Monday, October 10, 2016

The place furthest from land is known as Point Nemo

 Wanna find Point Nemo? Look here
© / Matea Zlatkovic

From BBC by Ella Davies

Where do you go to get away from it all?
When the stress of everyday life pushes you to search for the most remote point on Earth, you might be surprised to learn there are actually a few to choose from.
But if you have decent sea legs, nothing beats the furthest point from land, also known as the "oceanic pole of inaccessibility".

Since its official title is a bit of a mouthful, it has been nicknamed Point Nemo, after author Jules Verne's famous seafaring anti-hero Captain Nemo.
The name means "no-one" in Latin which is fitting for a place so rarely visited by man.
Point Nemo is located over 1,000 miles (1,600km) equidistantly from the coasts of three far-flung islands. Ducie Island (one of the Pitcairn islands) is to the north, Motu Nui (of the Easter Island chain) is to the north-east and Maher Island (off the coast of Antarctica) is to the south.
It is a rather peculiar place.

Experts had long discussed the geographical conundrum of finding the middle of the ocean, but it took modern technology to provide a full solution.
The oceanic pole of inaccessibility was officially discovered in 1992 by survey engineer Hrvoje Lukatela.
Instead of launching an expedition, Lukatela stayed on dry land and calculated the point's location using specialist computer software.
Rather than simply putting a pin in a flat projection of the Earth, the software incorporated the planet's ellipsoid shape for maximum accuracy.
It seems unlikely that the point will move significantly within the foreseeable future.
"The location of three equilateral points is quite unique, and there are no other points on the Earth's surface that could conceivably replace any one of those," says Lukatela.
It is possible that better measurements, or coastal erosion, would shift the location of Point Nemo, "but only in the order of metres".
Point Nemo is so far from land, the nearest humans are often astronauts.
The International Space Station orbits the Earth at a maximum of 258 miles (416km).
Meanwhile the nearest inhabited landmass to Point Nemo is over 1,670 miles (2,700km) away.

 The Mir space station, before it crashed into the Pacific (Credit: NASA Photo/Alamy)

In fact the whole region around Point Nemo is well known to space agencies.
The area is officially known to space agencies as the "South Pacific Ocean Uninhabited Area". In particular, the Russian, European and Japanese space agencies have long used it as a dumping ground, because it is the point on the planet with the fewest human inhabitants and the quietest shipping routes.
Over a hundred decommissioned spacecraft are thought to now occupy this "spacecraft cemetery", from satellites and cargo ships to the defunct space station Mir.

Rather than single monuments to the history of space travel, the remains are spread across the ocean floor in bits, says space archaeologist Alice Gorman of Flinders University in Adelaide, Australia.
"Spacecraft do not survive atmospheric re-entry whole," says Gorman. "Most of them burn up in the fierce heat. The most common components to survive are fuel tanks and pressure vehicles, which are part of the fuel system. These are generally made of titanium alloys or stainless steel, often encased in complex carbon fibres, which are resistant to high temperatures."
While smaller fragments burn up in the atmosphere, leaving nothing but an impressive light show, Gorman says the larger parts of the 143-tonne Mir were reputed to have washed up on Fijian beaches, while the rest sank to the ocean depths.
"Like shipwrecks, they create habitats that will be colonised by anything and everything that lives at that depth," says Gorman.
"Unless there is residual fuel that leaks out, there should not be a hazard to aquatic life."
Rumours have long swirled about what might live at Point Nemo.

Artist's impression of Cthulhu. It is best not to look
(Credit: Geo Images/Alamy)

Despite writing 66 years before its discovery, science fiction author HP Lovecraft chose a site eerily close to the oceanic pole of inaccessibility for R'lyeh, the home of his legendary tentacle-faced creature Cthulhu.
In 1997, oceanographers recorded a mysterious noise less than 1,240 miles (2,000km) east of Point Nemo.
This led to a great deal of excitement, and a fair bit of trepidation.
The sound, dubbed "the Bloop", was louder than even a blue whale – leading to speculation that it was made by some unknown sea monster.
However, the Bloop has since been confirmed to be the sound of ice by the U.S. National Oceanic and Atmospheric Administration.
When large icebergs crack and fracture, they generate powerful, ultra-low-frequency sounds. Subsequent recordings of known icequakes have shared similarities with the Bloop.

So if Point Nemo is not really home to an octopus-man-dragon, what exactly does live there? According to oceanographer Steven D'Hondt of the University of Rhode Island in Narragansett, possibly not much.
This is because the oceanic point of inaccessibility sits within the South Pacific Gyre. This is a massive rotating ocean current: bound east and west by the continents of South America and Australia, north by the equator, and south by the strong Antarctic Circumpolar Current.

 no more info the Google Maps today....
(2014 printscreen)

The waters within the gyre are stable, with a surface temperature of 5.8C (42F) at Point Nemo according to data from NASA satellites.
The rotating current blocks cooler, nutrient-rich water from coming in.
What's more, because the region is so isolated from land masses, the wind does not carry much organic matter.
As a result, there is little to feed anything.
With no material falling from above as "marine snow", the seafloor is also lifeless.
D'Hondt describes it as "the least biologically active region of the world ocean."
Still, there are a few exceptional points where unique creatures can survive.

Point Nemo is near the southern end of the East Pacific Rise, a submarine line of volcanic activity that stretches up to the Gulf of California.
It marks the boundary of the Pacific and Nazca tectonic plates, which are gradually moving apart. Magma wells up in the gap between the plates, creating hydrothermal vents that blast out hot water and minerals.

It is an extreme environment, but bacteria thrive here, gaining their energy from chemicals released by the eruptions. In turn, the bacteria sustain larger creatures.
These include the "yeti crab", which was first observed in 2005 and named for its hairy appearance.
There is still much to be discovered in these depths, but its remoteness makes Point Nemo an expensive and challenging destination for research.
Apart from the occasional round-the-world yacht race, there are hardly any visitors.
That means it is unlikely to pop up on your social media, so you have to use your imagination to picture it.
"On a calm day, the sea surface in the heart of the South Pacific Gyre is simply beautiful – clear cornflower blue, with a violet tone – because it contains so little particulate matter and so little living material," says D'Hondt.
Or it would be, if it were not for littering.

When the virtual band Gorillaz released their 2010 album Plastic Beach, they created a fictional backstory: supposedly the music had been recorded at a recording studio built on marine debris at Point Nemo.
This is not as entirely far-fetched as it might sound. A study published in 2013 confirmed that there is a garbage patch within the South Pacific Gyre.
The biggest accumulation of waste was at the centre, around 1,550 miles (2,500km) north-east of Point Nemo.
The garbage is mainly plastic waste like polystyrene, film, fishing line, fragments and pellets washed from ships and coastlines.
The rotating current traps the trash, breaking it down into tiny pieces.
Biologists believe the rubbish could could throw the ecosystem out of balance by helping some species proliferate while others suffer.
Even in the most remote spot on the planet, it seems there is no escaping humanity's wasteful habits.

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