Posted on 03/29/2002 4:55:12 PM PST by Lessismore
Seems to be quite a bit of sensationalizing going on.
On another note and more dramatic, my theory is that it did not 'sink', this city could have been built on the shoreline of a much reduced (water) level of the Gulf Of Mexico that was blocked off from the worlds oceans across Florida, The Bahamas and the Yucatan or some combination such as this during the last Ice Age. I will post a link to a map that will show the worlds oceans at a reduced water level of about 300 ft. Most scientists think the worlds oceans were reduced by 300-500ft worldwide during the last Ice Age.
Put your thinking cap on now. Imagine that the Gulf Of Mexico was blockaded from the world's oceans at the height of the Ice Age. The world's oceans would stabilize (water depth) at 300-500ft below present levels while the Gulf Of Mexico (now blockaded) would continue to dry out and then finally stablize at a level much below the worlds oceans during the Ice Age.
This 'underwater' city was built on dry land on the shore of the dessicated Gulf Of Mexico thousands of years ago. Once the ice from the Ice Age began to melt and the water levels of the worlds oceans began to rise, the rising water reached a level that would breech the blocade to the Gulf Of Mexico and cause a catastrophic flood (like the Black Sea) and anything on the shoreline would now be hundreds of feet underwater. I came up with this idea after reading about the Black Sea flood and realizing that a half mile is a long way for something to 'sink.'
There are probably ancient 'underwater' cities all over the globe.
DEFLATING A PARADIGM: BRAZIL'S PEDRA FURADA
The paradigm.
The New World was peopled from Asia by migration across the Bering Land Bridge about 12,000 years ago, or perhaps a wee earlier.
The Pedra Furada site has been dated at 50,000 BP by N. Guidon and her team of archeologists. This challenge to the dominant paradigm is powerful and unambiguous. Picking up the gauntlet, several more-conservative archeologists visited the Brazilian site and penned a blistering critique in Antiquity. (Ref. 1) Their major contention was that the 500+ supposedly human-made stone "artifacts" collected by Guidon's team are actually "geofacts"; that is, they were chipped and flaked naturally as rocks fell one upon the other from nearby cliffs. We discussed this problem in some detail in SF#105. Several other reservations about the Pedra Furada work are also offered in Ref. 1.
The reaction of Guidon et al to the Antiquity paper was thunderous to say the least. It revealed the depth of the chasm separating archeologists on the date of human occupation of the New World as well as internecine politics in archeology. (Ref. 2)
Guidon et al flung two serious charges at the authors of the first Antiquity paper: (1) They had their facts all wrong; and (2) Their objectivity was distorted by their loyalty to the aforestated paradigm. Not withholding any punches, N. Guidon and A.-M. Pessis entitled their opening broadside: "Falsehood or Untruth"! They wrote:
"The article by Meltzer et al (1994) is based on partial data and false information (highlighted below). Its battery of questions takes us by surprise; none of the three colleagues came up with these questions during the 1993 meeting -- mounted precisely to generate direct dialogue on the peopling of the America. We disagree with their statement, 'the comments on Pedra Furada are not offered lightly' (p. 696). The commentaries are worthless because they are based on partial and incorrect knowledge.
"We believe that the initial intention of the authors was different; they got carried away into an exercise in academic style, from a fragile scientific base of fragmentary data and with a skepticism born of a subjective conviction." (Ref. 2)
In the world of science, these are serious charges. Guidon and Pessis go on to dismiss each complaint made by Meltzer et al in Ref. 1. As for the "geofact" hypothesis, Guidon and Pessis point to two of the illustrations used by Meltzer et al, remarking:
"The artefact in their figures 9 & 10 has five successive parallel flakescars on the same edge. By the authors' hypothesis, it will have suffered the first when it fell; thereafter, four other pebbles fell on top of it, one beside the other, regularly, causing flake-scars with equal technical characteristics."
Sounds unlikely, doesn't it -- even if 50,000 years are allowed. And there are over 500 such "serial accidents."
Ref. 1. Meltzer, D.J., et al; "On a Pleistocene Human Occupation at Pedra Furada, Brazil," Antiquity, 68:695, 1994. Ref. 2. Guidon, N., et al; "Nature and Age of the Deposits in Pedra Furada, Brazil: Reply to Meltzer, Adovasio & Dillehay," Antiquity, 70:408, 1996.
Going Into The Water: A Survey Of Impact Events And The Coastal People Of South-East North America
You're welcome but I don't have a 'ping' list. (I never figured out how to do that and now everything else has changed, I'm really lost!)
It would help to know the precise coordinates of the "sunken city", but the popular accounts that I've seen don't provide that information.
I have done some rough calculations and simulations for questions concerning evaporation of the Gulf of Mexico and sea level.
Surface area of Gulf of Mexico: 15 million square km
Estimated depth evaporation rate: 1 meter/yr
Estimated volume evaporation rate for Gulf of Mexico: 1.7 trillion liters/hr
Normal volume flow of Mississippi R.: 23 billion liters/hr
An est. volume flow of Amazon R: 300 billion liters/hr
I have included flows of large rivers for comparison with the evaporation rate. So, for example, the flow of about 100 Mississippi Rivers are needed to compensate evaporation in the Gulf of Mexico. Only about 5 or 6 Amazon Rivers would be needed. It is stated that the Amazon flow represents about 20% of all the fresh water flowing into the oceans on earth. So given somehow that the Gulf of Mexico could be isolated from the oceans, I estimate it could take anywhere between 700 to 2100 years for the water level of the Gulf of Mexico to drop about 2000 ft due to evaporation, depending on the amount of water flowing from rivers, reduction of surface area, etc.
To isolate the Gulf of Mexico as it now stands seems to require essentially damming the lengths of the straight of Florida and the Yucatan channel. Each of these run about 200 kms shortest distance between land masses. BTW - this does not seem out of reach of immense human possibilities if we ever wanted to make a man-made dam:)
The depths of these I have been unable to determine exactly, but I estimate they could average anywhere between 2000 to 3500 ft. Is it possible that they are less, or that there is a path which is less, or perhaps there was smaller lengths due to since dissipated land mass?
This is all towards determining whether or not it could have been possible that the Gulf of Mexico was isolated or partially isolated enough so it could have a water level lower by approximately 2000 ft below today's sea level.
To get an idea of the competition between evaporation and inflow through ocean channels, e.g. through the straight of Florida, I have calculated some scenarios using a quasi-steady Bernoulli-like flow model. This allows consideration of the width and depth of channels connecting the Gulf of Mexico to the ocean with the Gulf of Mexico at a lower level than the ocean. This has assumed a drop at the channel.
1) Assume current effective channel width of 400 km, and try to maintain a difference of 2000 ft. The pressure is about 1000 psi. This is unsustainable from evaporation. It would take only about three days for the difference to decrease by 1000 ft.
2) Determine the maximum width of the channel and water level difference necessary to maintain an equilibrium with evaporation, ignoring additional inflow from rivers.etc:
Channel width Equilibrium difference in level ------------------
-------------------------
-------- 400 km .................. 41 cm
200 km .................. 65 cm
40 km ................... 1.9 m
4 km .................... 8.8 m
1 km .................... 22 m
0.5 km .................. 35 m
7 m ..................... 2000 ft
3) Given the width of the channel, determine the change of the level with time for a variety of initial levels. This allows the possibility to determine time dependant scenarios, e.g. given some catastrophic or otherwise sudden event leaving the gulf very low, could the rise to equilibrium have been slow enough to take a long time >100 yrs? Or given that the channel width was decreased by some event, how long would it take to drop the level? I have attached a series of red arrow flow graphs showing the result with certain inital conditions as lines. These graphs are of the difference between sea level and gulf level in units of centimeters on the vertical scale and units of hours on the horizontal scale. The difference between sea level and gulf level means that a positive increase on the graph represents a lowering of the relative level of the gulf. Each is titled according to the width of the channel in kilometers. Note that the scale of the axis does change from graph to graph.
The summary from graphs is essentially the gulf fills up pretty quickly away from equilibrium except for the smallest channel widths less than 4 km. The symmetry from above and below equilibrium is interesting and useful for analysis. An isolation event creating a channel 4km will take about 6 years to drop the gulf by half its equilibrium level of 8.8 meters below sea level. Even a 0.5 km channel will take only about 25 years to reach half its equilibrium value of 35 meters. A 50 meter channel takes about 100 yrs to drop halfway to its equilibrium drop of about 160 m. As shown by the fact that only a 7 meter wide channel can sustain 2000 ft indefinitely, the only way to have sustain such large diifferences in depths is to have a very narrow channel - or of course, no channel at all.
(Frankly, I was suprised to hear anymore about this subject but, they apparently were pretty excited about the prospect. This is just a small sampling of the correspondense on this subject. I did not include all the charts and graphs. This communication refers to the Gulf Of Mexico somewhat isolated but with a deep channel.)
I have done some rough calculations and simulations for questions concerning evaporation of the Gulf of Mexico and sea level.
Surface area of Gulf of Mexico: 15 million square km
Estimated depth evaporation rate: 1 meter/yr
Estimated volume evaporation rate for Gulf of Mexico: 1.7 trillion liters/hr
Normal volume flow of Mississippi R.: 23 billion liters/hr
An est. volume flow of Amazon R: 300 billion liters/hr
I have included flows of large rivers for comparison with the evaporation rate. So, for example, the flow of about 100 Mississippi Rivers are needed to compensate evaporation in the Gulf of Mexico. Only about 5 or 6 Amazon Rivers would be needed. It is stated that the Amazon flow represents about 20% of all the fresh water flowing into the oceans on earth. So given somehow that the Gulf of Mexico could be isolated from the oceans, I estimate it could take anywhere between 700 to 2100 years for the water level of the Gulf of Mexico to drop about 2000 ft due to evaporation, depending on the amount of water flowing from rivers, reduction of surface area, etc.
To isolate the Gulf of Mexico as it now stands seems to require essentially damming the lengths of the straight of Florida and the Yucatan channel. Each of these run about 200 kms shortest distance between land masses. BTW - this does not seem out of reach of immense human possibilities if we ever wanted to make a man-made dam:)
The depths of these I have been unable to determine exactly, but I estimate they could average anywhere between 2000 to 3500 ft. Is it possible that they are less, or that there is a path which is less, or perhaps there was smaller lengths due to since dissipated land mass?
This is all towards determining whether or not it could have been possible that the Gulf of Mexico was isolated or partially isolated enough so it could have a water level lower by approximately 2000 ft below today's sea level.
To get an idea of the competition between evaporation and inflow through ocean channels, e.g. through the straight of Florida, I have calculated some scenarios using a quasi-steady Bernoulli-like flow model. This allows consideration of the width and depth of channels connecting the Gulf of Mexico to the ocean with the Gulf of Mexico at a lower level than the ocean. This has assumed a drop at the channel.
1) Assume current effective channel width of 400 km, and try to maintain a difference of 2000 ft. The pressure is about 1000 psi. This is unsustainable from evaporation. It would take only about three days for the difference to decrease by 1000 ft.
2) Determine the maximum width of the channel and water level difference necessary to maintain an equilibrium with evaporation, ignoring additional inflow from rivers.etc:
Channel width Equilibrium difference in level ------------------
-------------------------
-------- 400 km .................. 41 cm
200 km .................. 65 cm
40 km ................... 1.9 m
4 km .................... 8.8 m
1 km .................... 22 m
0.5 km .................. 35 m
7 m ..................... 2000 ft
3) Given the width of the channel, determine the change of the level with time for a variety of initial levels. This allows the possibility to determine time dependant scenarios, e.g. given some catastrophic or otherwise sudden event leaving the gulf very low, could the rise to equilibrium have been slow enough to take a long time >100 yrs? Or given that the channel width was decreased by some event, how long would it take to drop the level? I have attached a series of red arrow flow graphs showing the result with certain inital conditions as lines. These graphs are of the difference between sea level and gulf level in units of centimeters on the vertical scale and units of hours on the horizontal scale. The difference between sea level and gulf level means that a positive increase on the graph represents a lowering of the relative level of the gulf. Each is titled according to the width of the channel in kilometers. Note that the scale of the axis does change from graph to graph.
The summary from graphs is essentially the gulf fills up pretty quickly away from equilibrium except for the smallest channel widths less than 4 km. The symmetry from above and below equilibrium is interesting and useful for analysis. An isolation event creating a channel 4km will take about 6 years to drop the gulf by half its equilibrium level of 8.8 meters below sea level. Even a 0.5 km channel will take only about 25 years to reach half its equilibrium value of 35 meters. A 50 meter channel takes about 100 yrs to drop halfway to its equilibrium drop of about 160 m. As shown by the fact that only a 7 meter wide channel can sustain 2000 ft indefinitely, the only way to have sustain such large diifferences in depths is to have a very narrow channel - or of course, no channel at all.
(Frankly, I was suprised to hear anymore about this subject but, they apparently were pretty excited about the prospect. This is just a small sampling of the correspondense on this subject. I did not include all the charts and graphs. This communication refers to the Gulf Of Mexico somewhat isolated but with a deep channel to the ocean.)
Figure 1 gives a topographic map of the sea floor in the Yucatan Straits. It is about 2000 meters deep.
Your calculations don't include an estimate of precipitation over the Gulf of Mexico. The net evaporation may be a lot smaller than 1 m/yr.
My instincts are that precipitation levels would have been much reduced during the Ice Age. I could not get the url to work.
Must have been the result of a conspiracy, then. ;-)
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