanes?

 

[Cainkane1]

Part of Port Royal sure sank under the waves in that area.

 

[MRC_Hans]

Slight correction: Hurricanes don't pound anything a half mile down. And currents don't do much to solid structures.

Do you have a scale for this? I mean how deep is the undercut, compared to the width of the atoll plateau? The Bermuda atoll is some 17 miles long and 11 miles wide, and the ocean depth around it is about 5 miles. That is more like a pancake than an hour-glass. IF something is to happen due to an undercut, it is more likely to be chips coming off the edge that the whole thing toppling. After all, lay Bermuda on the ocean floor on its short side, and it would stick several miles into the air. Not likely to happen.

Shipping lanes? That region is one of the densest trafficked parts of the world's oceans.

ETA: Oh, and don't be fooled by elevations and depths on Google Earth, they are exaggerated. Scale Earth to the size of a billiards ball, and it will be smother than a billiards ball.

Hans

 

[King of the Americas]

Pull up your Google Earth, and check out the 'lines' I am referring to.

Bermuda is the very 'tip' of a what must have been a volcanic spire, from the bottom of the ocean. It's cross section from its tip to the ocean floor looks 'hour glass like like', not in so much as a 'tiny' mid-section, but rather a noticably more narrow in the middle, appearance.

If, you'll again, use G.E. and check out what lies to the North East of Bermuda...

You can't see the hour glass shape I am referring to, and I haven't found a link to demonstrate this yet... I just caught the disputable fact at the end of a program on the History Channel, or something like it.

This is the FIRST place I stop, when I come across such things.

 

[Correa Neto]

So, there 'might' have been an island or group of them known in ancient history as "Atlantis", and this place 'may' have "sank into the sea", to be GONE completely without a single trace left...

IF such a thing could happen...could it happen again, and what in our world might suffer the same fate?

An island diappearing under the sea? Yes, its possible, there are a number of phenomena that may account for this, some catastrophic, some not. It has happened countless times before and will happen again. Without leaving a trace? Sorry, but this is highly unlikeky.

The answer is "Bermuda".

That Northern tip of the infamous "Bermuda Triangle".

I know what you are thinking..."Woo woo crap coming!"

Nope not at all. Bermuda sits atop an hourglass figure of land, in water more than a mile deep. Each day the top most portion of Bermuda grows wider with coral, while a half a mile down the pedistal it sits on gets pounded by the gulf stream, huricanes, and the massive forces that must be accumulting above.

This hour glass pedistal is situated over an old volcano, and could have been just one in a series of islands, formed exactly as Bermuda was. I fear that Bermuda's narrow submerged waist, will someday give way...and an entire island.

Sorry, but you are wrong. Oceanic mountains, not even those with atolls at the top are hourglass-shaped. They are shaped like... Mountains. Coral reefs growing over oceanic volcanoes will not grow horizontally, forming a mushroo-shaped shelf expanding beyond the mountain's top. The reef will grow vertically, and if eventually the growth rate is exceeded by erosion and/or by a positive (local or regional) sea-level raise rate, the atoll will "sink".

The structure of atolls is known since the times of Darwin.

Hourglass-shaped mountains is woo crap, indeed.

You will have to look for another mechanism to account for the sinking of any island at this planet.

 

[JoeTheJuggler]

I believe the older Hawaiian islands are gradually "sinking" (if nothing else but by erosion) while the youngest ones are still over the active spot and growing due to vulcanism. Looking at the ages and sizes of the islands from the southeast to the northwest is like seeing a time lapse of an island sinking.

So?

The Atlantis story is most likely a complete myth. There's no evidence of any connection with anything going on now.

 

[Wauthan]

Darn it. I must be falling out of the loop again. Wasn't the Atlantis myth "originally" derived from the devastation of the Santorini eruption? Or was it just a poorly written metaphor about how it's not a good idea to upset the status quo?

Are there any geological evidence of islands "sinking"? I know of some that blew up and a few that had their tops eroded away but I never heard of one that actually crumbled due to structural collapse.

 

[Soapy Sam]

An island can sink relative to sea level while actually rising relative to an average sphere of the Earth's crust.
Or to put it another way, the water can rise and drown it.
Consider the south coast of England, where several river valleys are now tidal way upstream thanks to post glacial sea level rise, the rivers having previously cut down to the lower, glacial sea level.
By contrast, Scotland has several raised beach structures, demonstrating that Scotland is rising (through isostatic uplift) faster than climatic warming is raising sea level and proving that God is , as suspected, a true Scotsman.
Anything can sink if the water it is in gets deeper. This is not rocket hydraulics.

 

[Correa Neto]

Darn it. I must be falling out of the loop again. Wasn't the Atlantis myth "originally" derived from the devastation of the Santorini eruption? Or was it just a poorly written metaphor about how it's not a good idea to upset the status quo?

There are a number of places pointed as possible templates for the Atlantis myth. Akrotiri is one of them, just like Helike, Troy...

Are there any geological evidence of islands "sinking"? I know of some that blew up and a few that had their tops eroded away but I never heard of one that actually crumbled due to structural collapse.

Massive explosive volcanic eruptions with caldera formation (examples- Santorini and Krakatoa), earthquakes (Port Royal) and eventually some massive landslides (example- Hawaii) can potentially create big changes to an island's landscape, submerging large parts of it. Tsunamis can temporarily flood them. While these phenomena can not completely "sink" an island, they can be more than enough to make a city disappear and trigger the myth of a sunken island. Note that the bigger the island, the smaller will be the relative damage, more parts of it will be preserved after the formation of a volcanic caldera, for example.

An actual sinking is possible only in the lines described by Soapy Sam. And it will be slow.

 

[Soapy Sam]

Slow, yes, if the island is high to begin with, but the critical bit in a sinking is when the water closes over the top, which can happen in one high tide if the land is only just above mean high tide level.
I'd expect a sinking to coincide with a storm surge. The island might take another century or so to vanish finally below the waves, but it would be evacuated at first submergence.
I suspect several island groups may be near that stage at any time, as well as some mainland nations. The Netherlands are the obvious example.

 

[dogjones]

Who cares? I live on a hill. Oh, wait, the shops... MAN THE PUMPS!

 

[shadron]

The original of Atlantis is a feature of one of Plato's books - that makes it Classical Greek in age. It's template *may* have been the explosion of the island of Santorini (in the Mediterranean), which wiped out most of the Minoan civilization on Crete and may well have played havoc with some of the ancient Greek civilization, the one that preceeded the Classical one and a influx of people from Asia into the area at about 1000BC. If so, it would have been no more than a legend by that time. Plato uses it as a vehicle for his writing purposes, and, while not explicitly stating it is mythical or out-and-out fictional, doesn't otherwise embellish on it either. That is the product of later writers.

Hawaii underlies a hot spot that has caused volcanoes in a long, long row to have emerged from the sea bed, only to be later abandoned as the crust pulls on past the mantle plume. The Big Island is soon to be replaced by a new island that is growing to its southeast, and is due to break the surface in a couple of thousand years, give or take. Meanwhile, the ocean has eroded the previous "Big Islands" all the way back to where the chain disappears into the Aleutian trench. It forms the classic (classic since the 1970s, anyway) geological study in plate tectonics. There are over 200 other recognized hot spots on the earth, including Yellowstone and the Galapagos and Falkland Islands.

Google for more information; these are fascinating studies. Some good links:
http://en.wikipedia.org/wiki/Santorini
http://www.drgeorgepc.com/TsunamiSantorin.html (not bad, even if he can't spell)
http://www.santorini.gr-santorini.com/santorinivolcano/atlantisaffect_egypt.htm (step lightly through the wooo here!)
http://en.wikipedia.org/wiki/Hotspot_(geology)
http://pubs.usgs.gov/gip/dynamic/hotspots.html

 

[shadron]

In an aside, a wooo from a well-known institute of wooo in Boulder, Colorado had an article published in 1995 in a Sunday supplement of the Denver Post. In a large, illustrated double page spread he enlightened us about how everything west of Boulder (west!) was to become shallow sea by 1999. I had that pinned up in my cubicle for several years, but lost in it a rather fire-sale sort of move that assails tech firms now and then. It amused me how the marketing types (no stereotypes here, nosir!) would stroll by, read it, and become concerned as the end drew nearer.

 

[shadron]

An island can sink relative to sea level while actually rising relative to an average sphere of the Earth's crust.
Or to put it another way, the water can rise and drown it.
Consider the south coast of England, where several river valleys are now tidal way upstream thanks to post glacial sea level rise, the rivers having previously cut down to the lower, glacial sea level.
By contrast, Scotland has several raised beach structures, demonstrating that Scotland is rising (through isostatic uplift) faster than climatic warming is raising sea level and proving that God is , as suspected, a true Scotsman.
Anything can sink if the water it is in gets deeper. This is not rocket hydraulics.

The Caribbean shore of the southern US is slowly sinking due to weakening and stretching of the basement rock under the area (further due to a "failed" rift, similar to that in the African rift valley). It is also responsible for the largest earthquakes recorded on the NA continent, near New Madrid, Missouri in 1800. The subsidence used to be compensated for by the Mississippi River dropping sediment to build the area back up, but the Corps of Engineers has put a stop to that. Most of the early forts in the area (war of 1812 and all) are now 6-8 feet deep in water, and it is why the cemeteries in New Orleans occasionally give up their dead in a most unsavory way.

 

[Soapy Sam]

Scotland has many faults of similar age to the Reelfoot Rift structure that underlies the New Madrid Zone.
Several of them show evidence of Hoilocene movement. What they lack is the loess & alluvium cover that NM has over the Carb. Limestone, so there's not the same amplification / liquefaction problem. Thanks to recent glaciation, we have little soil to liquefy.
I think it was 1812 by the way. Or thereabouts. I know the USGS are keeping a very close eye on that area.

 

[King of the Americas]

Mountians, as 'I' know them, are conic. Large base, getting more narrow at the top.

Bermuda's underwater structure isn't 'conic'. It has a hour glass form or shape, with a wide botom, narrow 'waist', and wide top. Situated atop an ancient volcano, scientists suggested that the island was formed by a volcanic spire, who's middle remained liquid, which allowed the 'top' to mushroom.

I have still yet to locate a graphic to demonstrate this but I am looking...

If Bermuda was formed this way, couldn't other islands have been also? And this IS the way Bermuda was formed, and how it 'sits', if it waist became unstable, couldn't it 'sink'...?

 

[Ixion]

New islands and coral shelf islands (such as the Maldives) I think would be the most susceptible to submersion. Volcanic shield islands generally grow very slowly, and are subject to tremors which could collapse lava chutes and once again submerge the newly formed island. For an example of a newly forming volcanic shield island in the South Pacific, check out New Island which shows that the sand pushed up from the ocean floor is very shallow and unstable.

Also island chains like the Maldives are formed on coral reefs and barely sit above sea level. The tsunami in 2004 temporarily submerged some of the islands, and whether or not you believe in global warming, the fact is that if the ice shelves in the arctic melt, then islands like this will be completely submerged.

 

[Correa Neto]

Mountians, as 'I' know them, are conic. Large base, getting more narrow at the top.

Bermuda's underwater structure isn't 'conic'. It has a hour glass form or shape, with a wide botom, narrow 'waist', and wide top. Situated atop an ancient volcano, scientists suggested that the island was formed by a volcanic spire, who's middle remained liquid, which allowed the 'top' to mushroom.

I have still yet to locate a graphic to demonstrate this but I am looking...

If Bermuda was formed this way, couldn't other islands have been also? And this IS the way Bermuda was formed, and how it 'sits', if it waist became unstable, couldn't it 'sink'...?

Sorry, but whoever created this idea is completely wrong.

Check
http://www.mantleplumes.org/P^4/P^4Chapters/VogtBermudaP4AcceptedMS.pdf.
http://www.coexploration.org/bbsr/coral/html/body_reef_formation.htm

Whoever created this idea has little if any understanding of what are carbobate shelves and/or diapirism.

 

[Hokulele]

KotA, I would take anything seen on the History Channel these days with a block of rock salt. Volcanic islands and their resulting atolls just aren't "hourglass" shaped, but roughly cone shaped like any other island. As others in this thread have mentioned, the life cycle of an atoll is very well understood, and Charles Darwin is often credited for his analysis and description of the process. There are many atoll chains in the Pacific (ring of fire and all that), and none of them display the properties you are describing. As an example of just how massive these can be, see the dozens of atolls and islets that make up the Marshall Islands.

http://www.rmiembassyus.org/Geography.htm

You can click on the various links at the bottom of this page to see maps of several of the atolls. The lagoon in the middle of Kwajalein is particularly impressive.

And for those discussing changes in an island's topography, this is an interesting article from the Hawai'i Volcano Observatory about what could and what could not happen on the Big Island due to volcanic activity there. Although, this page does state that the Big Island is sinking, mostly due to the lava adding weight to the island.

http://hvo.wr.usgs.gov/volcanowatch/2001/01_10_04.html

 

[Soapy Sam]

Sinking into the upper mantle, yes. If sea level remains constant, then it is sinking relative to that too. The point is, sea level does not remain constant for long- it goes up and down like a whore's drawers, on geological timescales- so any submergence of a landmass is far more likely due to sea level change than actual vertical movement of the land mass.
Exceptions on a human timescale would be new volcanoes- Surtsey or even Krakatoa for example. On long timescales, well, the Himalaya have certainly moved up relative to any arbitrary measure. Death valley has moved down. and so on.