"All the World's a Stage We Pass Through" R. Ayana

Showing posts with label Atlantic Current. Show all posts
Showing posts with label Atlantic Current. Show all posts

Thursday, 13 January 2011

Mega-flood triggered Europe's last big freeze

Mega-flood triggered Europe's last big freeze
Global warming could plunge us into the cold again

Europe was plunged into a mini ice age 13,000 years ago after global warming caused a mega-flood, geologists said today.
Mark Bateman from the University of Sheffield, said a catastrophic flood was caused when an ice sheet in the U.S melted causing a huge amount of freshwater to be dumped into the Arctic Ocean.
This led to the shutting down of the Gulf Stream ocean circulation pattern that brings warmth to Europe.
lake graphic
A huge lake (pictured), the size of the UK, dumped fresh water into the Arctic Ocean around 13,000 years ago

'We're talking about a lake the size of the UK emptying very quickly,' Dr Bateman said.
'We don't know the exact period of time but we're talking about a catastrophic flood.'
The finding has confirmed past theories about the likely cause of a sudden cooling period called the Younger Dryas when temperatures in Europe, similar to today, quickly returned to ice age conditions. The cooling lasted for about 1,400 years.
'Our research shows that if you put a large volume of fresh water into the North Atlantic in a very short space of time, this is what happens,' Dr Bateman said.
His team's work is published in the latest issue of the journal Nature.
The Gulf Stream acts like a conveyer belt by bringing warm water from the tropics to Europe while cold salty water sinks to the depths in the far north. This 'overturning' circulation draws in yet more warm water from the south.

ice
The last of winter sea ice in Liverpool Bay and exposed cliff sediment at the MacKenzie Delta in Arctic Canada. Scientists fear global warming could cause another massive flood leading to a big freeze

Climate scientists fear rapid global warming could trigger a sharp increase in the amount of meltwater from Greenland.
This surge in freshwater could trigger a tipping point that overwhelms the Gulf Stream, shutting it down and likely plunging Europe into another deep freeze.
 Dr Bateman and his team confirmed the path of the floodwaters from Lake Agassiz that covered part of what is now Canada and the northern United States. The lake had formed in front of the ice-sheet that once covered a large part of North America.
Scientists had previously guessed that a giant flood unleashed from the lake probably caused the Younger Dryas cooling but couldn't confirm the route of the floodwaters.
research team
A research team log sediments in a cliff exposure at Liverpool Bay, Northwest Territory, Arctic Canada. They said a massive flood caused the Gulf Stream to shut down 13,000 years ago.

Dr Bateman found that the waters flowed down the Mackenzie River, Canada's longest, rather than the Saint Lawrence Seaway that had previously seemed the most likely route.
Studying sediments from cliff sections along the river delta, he said the evidence spanned a large area at many altitudes. This could only be explained by a mega-flood from Lake Agassiz.
Dating of the sediments helped the team pin down the date of the flooding, showing that it occurred right at the start of the Younger Dryas.
Satellite observations and computer models by scientists have shown that the Greenland ice sheet is melting at an accelerating rate, dumping large amounts of ice and meltwater into the North Atlantic.
A study published in the journal Science last November said recent summers further accelerated Greenland's mass loss to the equivalent of 273 cubic kilometers of water per year in the period 2006-2008.

 

And see
  • The day the Earth froze: An hour-long storm started a mini ice age, say scientists  - http://newilluminati.blog-city.com/ the_day_the_earth_froze_an_hourlong_storm_started_a_mini_i.htm

For further enlightenment see –

The Her(m)etic Hermit - http://hermetic.blog.com


This material is published under Creative Commons Copyright (unless an individual item is declared otherwise by copyright holder) – reproduction for non-profit use is permitted & encouraged, if you give attribution to the work & author - and please include a (preferably active) link to the original along with this notice. Feel free to make non-commercial hard (printed) or software copies or mirror sites - you never know how long something will stay glued to the web – but remember attribution! If you like what you see, please send a tiny donation or leave a comment – and thanks for reading this far…

From the New Illuminati – http://nexusilluminati.blogspot.com

Tuesday, 3 January 2006

Key Atlantic Current Slowing

Key Atlantic Current Slowing
Long-forecast result of warming may portend chill for Northern Europe




The Atlantic Conveyor, a life-giving ocean current that keeps Northern Europe warm, is slowing down, scientists said Wednesday.

If the 30 percent slowdown seen over the past 12 years is not just a blip, temperatures in Northern Europe could drop significantly, despite global warming, they added.

Scientists have long forecast that the Atlantic Conveyor that carries warm surface water north and cold deep water back to the equator could break down because of global warming.

According to the theory, rising air temperatures cause ice caps to melt, making the water less salty and therefore less dense so it can’t sink and flow back south.


First flesh on theory’s bones

The scientists said this was the first time that observations had put flesh on the bones of the theory.

“This is the first time we have observed a change in the current on a human time scale,” oceanographer Harry Bryden said, noting that the current had completely shut down during the ice ages.

But he said the latest figures were far from proving a trend and that constant and long-term monitoring was needed.

“It is like a radiator heating the atmosphere and is too important to leave to periodic observations,” Bryden told a news conference to flesh out a paper he co-authored in the science journal Nature.

The Hadley Center for Climate Prediction and Research has calculated that if the current stopped, temperatures in northern Europe could drop by up to 6 degrees centigrade in 20 years.

The latest figures, collated last year, are from a string of monitoring devices at various depths in the Atlantic from Morocco to Miami.

It was the fifth snapshot since 1957 taken in the same area of the temperatures and currents in shallow, mid and deep ocean.


Major shift in the flow

While measurements in 1981 and 1992 had shown little change, those in 1998 and 2004 had shown a major shift, with less of the warming Gulf Stream getting up to Greenland and less of the cold, deep returning current coming back.

The so-called Atlantic Meridional Overturning Current is known as the Atlantic Conveyor, of which the Gulf Stream is the surface component.

“This is tantalizing evidence that there may be a large change in ocean circulation under way that paradoxically could cause regional cooling,” said Phil Newton of Britain’s independent Natural Environment Research Council (NERC).

However, the scientists stressed that they could not be completely sure what was driving the change or how it might alter or be compensated for by winds that pick up the radiated heat and circulate it.



Copyright 2006 Reuters Limited. All rights reserved.


     http://www.sciencedaily.com/images/2004/04/040422222835.jpg

-         R. Ayana




For further enlightenment see –

The Her(m)etic Hermit - http://hermetic.blog.com


This material is published under Creative Commons Copyright – reproduction for non-profit use is permitted & encouraged, if you give attribution to the work & author - and please include a (preferably active) link to the original along with this notice. Feel free to make non-commercial hard (printed) or software copies or mirror sites - you never know how long something will stay glued to the web – but remember attribution! If you like what you see, please send a tiny donation or leave a comment – and thanks for reading this far…

From the New Illuminati – http://nexusilluminati.blogspot.com