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ATLANTIS & the Atlantic Ocean

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Apollo
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« Reply #60 on: March 30, 2007, 11:44:12 am »

Bluehue,

Of course, you know that is incorrect. The first mention of the Atlantic comes from Herodotus, and the Romans are typically attributed with giving the Atlantic Ocean it's name.

The Pacific Ocean was named in more recent times, however, perhaps you're thinking of that.
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il mio va Piano, sono Asino ?


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« Reply #61 on: March 30, 2007, 12:29:00 pm »

YES, Apollo, THAT too,

 Cheesy By-the-way-  I am  Glad to make your aquintance!

 Cry indeed the Romans have re-named many parts of the World with pretentious names. The Ports of CADIZ/Gadeira & Cartagena were renamed by the Punicians only in 200 bc, by the colonist General Hasdrubal from Carthage.  after the second Punic War, in remembrance of the glorious past of Atlantis as, an originally  punician Capital in Araby.  The Cities: Cartage; Sidon &Tyrus were also colonies of Older Cities with the same name in South-Araby

Sidon comes from "ADEN"(= a word-corruption from:  Po-Sidon.) Tyrus comes from "TSUR"; Cartage comes from: "Ras-FARTAK" etc.

Before 200 bc the Atlantic names in Spain did not exist.
but the whisfull-thinking Atlantologists make it seem as if These fairly recent atlantean-names in classical geography were 10.000 years old!


But Plato only knew ONE Ocean in his lifetime and so did Herodotus this was named the MARE-ERYTRAEUM it's alternative name was "Indian-Ocean".  and THAT part which bordered the Atlantic mainland was called the Atlkantic-Ocean which is a misnomer for: "Atlantikoum-Pelagiou" meaning the GULF-of-ADEN

Others called it not an Ocean-Brance but a Sea-Strait.

The Mediaterranean likewise was sometimes named Mare Nostrum, the Egyptians named it the BIG -Blue-Sea and what WE call the RED-Sea was for the egyptians the GREEN-Sea.

So we have a problem here: The indian Ocean was originally Known as MARE-Erytraeum which means ofcourse the Wine-Dark SEA , and if the Arabs would have had their way, to day it would be named"{ Arab-"SEA".)

And the Atlantic-Ocean was originally known as:"Spanish-SEA"

Sincerely  Cry  "BlueHue"   Cry
« Last Edit: March 30, 2007, 12:42:46 pm by BlueHue » Report Spam   Logged

( Blue's)THEORY, locating"original" Atlantis( in Aden-Yemen.)
1: ATLANTIS =Fake=Latin name, original Greek: ATHE(=a Region in Aden)
2: Atlantic-OCEAN=Greek: RIVER-of-Atlas+also" Known "World-OCEAN(=Red-Sea)
3: Greek-obsolete-Numeral 'X' caused Plato's Atlantisdate:9000=900
dhill757
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« Reply #62 on: March 31, 2007, 02:36:08 pm »

From Riven:



Universalis Cosmographia Secundum Ptholomaei Traditionem et Americi Vespucii Alioru[m]que Lustrationes,
St. Di, 1507
 

Recognizing and Naming America


Martin Waldseemllers 1507 world map grew out of an ambitious project in St. Di, near Strasbourg, France, during the first decade of the sixteenth century, to document and update new geographic knowledge derived from the discoveries of the late fifteenth and the first years of the sixteenth centuries. Waldseemllers large world map was the most exciting product of that research effort, and included data gathered during Amerigo Vespuccis voyages of 15011502 to the New World. Waldseemller christened the new lands "America" in recognition of Vespucci s understanding that a new continent had been uncovered as a result of the voyages of Columbus and other explorers in the late fifteenth century. This is the only known surviving copy of the first printed edition of the map, which, it is believed, consisted of 1,000 copies.

Waldseemllers map supported Vespuccis revolutionary concept by portraying the New World as a separate continent, which until then was unknown to the Europeans. It was the first map, printed or manuscript, to depict clearly a separate Western Hemisphere, with the Pacific as a separate ocean. The map represented a huge leap forward in knowledge, recognizing the newly found American landmass and forever changing the European understanding of a world divided into only three partsEurope, Asia, and Africa.


Martin Waldseemller (14701521)
Universalis Cosmographia Secundum Ptholomaei Traditionem et Americi Vespucii Alioru[m]que Lustrationes, [St. Di], 1507
Facsimile made from original woodcut
Geography and Map Division, Library of Congress
 
http://www.loc.gov/rr/geogmap/waldexh.html
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« Reply #63 on: March 31, 2007, 02:42:30 pm »



Sinister grey bulk of Mt Fogo, which last erupted in 1995 (Photographer: Frances Linzee Gordon)

Cape Verde
History


The history of Cape Verde is dominated by three overriding facts: there were no people of any sort on the islands when the Portuguese first arrived; the environment has become increasingly fragile over the centuries, largely due to the impact of people and overgrazing; and it's farther from the African mainland and closer to the Americas than any other African country. It's hardly surprising, therefore, that Cape Verde developed along lines somewhat different from the rest of Africa.

When Portuguese mariners first landed in Cape Verde in 1456, the islands were barren of people but not of vegetation. Seeing the islands today, you find it hard to imagine that they were once sufficiently verde (green) to entice the Portuguese to return six years later to the island of So Tiago to found Ribeira Grande (now Cidade Velha). The Portuguese soon brought slaves from the West African coast to do the hard labour. The islands also became a convenient base for ships transporting slaves to Europe and the Americas.

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« Reply #64 on: March 31, 2007, 02:45:20 pm »



Environment

The Cape Verde islands are in the Atlantic Ocean, 620km (385mi) west of West Africa's coast at Mauritania. There are 10 major islands (9 of them inhabited) and 5 islets, all of volcanic origin and grouped into the Barlavento (Windward) group (Santo Anto, So Vicente, Santa Luzia, Ilheu Branco, Ilheu Raso, So Nicolau, Sal and Boa Vista) to the north and the Sotavento (Leeward) group (Maio, So Tiago, Fogo and Brava) to the south.

The interior of the main island, So Tiago, is mountainous, and Fogo has the islands' highest peak, Mt Fogo (2840m/9320ft). Fogo was rocked by a volcanic eruption in 1995; there have been seven such eruptions since 1760. Many of the islands are arid and hilly, and cultivation of the hillsides has caused widespread soil erosion. Santo Anto has the highest rainfall and tends to be much greener than the other islands.

Common plants in the islands include rhododendrons, the fire tree, dragon tree, marmulano, corn plant and the Florida Beauty dracaena.

Among the islands' most colourful fauna are its coral and fish, especially in the waters around Sal, where you'll see parrot fish, barracuda and moray eels. You might also spot blue and humpback whales, the narrow-snouted dolphin, harbour porpoise and loggerhead, green and hawksbill turtles. The Raza Island lark, Cape Verde petrel, brown booby, frigatebird, tropicbird and Cape Verde warbler are among the birds winging around the archipelago. Creepy crawlies include the Cape Verde skink and the giant Cape Verde gecko.

Cape Verde has the coolest temperatures of any country in West Africa. Daily highs range from 20C (68F) to around 29C (84F) from August to October, when there can also be rainstorms. Due to ocean currents, the sea is also considerably chillier than along the West African coast.




Area: 4,030 sq km
Population: 401,343
http://www.lonelyplanet.com/destinations/africa/cape_verde/environment.htm


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« Reply #65 on: March 31, 2007, 02:51:35 pm »




G = Great Pyramid

A = Angkor Wat

V = Anatom Island

E = Easter Island

X = Atlantis?


"For example, the midway point between the Great Pyramid and Machupicchu is in the North Atlantic Ocean, approximately one degree south of the Cape Verde Islands. This is also the midway point between Easter Island and the Indus Valley. Although the Cape Verde Islands were found to be uninhabited when they were rediscovered in 1460 A.D., maps and geographical descriptions for the past 2000 years have shown this location to be the home of ancient island civilizations, including maps showing this location to be the site of Atlantis. In Plato's account of Atlantis, there was a mountainous region north of the city. Are the higher elevations of those mountains now the Cape Verde Islands?
"The distance from the Great Pyramid to Easter Island is approximately 40% of the circumference of the Earth. The X in the diagram is halfway between the two, 20% each way. Machupicchu is halfway between the X in the diagram and Easter Island, 10% each way. The Distance from the Great Pyramid to Angkor Wat is approximately 20% of the circumference, and the Indus Valley is halfway between the two, 10% each way. The Distance from Easter Island to Angkor Wat is approximately 40% of the circumference, and Anatom Island is halfway between them, 20% each way. These sites are located in multiples of 10% of the circumference of the Earth, and particularly at 20% intervals. Although there are no islands near the location of the X in the diagram, it is interesting to note that the famous Piri Reis map shows a large island in this location, and the geology of recent core samples, taken from the ocean floor in this area, is of continental rather than oceanic type rock:


quote:
--------------------------------------------------------------------------------
Geological structure of the Strakhov fracture zone (equatorial segment of the Mid-Atlantic ridge)
G. B. Udintsev, A. F. Beresnev, V. M. Golod, A. V. Kol'tsova, N. A. Kurentsova, and M. V. Zakharov

Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow
G. V. Agapova


Institute of Geology, Russian Academy of Sciences, Moscow

L. P. Volokitina

P. P. Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow

V. G. Udintsev

Shmidt Institute of Earth Physics, Russian Academy of Sciences, Moscow

------------------------------------------------------------------------

Abstract

Geological-geophysical data obtained during cruises 7, 11, and 12 of R/V Akademic Nikolay Strakhov (1989-1991) within the international project EQUARIDGE in the region of Strakhov fracture zone (4oN) are presented. The trough of the fracture is interpreted as an open extension joint, a graben produced by stretching along the axis of the Mid-Atlantic Ridge. Bedrock studies showed that the typical mid-oceanic tholeiitic basalts occur within the narrow (60 nm wide) axial rift zone, whereas igneous rocks not typical to the ocean were found on the eastern and western flank plateaus. This allows us to suppose that a reworked relict continental-type basement of pre-Upper Jurassic age possibly exists beneath the flank plateaus, within the segment under discussion. The above data correspond to the hypothesis by E. Bonatti about a nonspreading nature of the basement of Mid-Atlantic Ridge within the Equatorial segment and the Strakhov fracture zone.

Figures 3, Tables 3, References 22, Pages 544-558
Received December 16, 1993


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« Reply #66 on: March 31, 2007, 03:01:02 pm »



Madeira

 The closest thing to an off-season on this flowering Atlantic island north of the Canaries and far nearer Africa than Portugal may be midsummer when the European regulars are home tending their own gardens and the cruise ships move on to the Aegean.

Just as the Gulf Stream keeps the temperature of the ocean mild (64-68F) and there is no true rainy season (they admit to brief intense showers in March, April and October), the winter low is 65 and the summer high, 85. In November when it's 40 and raining in London, 20 and dark in Stockholm, it's 75 and sunny in Madeira. Flying time from Lisbon is one and one-half hours.

The lush environment of Madeira might easily have been exploited and its blessings taken for granted, but such is not the case. This politically autonomous region of Portugal has taken a cue from its ecologically aware home country: protect and prosper. Two thirds of Madeira and its sister island Porto Santo are a Natural Park conservation area. Even its uninhabited outpost isles, the tiny Desertas and Selvagens, are kept as sanctuaries for seabirds and breeding grounds for seals.

More than 600 miles of narrow irrigation channels (called "levadas") were built to bring water from the mountains to where it was most needed. Footpaths run beside them creating a web of ideal hiking trails all across the island. Escorted hikes and group excursions are offered by local travel agencies and hotels, but individuals, couples and families can plan their own walks using maps and information sheets provided by the tourist office. Trails are coded 1 to 4, easy to difficult. Small inns and restored houses in rural areas cater to hikers.

The flora is so exotic it seems contrived. Anthurium; orchids; bird-of-paradise; variegated lilies; protea and other flowers usually seen only in florists (and priced by the stem) bloom voluntarily. The Botanical Gardens, originally the country estate of the Reid family who built Reid's Hotel in Funchal a century ago, has acres of gardens, a tropical bird section and an outdoor cafe. The orchid collection is at its best December to April. A dozen private gardens are also open to the public certain days and hours, while April is the month of the three-day flower festival in Funchal.

Some 68 plants including three varieties of orchids grow in Madeira but nowhere else, at least not in their natural environment. Another 42 also occur in the Azores, Canaries and Cape Verde (the total region is called Macaronesia), and still others brought here by accident or intent on trading vessels from Asia and Africa quickly adapted to the soil and climate.

Bananas, mangos, avocados, papaya, oranges, lemons, guavas, custard apples and passion fruit grow in terraced orchards and are for sale in Funchal's vast covered market or by the side of the road. Walnuts and chestnuts are so abundant they have their own festivals upcountry in summer. The great Madeira wines are aged in oak barrels from the United States since oak trees on the island are protected.

Wickerware is made from the nonendangered and plentiful willow, and the village of Camacha is well-off because of it. Incidentally, one of the more creative ways to descend a mountain is in a "Carro de Cesto," a two-person wicker basket on runners. The ride, referred to locally as a "sleigh ride," goes from Monte to Funchal and was originally a market shortcut.

Madeira was unpopulated when it was discovered in 1419 by Portuguese explorer Joao Goncalves Zarco. He had anchored at Porto Santo in a storm, and his sailors seeing Madeira under a cloud on the horizon concluded this was the end of the earth. Zarco returned with a less nervous crew the following year and reached a mountainous densely forested island he named Ilha da Madeira, Island of Wood. He was so taken with the place he stayed on as governor and colonizer. Except for some British occupation during the Napoleonic wars and Spanish sword-rattling, Portugal prevailed.




Like so many volcanic islands, Madeira is speculated to be the top of the mythical Atlantis. Only 36 miles long and 14 miles wide, its mountains rise from 16,500 feet below sea level to 6100 feet above, and 90% of the island is 600 feet or more. The volcanoes are long dormant, but the mild climate keeps the rocky escarpment tooth-sharp. There are waterfalls in the north; the world's second highest sea cliff in the south; and a green facade of rare trees everywhere. This type of primitive forest (the "laurisilva") covered all Europe in the tertiary era only to be decimated by advancing glaciers that never reached this far south. Madeira is the same latitude as Casablanca, a scant 400 miles east.

There are no beaches except on Porto Santo which has five miles of white sand. On Madeira seaside swimming pools circulate seawater, and swimmers move out directly into the ocean. Windsurfing, water-skiing, surfing, snorkeling and scuba diving are increasingly popular. Espada, the black deepwater swordfish, is on every menu, and fishing charters are available through the hotels or at the port.

Incidentally, the finest aquarium in Europe built on the Lisbon waterfront for Expo 98 is a permanent fixture on the mainland. Consider adding on a few days to see it and to visit the Algarve. This southern coast of Portugal not only has great golf, it is 70 percent nature reserve, Natural Park, and is a vital point in the wetlands network connecting Europe and Africa. The Algarve was recently awarded the Grand Prix at the Swiss Travel Meeting in Geneva for its active promotion of environment protection.

IF YOU GO: Casual is the rule on Madeira. The exception is Reid's Palace Hotel, Funchal, where the dining rooms require coat and tie, and afternoon tea on the terrace has been a dress-up event since the 1800s. Evenings and trips into the mountains require sweaters.

Getting There: Direct flights from the United States, Canada, London and European capitals.

Getting Around: Rental cars; public buses. Bicycling on flat Porto Santo. Roads are much improved in the last several years, but the local drivers are wild.

http://www.goodmoney.com/madeira.htm

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« Reply #67 on: March 31, 2007, 03:04:50 pm »





Atlantis - above the waves
traditions, theories, evidence and facts



--------------------------------------------------------------------------------


Evidence from the floor of the ocean

In a 1954 issue of Geological Society of America, Bulletin, Bruce Heezen and others reported on a seamount - an underwater mountain - that has been named Atlantis by geologists and is in the Atlantic Ocean. It has been found to have been an island about 12,000 years ago - exactly the time specified by Plato! This abstract is given:
The Atlantis, Cruiser, and Great Meteor seamounts rise from a broad ridge or plateau which extends from the Mid-Atlantic Ridge to 37N. 32W. southeast to Great Sea mount at 30N. 28W. The Atlantis Sea mount, briefly explored 1947 and 1948, was found by echo sounding and submarine photography to have a fairly flat bedrock summit area at about 180 fathoms covered in some cases by current-rippled sand. Its slopes are covered with sand or ooze symmetrically rippled at 400 fathoms and marked by slump features in 570 fathoms. A small piece of volcanic agglomerate was dredged from 400 fathoms on the north slope. About a ton of flat pteropod limestone cobbles was dredged from the summit area. One of the cobbles gave an apparent radiocarbon age of 12,000 years 900 (J.L. Kulp). The state of lithification of the limestone suggests that it may have been lithified under subaerial [i.e. above water, on land surface] conditions and that the sea mount may have been an island within the past 12,000 years. (Heezen, Bruce C., et al, "Flat-Topped Atlantis, Cruiser, And Great Meteor Sea Mounts" in Geological Society of America, Bulletin, 65:1261, 1954 (Protogonos issue 9))

In later studies, evidence was found for the remnants of a "sunken block of continent" in the middle of the Atlantic Ocean. An articlein New Scientist 1975 summarizes the result. (Anonymous, New Scientist,66:540, 1975)

Although they make no such fanciful claim from their results as to have discovered the mythical mid-Atlantic landmass, an international group of oceanographers has now convincingly confirmed preliminary findings that a sunken block of continent lies in the middle of the Atlantic Ocean. The discovery comes from analysing dredge samples taken along the line of the Vema offset fault, a long east-west fracture zone lying between Africa and South America close to latitude 11N.

The article describes the first report of "shallow-water limestone fragments" from the Vema Fracture in the Atlantic:

Four years ago two University of Miami workers, J. Honnorez and E. Bonatti, first reported the recovery of shallow-water limestone fragments from the Vema fracture zone. This limestone contained minerals indicative of a nearby granitic source unlikely to occur on the ocean floor. Neither water currents, nor more esoteric transport systems, could explain the presence of these rocks so far from the modern boundaries of the continents. The two researchers believed that, instead, the granitic grains must have been deposited close to their source.

Then the recent researchers are noted:

Now, with C. Emiliani of Miami, Paul Bronniman of the University of Geneva, M.A. Furrer of Esso Production Research, Begles, and A.A. Meyerhof, a consulting geologist from Tulsa, USA, they have carried out a more searching analysis of the dredge samples (Earth and Planetary Science Letters, vol. 26, p.Cool

Finally he notes the evidence for activity in less than 30 meters ofwater, and even some evidence for activity in soil.

The Limestones include traces of shallow-water fossils - foraminifera, green algae, bits of gastropods, and crab coprolites - implying formation in water, in one instance, less than 30 m deep. Furthermore, the limestones have been recrystallized from a high to low-magnesium form of calcite. Oxygen and carbon-isotope ratios prove conclusively that this process must have taken place subaerially [on land surface] "through the action of meteoric water enriched in light carbon while passing through a soil zone ..." A pitted limestone sample bears evidence of tidal action. Some 50 km east of the dredge site along the Vema fracture the team also recovered a thick-shelled, shallow-water, bivalve fossil from a depth of over 2000 m.

The coprolites in the sample indicate a Mesozoic age for the limestone which may well be the sedimentary capping on a residual continental block left behind as the [??] spread out into an ocean. The granitic minerals could thus have come from the bordering continents while the ocean was still in its infancy. Vertical movements made by the block appear to have raised it above sea level at some period during its history.

(from Unknown Earth: A Handbook of Geological Enigmas by William R. Corliss.)


http://www.atlantissource.com/home/forgotten_article.htm
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« Reply #68 on: March 31, 2007, 03:11:02 pm »

From Atalante:

Some early geographers said that the Atlantic Ocean was bigger than our modern definition. By their definition the syrtes of Africa belong in the Atlantic ocean.
They presumed that the 3 continents (Europe/Asia/Afric) were separated by "tongues" of the surrounding ocean, which reached into the land.

1. Before I demonstrate data which may affect the location of Atlantis, let me cite these geographers' viewpoint about how Africa and Asia are separated.

quote from: http://syrcom.cua.edu/Hugoye/Vol6No1/HV6N1Takahashi.html
70 The Gulf of Aden is in fact the entrance to the Red Sea, but is often counted by Islamic geographers as a separate branch of the Indian Ocean. The usual name in Arabic is al-khalj al-barbar derived from Barbar/Berbera on its shore, but the name bahr al-barbar is found in Brn, Tafhm 122.9 (pers. 168.1 dary-i barbar)

2. Likewize, the classical Greek geographers had consistently (and erroneously) claimed that the Caspian Sea was connected to the surrounding ocean on the east side of the Caspian. Thus the Caspian sea separates Asia from Europe.

3. Now once these two geographical
"postulates" are understood, it becomes obvious that those early geographers must have recognized a third "tongue" of the surrounding ocean, to separate the continents of Europe and Asia from each other.

I believe the work of "pseudo-Aristotle" was connected to this outlook. Here is an interesting quotation about the matter, written by one of history's greatest geographers. Please note that the western Mediteranean sea is called "this well-known sea which is called the OCEAN by many."

quote from: http://syrcom.cua.edu/Hugoye/Vol6No1/HV6N1Takahashi.html
citing Bar Hebraes:
But., Min. V.i.1: That sea which surrounds the whole earth like a single island is called the Atlantic. In the west a narrow mouth is open to it at the Stelae (STLS), or Pillars, of Hercules. Through it it enters the Habitable World as if into some harbour and forms this well-known sea which is called the Oceanus [sic] by many.17 ... V.i.2.: In the south of this sea there are two gulfs and in them are two islands called the Greater and Lesser Syrtes. In its northern (side) are three gulfs, the Sardinian (SDRWNYQWN cod. F, SRDWNYQWN ceteri), the Galatian (GLTYQWN cod. F) and the Adriatic (DRYNWS cod. F), and after these a slanting gulf called the Sicilian (SYQYLYQWN).

the corresponding quote from pseudo-Aristotle is:
Cf. De mundo syr. 139.16-21, 139.23-140.1 [< gr. 393a 16-21, 23-28]: That sea which is outside the whole Habitable World is called the Atlantic and the Oceanus. It also flows around us here. Because on the west a narrow mouth (fumo aliso) is open to it from the inside at what are called the Stelae (STLWS) of Hercules its flow proceeds into this sea by us, as if into some harbour, and thus widens out little by little here, spreading out until it embraces (lobek < perilambn) the large gulfs which adjoin each other. It is said first to widen out to the right after proceeding from the Stelae (STLS) of Hercules and is divided into two gulfs and passes the islands called the Syrtes, one of which they call the Greater Syrtes and the other the Lesser Syrtes. On the other, northern, side it does not widen out immediately in the same way, but makes there too three gulfs (cubbin),18 that called the Sardinian (SWRDWNYQWN), that called the Galatian (GLTYQWN) and the Great Adriatic (DRYS rabbo). After these is another slanting gulf which is called the Sicilian (SQYLYQWN).


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« Reply #69 on: March 31, 2007, 03:25:34 pm »



http://www.lostcity.washington.edu/

Scientists Seeking Secrets Of "Lost City"

The remarkable hydrothermal vent structures serendipitously discovered last December in the mid-Atlantic Ocean, including a massive 18-story vent taller than any seen before, are formed in a very different way than ocean-floor vents studied since the 1970s, according to findings published July 12 in the journal Nature. The circulation of fluids that forms this new class of hydrothermal vents apparently is driven by heat generated when seawater reacts with mantle rocks, not by volcanic heat.


No one has previously seen a field quite like this but Deborah Kelley, a University of Washington oceanographer and lead author of the Nature paper, says this kind of vent may be common on the seafloor. If so, scientists may have underestimated the extent of hydrothermal venting, the amount of heat and chemicals pouring into the world's oceans and the abundance of life that thrives in such conditions.

"Rarely does something like this come along that drives home how much we still have to learn about our own planet," Kelley says. "We need to shed our biases in some sense about what we think we already know."

The Lost City Field, named partly because it sits on the seafloor mountain Atlantis Massif, was discovered Dec. 4. The expedition was funded by the National Science Foundation and led by Scripps Institution of Oceanography's Donna Blackman, UW's Kelley and Duke University's Jeffrey Karson. Blackman and Karson are among the paper's co-authors.

Lost City is like other hydrothermal vent systems where seawater circulates beneath the seafloor gaining heat and chemicals until there is enough heat for the fluids to rise buoyantly and vent back into the ocean. As the warm fluids mix with cold seawater the chemicals separate from the vent fluids and solidify, sometimes piling up into impressive mounds, spires and chimneys of minerals.

It was immediately clear, however, that the Lost City Field was unlike other hydrothermal vent systems in a number of ways. First, there was the height attained by some of the structures the mighty 180-foot vent scientists named Poseidon compares to previously studied vents that mostly reach 80 feet or less. The new vents are nearly 100 percent carbonate, the same material as limestone in caves, and range in color from a beautiful clean white to cream or gray, in contrast to black smoker vents that are a darkly mottled mix of sulfide minerals. And perhaps the Lost City's most distinctive feature is that it is sitting on 1.5 million-year-old crust formed from mantle material.

"We did not realize that hydrothermal activity of this sort could be taking place on seafloor generated millions of years ago," says Margaret Leinen, assistant director for geosciences at the National Science Foundation.

Most previously known vents form along the youngest part of spreading "centers," areas where tectonic forces pull apart the seafloor and magma flows up into the space sometimes during volcanic eruption. Heat from the underlying magma chambers drives hydrothermal vent circulation and generates water temperatures as high as 400C.

Lost City is in a part of the ocean where magma chambers are present only rarely and volcanic eruptions happen perhaps every 5,000 to 20,000 years, compared to fast-spreading centers where eruptions may occur every five to 10 years. In the area of the Lost City, spreading and faulting during the last 1 million to 1.5 million years has stripped the mountain down to the underlying mantle rocks. Hydrothermal circulation appears to be driven by seawater that permeates into the deeply fractured surface and transforms olivine in the mantle rocks into a new mineral, serpentine, in a process called serpentinization.

The heat generated during serpentinization appears to drive hydrothermal circulation at the Lost City, Kelley says. The process produces low temperature fluids of 40 to 75C that are rich in methane and hydrogen.

Papers published in the early 1990s noted that methane-hydrogen signatures were common over slow- or ultra-slow-spreading centers like the Mid-Atlantic Ridge, where Lost City is. That led scientists to believe that venting was occurring, but there had been no example like the Lost City Field before now, Kelley says.

If the Nature paper is right about the forces driving hydrothermal circulation at the Lost City Field, Kelley says it's easy to imagine there could be many more such systems. Within a mere 50-mile radius of the Atlantis Massif are three similar mountains subject to the same fracturing, the same intrusion of seawater and perhaps the same reactions with mantle material. And those four represent only a tiny fraction of the potential sites along the 6,200 mile Mid-Atlantic Ridge, as well as the Indian ridges and the Arctic Ridge, also considered slow- and ultraslow-spreading centers.

Although large animals that typify other vent environments appear to be rare at Lost City, microbial life seems to thrive there. The microbial samples collected at Lost City show a community that is diverse and so dense in places that magnification reveals rocks so covered with microorganisms that one can't see the minerals, Kelley says. "These environments may host a significant and important amount of microbial life, if these systems prove to be common and operate for long periods on old ocean crust."

Other authors of the paper are Gretchen Fruh-Green of the Institute for Mineralogy and Petrology in Zurich; Pete Rivizzigno of Duke; David Butterfield, Marvin Lilley, Eric Olson, Mathew Schrenk, Kevin Roe and Geoff Lebon, all from the University of Washington or affiliated with the National Ocean and Atmospheric Administration; and the shipboard party on the expedition last December.



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« Reply #70 on: March 31, 2007, 03:27:14 pm »

Hydrothermal Vent Systems Could Have Persisted Millions Of Years, Incubated Life
Science Daily The staying power of seafloor hydrothermal vent systems like the bizarre Lost City vent field is one reason they also may have been incubators of Earth's earliest life, scientists report in a paper published in the July 25 issue of Science.


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Discovered just 2 years ago during a National Science Foundation-funded expedition in the mid-Atlantic Ocean, Lost City has the tallest vents ever seen the 18-story behemoth at the site dwarfs most vents elsewhere by at least 100 feet. Water is circulated through the vent field by heat from serpentinization, a chemical reaction between seawater and the mantle rock on which Lost City sits, rather than by heat from volcanic activity or magma, responsible for driving hydrothermal venting at sites scientists have been studying since the early 1970s.

If hydrothermal venting can occur without volcanism, it greatly increases the places on the seafloor of early Earth where microbial life could have started. It also means explorers may have more places than previously thought to look for microbial life in the universe.

Although the Lost City vent field is a youthful 30,000 years old, Lost City-type systems might be able to persist hundreds of thousands, possibly millions, of years, says lead author Gretchen Frh-Green of the Swiss Federal Institute of Technology and co-authors from the University of Washington, Duke University and National Atmospheric and Oceanic Administration. One can imagine how such stable, long-lived systems pumping out heat, minerals and organic compounds for millennia might improve the chances for life to spark and to be sustained until it could take hold, say these scientists.

"It's difficult to know if life might have started as a result of one or both kinds of venting," says Deborah Kelley, University of Washington oceanographer, "but chances are good that these systems were involved in sustaining life on and within the seafloor very early in Earth's history."

As far as longevity and stability, it's possible that black-smoker systems might last as long as 100,000 years but it's unlikely, Kelley says. That's because black-smoker systems typically form where new seafloor is being created, a process that even if a volcanic eruption doesn't bury a hydrothermal vent field in lava will eventually shove the seafloor bearing the vents away from the source of volcanic heat needed to power them.

Lost City is already nine miles from the nearest volcanically active spreading center and sits on 1.5 million-year-old crust. Seawater permeating deeply into the fractured surface of the mantle rocks transforms olivine into a new mineral, serpentine. The heat generated during this process is not as great as that found at volcanically active sites where fluids can reach 700 F but it is enough to power hydrothermal circulation and produce vent fluids of 105 to 170 F.

Tectonics, the movement of the Earth's great plates, contributes to the fracturing of the mantle rock. But a big reason this kind of system is so self-sustaining, the Science report says, is that fracturing also happens because rocks undergoing serpentinization increase in volume 20 percent to 40 percent. Kelley likens it to water seeping into tiny cracks in roads, then freezing and expanding to cause ruts and frost heaves in the pavement.

Scientists think many Lost City-type systems were possible on early Earth because so much of the mantle had yet to be skinned over with crust, putting it in contact with seawater and making serpentinization possible, Kelley says.

Lost City is the only vent field of its kind known today but scientists say more could exist. Within a 60-mile radius of Lost City are three similar mountains and there are other, potential sites along thousands of miles of ridges in the mid-Atlantic, Indian Ocean and Arctic.

Beyond Earth, peridotite the mantle material that reacts with seawater during serpentinization is abundant on all the terrestrial planets in our solar system, says Jeff Karson, Duke University professor. "Peridotite can be exposed by tectonic processes or by major cratering events. This means that Lost City-type venting could occur, or has occurred, in oceans on other planets, and such venting would have the potential to support microbial systems."

Lost City-type systems also may be conducive to life because their fluids are high pH and rich with organic compounds compared to black-smoker systems.

Black smokers get their name because it can appear as if smoke is billowing from the vents. What's actually being seen are dark minerals precipitating when scalding hot vent waters meet the icy-cold ocean depths. Water venting at Lost City, in comparison, is hot enough to shimmer but not "smoke." Because of the different chemistry, black-smoker vents are a darkly mottled mix of sulfide minerals whereas the Lost City vents are nearly 100 percent carbonate, the same material as limestone in caves, and range in colors from white to cream to gray.

The field, named Lost City in part because it sits on a seafloor mountain named the Atlantis Massif, was discovered Dec. 4, 2000, when scientists weren't even looking for hydrothermal vents.

"The discovery of the Lost City vent field is a wonderful example of serendipity in science studying one problem and discovering something totally new and unexpected," says David Epp, program director in NSF's marine geology and geophysics program. "The detailed work is just beginning and should change the way people think about vent systems."

This spring, the NSF funded the first major scientific expedition to Lost City since its discovery. Led by Kelley and Karson, the expedition is documented at: http://www.lostcity.washington.edu/

Other Science co-authors are the Swiss Federal Institute of Technology 's Stefano Bernasconi, University of Washington's Kristin Ludwig and Giora Proskurowski, and National Atmospheric and Oceanic Administration 's David Butterfield.

Note: This story has been adapted from a news release issued by University Of Washington.


http://www.sciencedaily.com/releases/2003/07/030725080845.htm
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« Reply #71 on: March 31, 2007, 03:40:19 pm »


Hydrothermal vent system unlike any seen before found in Atlantic

 




  A ledge or flange made of carbonate juts out from the side of a 160-foot chimney in the Lost City hydrothermal vent field. The chimney and flange are made of carbonate minerals and silica dissolved in 160 F fluids that flow out of the seafloor and then precipitate when the fluids hit the icy cold seawater. The flange is 1 meter across. (Photo credit: University of Washington)
 
 
A new hydrothermal vent field, which scientists have dubbed "The Lost City," was discovered Dec. 4 on an undersea mountain in the Atlantic Ocean. The unexpected discovery occurred at 30 degrees North on the Mid-Atlantic Ridge during an oceanographic cruise aboard the research vessel Atlantis.

A team of scientists led by Deborah Kelley from the University of Washington, Donna Blackman from the Scripps Institution of Oceanography and Jeff Karson of Duke University conducted the National Science Foundation-supported expedition.

"We thought that we had seen the entire spectrum of hydrothermal activity on the seafloor, but this major discovery reminds us that the ocean still has much to reveal, "says Margaret Leinen, NSF assistant director for geosciences.

"These structures, which tower 180 feet above the seafloor, are the largest hydrothermal chimneys of their kind ever observed," said Deborah Kelley, a University of Washington geologist and co-principal investigator on the cruise.

Most previously studied vents are less than 80 feet high, the tallest being a 135-foot vent dubbed Godzilla, on the seafloor off the Washington state coast. It toppled in half a few years ago.

"If this vent field was on land, it would be a national park," Duke University structural geologist Jeff Karson said of the new find. Karson, a second co-principal investigator, joined Kelley in the submersible Alvin on a dive to the site on Dec. 5.

Perhaps most surprising is that the venting structures are composed of carbonate minerals and silica, in contrast to most other mid-ocean ridge hot spring deposits, which are formed by iron and sulfur-based minerals. The low-temperature hydrothermal fluids may have unusual chemistries because they emanate from mantle rocks.





The top of this 18-story-tall chimney in the Lost City hydrothermal vent field is nearly 30 feet in diameter and is actively venting fluids. (Photo credit: University of Washington)
 
 Nothing like this submarine hydrothermal field has ever been previously observed, say the scientists. These events are unique, they believe, because they rest on one-million-year-old ocean crust formed tens of kilometers beneath the seafloor, and because of their incredible size. Dense macrofaunal communities such as clams, shrimps, mussels, and tube worms, which typify most other mid-ocean ridge hydrothermal environments, appear to be absent in this field. The Lost City Field was discovered unexpectedly while studying geological and hydrothermal processes that built an unusually tall, 12,000-foot-mountain at this site. In this area, deep mantle rocks called serpentinized peridotites, and rocks crystallized in subseafloor magma chambers, have been uplifted several miles from beneath the seafloor along large faults that expose them at the surface of the mountain.
"As so often happens, we were pursuing one set of questions concerning building of the mountain and we stumbled onto a very important new discovery," said Donna Blackman, a geophysicist from the Scripps Institution of Oceanography and chief scientist of the expedition. She added that "the venting towers are very spectacular and, although they bring up a whole new set of questions, we will learn about the evolution of the mountain itself as we study the vents carefully in the future."

 

 Observations using the submersible Alvin and deep-towed vehicle Argo, operated by Woods Hole Oceanographic Institution, show that the field hosts numerous active and inactive hydrothermal vents. The steep-sided, 180-foot-tall deposits are composed of multiple spires that reach 30 feet in width at their tops. They are commonly capped by white, feathery hydrothermal precipitates. The tops and sides of the massive edifices are awash in fluids that reach temperatures up to 160 degrees.
From the sides of the structures, abundant arrays of delicate, white flanges emerge. Similar to cave deposits, complex, intergrown stalagmites rise several meters above the flange roofs.

Underneath the flanges, trapped pools of warm fluid support dense mats of microbial communities that wave within the rising fluids. Downslope, hundreds of overlapping flanges form hydrothermal deposits reminiscent of hot spring deposits in Yellowstone National Park. During the Alvin dive, expedition leader Patrick Hickey collected rocks, fluids, and biological samples for shore-based analyses.

"By studying such environments, we may learn about ancient hydrothermal systems and the life that they support," suggested Kelley.






Cone-shaped pinnacles, about 20 feet can be seen, rise from a 160-foot-tall edifice in the Lost City hydrothermal vent field. White-colored chimneys are actively venting fluids in contrast to the beige-colored edifices that are no longer venting. (Photo credit: University of Washington)
 


Kelley, Blackman and Karson are at sea until Saturday, Dec. 16, and return to their home institutions from there.

The three principal scientists may be contacted aboard ship until Sat. Dec.16. (Note: e-mail is only sent and received three times a day.)
Donna Blackman
Debbie Kelley
Jeff Karson

Expedition web site:
http://earthguide.ucsd.edu/mar

 www.washington.edu/.../12-00archive/k121200.html
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« Reply #72 on: March 31, 2007, 03:46:09 pm »



The Atlantic Ocean is the second-largest ocean, covering approximately one-fifth of the Earth's surface. The ocean's name, derived from Greek mythology, means the "Sea of Atlas." The oldest known mention of this name is contained in The Histories of Herodotus around 450 BC (I 202).

This ocean occupies an elongated, S-shaped basin extending in a north-south direction and is divided into the North Atlantic and South Atlantic by Equatorial Counter Currents at about 8 North latitude. Bounded by the Americas on the west and Europe and Africa on the east, the Atlantic is a component of the all-encompassing World Ocean, linked to the Pacific Ocean by the Arctic Ocean on the north and the Drake Passage on the south. A man-made connection between the Atlantic and Pacific is provided by the Panama Canal. On the east, the dividing line between the Atlantic and the Indian Ocean is the 20 East meridian, running south from Cape Agulhas to Antarctica. The Atlantic is separated from the Arctic by a line from Greenland to northwestern Iceland and then from northeastern Iceland to the southernmost tip of Spitsbergen and then to North Cape in northern Norway.[1]

While some authorities show the Atlantic Ocean extending south to Antarctica, others show it as bounded to the south by the Southern Ocean.

Covering approximately 20% of Earth's surface, the Atlantic Ocean is second only to the Pacific in size. With its adjacent seas it occupies an area of about 106,400,000 square kilometers (41,100,000 sq mi); without them, it has an area of 82,400,000 square kilometers (31,800,000 sq mi). The land area that drains into the Atlantic is four times that of either the Pacific or Indian oceans. The volume of the Atlantic Ocean with its adjacent seas is 354,700,000 cubic kilometers (85,100,000 cu mi) and without them 323,600,000 cubic kilometers (77,640,000 cu mi).

The average depths of the Atlantic, with its adjacent seas, is 3,338 meters (10,932 ft); without them it is 3,926 meters (12,881 ft). The greatest depth, 8,605 meters (28,232 ft), is in the Puerto Rico Trench. The width of the Atlantic varies from 2,848 kilometers (1,770 mi) between Brazil and Liberia to about 4,830 kilometers (3,000 mi) between the United States and northern Africa.

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« Reply #73 on: March 31, 2007, 03:47:10 pm »

Ocean bottom

The principal feature of the bottom bathymetry (terrain) of the Atlantic Ocean is a submarine mountain range called the Mid-Atlantic Ridge. It extends from Iceland in the north to approximately 58 South latitude, reaching a maximum width of about 1,600 kilometers (1,000 mi). A great rift valley also extends along the ridge over most of its length. The depth of water over the ridge is less than 2,700 m (8,900 ft) in most places, and several mountain peaks rise above the water and form islands. The South Atlantic Ocean has an additional submarine ridge, the Walvis Ridge.

The Mid-Atlantic Ridge separates the Atlantic Ocean into two large troughs with depths averaging between 3,700 and 5,500 metres (12,000 and 18,000 ft). Transverse ridges running between the continents and the Mid-Atlantic Ridge divide the ocean floor into numerous basins. Some of the larger basins are the Guiana, North American, Cape Verde, and Canaries basins in the North Atlantic. The largest South Atlantic basins are the Angola, Cape, Argentina, and Brazil basins.

The deep ocean floor is thought to be fairly flat, although numerous seamounts and some guyots exist. Several deeps or trenches are also found on the ocean floor. The Puerto Rico Trench, in the North Atlantic, is the deepest. The Laurentian Abyss is found off the eastern coast of Canada. In the South Atlantic, the South Sandwich Trench reaches a depth of 8,428 metres (27,651 ft). A third major trench, the Romanche Trench, is located near the equator and reaches a depth of about 7,454 meters (24,455 ft). The shelves along the margins of the continents constitute about 11% of the bottom topography. Several deep channels cut across the continental rise.

Ocean sediments are composed of terrigenous, pelagic, and authigenic material. Terrigenous deposits consist of sand, mud, and rock particles formed by erosion, weathering, and volcanic activity on land and then washed to sea. These materials are found mostly on the continental shelves and are thickest off the mouths of large rivers or off desert coasts. Pelagic deposits, which contain the remains of organisms that sink to the ocean floor, include red clays and Globigerina, pteropod, and siliceous oozes. Covering most of the ocean floor and ranging in thickness from 60 to 3,300 meters (200 to 11,000 ft), they are thickest in the convergence belts and in the zones of upwelling. Authigenic deposits consist of such materials as manganese nodules. They occur where sedimentation proceeds slowly or where currents sort the deposits.

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« Reply #74 on: March 31, 2007, 03:48:29 pm »



The Atlantic Ocean as seen from the west coast of Ireland on a fair day

Water characteristics
 
The Atlantic Ocean as seen from the west coast of Ireland on a fair dayOn average, the Atlantic is the saltiest of the world's major oceans; the salinity of the surface waters in the open ocean ranges from 33 to 37 parts per thousand (3.3 - 3.7%) by mass and varies with latitude and season. Surface salinity values are influenced by evaporation, precipitation, river inflow, and melting of sea ice. Although the minimum salinity values are found just north of the equator (because of heavy tropical rainfall), in general the lowest values are in the high latitudes and along coasts where large rivers flow into the ocean. Maximum salinity values occur at about 25 north and south of the equator, in subtropical regions with low rainfall and high evaporation.

Surface water temperatures, which vary with latitude, current systems, and season and reflect the latitudinal distribution of solar energy, range from less than −2 C to 29 C (28 F to 84 F). Maximum temperatures occur north of the equator, and minimum values are found in the polar regions. In the middle latitudes, the area of maximum temperature variations, values may vary by 7 C to 8 C (13F to 14F).

The Atlantic Ocean consists of four major water masses. The North and South Atlantic central waters constitute the surface waters. The sub-Antarctic intermediate water extends to depths of 1,000 meters (3,300 ft). The North Atlantic Deep Water reaches depths of as much as 4,000 meters (13,200 ft). The Antarctic Bottom Water occupies ocean basins at depths greater than 4,000 meters (13,200 ft).

Within the North Atlantic, ocean currents isolate a large elongated body of water known as the Sargasso Sea, in which the salinity is noticeably higher than average. The Sargasso Sea contains large amounts of seaweed and is also the spawning ground for both the European eel and the American eel.

Because of the Coriolis effect, water in the North Atlantic circulates in a clockwise direction, whereas water circulation in the South Atlantic is counter-clockwise. The south tides in the Atlantic Ocean are semi-diurnal; that is, two high tides occur during each 24 lunar hours. The tides are a general wave that moves from south to north. In latitudes above 40 North some east-west oscillation occurs.

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