Scientists drilled down to the sea floor to collect coral samples. Photo: IODP
Posted on 03/30/2012 12:44:46 PM PDT by Red Badger
Coral off Tahiti has linked the collapse of massive ice sheets 14,600 years ago to a dramatic and rapid rise in global sea-levels of around 14 metres.
Previous research could not accurately date the sea-level rise but now an Aix-Marseille University-led team, including Oxford University scientists Alex Thomas and Gideon Henderson, has confirmed that the event occurred 14,650-14,310 years ago at the same time as a period of rapid climate change known as the Bølling warming.
The finding will help scientists currently modelling future climate change scenarios to factor in the dynamic behaviour of major ice sheets.
A report of the research is published in this week’s Nature.
"It is vital that we look into Earth’s geological past to understand rare but high impact events, such as the collapse of giant ice sheets that occurred 14,600 years ago," said Dr Alex Thomas of Oxford University’s Department of Earth Sciences, an author of the paper. "Our work gives a window onto an extreme event in which deglaciation coincided with a dramatic and rapid rise in global sea levels – an ancient ‘mega flood’. Sea level rose more than ten times more quickly than it is rising now! This is an excellent test bed for climate models: if they can reproduce this extraordinary event, it will improve confidence that they can also predict future change accurately."
During the Bølling warming high latitudes of the Northern hemisphere warmed as much as 15 degrees Celsius in a few tens of decades. The team has used dating evidence from Tahitian corals to constrain the sea level rise to within a period of 350 years, although the actual rise may well have occurred much more quickly and would have been distributed unevenly around the world’s shorelines.
Dr Thomas said: "The Tahitian coral is important because samples, thousands of years old, can be dated to within plus or minus 30 years. Because Tahiti is an ocean island, far away from major ice sheets, sea-level evidence from its coral reefs gives us close to the ‘magic’ average of sea levels across the globe, it is also subsiding into the ocean at a steady pace that we can easily adjust for."
The research is part of a large international consortium, the Integrated Ocean Drilling Program (IODP), and the coral samples were obtained by drilling down to the sea floor from a ship positioned off the coast of Tahiti.
What exactly caused the Bølling warming is a matter of intense debate: a leading theory is that the ocean’s circulation changed so that more heat was transported into Northern latitudes.
The new sea-level evidence suggests that a considerable portion of the water causing the sea-level rise at this time must have come from melting of the ice sheets in Antarctica, which sent a ‘pulse’ of freshwater around the globe. However, whether the freshwater pulse helped to warm the climate or was a result of an already warming world remains unclear.
The UK’s contribution to this research, and involvement in the IODP programme, was funded through the Natural and Environmental Research Council (NERC), and was supported by the Oxford Martin School.
A report of the research, ‘Ice-sheet collapse and sea-level rise at the Bølling warming 14,600 years ago’, is published in the journal Nature.
The team comprised researchers from Aix-Marseille University (France), Oxford University’s Department of Earth Sciences (UK), University of Tokyo (Japan), National Institute of Polar Research, Tokyo (Japan) and Institute of Biogeosciences, JAMSTEC, Yokosuka (Japan).
Scientists drilled down to the sea floor to collect coral samples. Photo: IODP
AGW Ping!............
Now how could there be a 15 degree Celsius rise in temperatures without all the evil people driving SUV’s and the like. It must have been woolly Mammoth farts. Yet another nail in the AGW coffin.
How does this Bolling period compare to the Noah’s ark period, where a theory is that a glacier or some other barrier broke and the Black Sea flooded?
How does one pronounce “Bølling”?
Calling Noah.
baw-ling
The real reason for this 'research'? To get you to believe in a computer-model that 'predicts' global-warming. Obviates the need to support their contentions with real evidence. Computer-models are the old physics 'thought experiements' applied to new 'scientific' imaginations. GIGO
Yeah, but I’m sure it was really only a “local” “mega-flood”, and not a global one. /[bible can’t be true because science says so]
I`ll take mine on the rocks, shaken not stirred.
You aren’t going to like this, but Noah’s Ark is part of a story. Of course, the story could have been inspired by real events, but I suspect that the flooding idea was more easily derived from the annual floods of the Tigris and Euphrates rivers than from an event involving the Black Sea.
Similar flood stories are found through the region of Mesopotamia. The best known is the Gilgamesh Epic, a popular story for thousands of years. Gilgamesh lived around 2500 BC. The best-known version of the Gilgamesh Epic is from about 649 BC. It is an etiological tale, with many smaller etiological stories within it.
One part is very much like the Noah story, which clearly borrows from it.
Now that you are, I fear, disturbed about what I am saying, please calm down and be reassured. The point of the story of Noah is not in the little incidentals: it is in the lesson, and what it says about God and Man. Gilgamesh Epic has almost no moral content. Noah’s story is, by contrast, all about ethics, and how God will deal with sinful man. It is written, of course, from the understanding of the ancient Hebrew people.
The delightful story of Noah says, basically, that God will not deal with the problem of sin merely by wiping out mankind, which (as the story clearly and intentionally illustrates) he very well could. That message is very profound, and I trust, true. Certainly I hope that it is true!
GIGO is right!
Some scientists become so enamored of their favorite scientific positions, they cannot accept evidence, no matter how cogent, that their cherished ‘belief’ isn’t true.
You are just being silly about a serious problem. The temperature rise was from all the CFC’s in the hairspray the woolly mammoths had to use to look good. Ever try to tame a woolly mammoth?
Wait a minute!
Noah’s GPS said he was somewhere around the Med around 6000 years ago.
This infidel information cannot stand! Off with someone’s head
If I remember correctly, the Scriptural text is not even clear it was a global flood. Hebrew “eretz” could mean the whole earth or just mean “the land”. So there have been arguments over whether the Flood was geographically universal (it flooded the whole world) or anthropologically universal (it just involved the area where all mankind was living at the time).
It would be a mark of impiety to bleed all the historicity out of the account, but it’s perfectly reasonable to recognize parallel traditions and to understand that there is more involved in the story than a bare accounting of facts.
when all the methane hydrates ignite as the seas warm,, it won’t matter much how the coral holds out.. and they say watch out for warming of the permafrost .. ;-] interesting post! Thanks!
Not disturbed at all.
I read some time back in Science News about evidence of flooding in the Black Sea at the end of the last ice age (?) and evidence that there were possibly ancient buildings or something near shore but now underwater. The speculation was that a cataclysmic event like a glacier melting or breaking off, or something, could have given rise to the Biblical Noah account as well as the other great flood stories in the area. It was supposed to have been maybe 10,000 years ago, and might be the earliest pre-history thing that humanity remembers.
Anyway, I thought that it might be interesting if that was roughly the same time period as the Tahitian coral findings.
I’m not proposing using the Bible as a history book or science book, in the way that modern scholars do history or science. The Bible is the love story of God and His people. Clearly, the spiritual point of Noah’s adventures has nothing to do with global temperatures. Nevertheless, the Bible has some intriguing hints and clues about the ancient physical world, so why not ponder them?
Bump for later Saturday reading
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