Evidence For Noah's Flood?

This article just came out in Current Biology. What seems quite interesting
is the date of the mangrove forest found beneath the great barrier reef.
Any comments from geologists? What do you make of this and could it have
anything to do with Noah's flood?

Josh

Feature

New studies raise global warming fears

Nigel Williams

Available online 28 March 2005.

Gradual increases in global temperature may not lead to gradual changes in
climate. Nigel Williams reports on new studies that suggest previous climate
changes could have been more dramatic and polar environments may be
particularly at risk.

While researchers are developing increasingly sophisticated models of
potential climate change, few are predicting dramatic and sudden changes.
But researchers at the Australian Institute of Marine Science (AIMS) have
opened a window into the past that suggests dramatic change.

Scientists from the institute have uncovered ancient mangrove forests buried
beneath the Great Barrier Reef while carrying out research into a quite
different issue.

(259K)

Hidden secrets: Parts of the Great Barrier Reef off Australia appear to have
developed over rapidly submerged mangrove swamps after the last Ice Age,
raising fears that climate change may occur more rapidly than some current
models of contemporary global warming suggest. (Picture: Oxford Scientific
Films.)

One of the team, Dan Alongi, said that the expedition was surveying the
impact of nutrients on coastal inshore areas when scientists unearthed
mangrove forests in old river channels they believe may have run for
30kilometres to the edge of the continental shelf.

Researchers have long theorised that the sea level rose very gradually over
several thousand years, but these remnant mangrove forests tell another
story. While it was previously known that relic river beds exist beneath the
Great Barrier Reef, formed 9,000 years ago when the sea level was lower than
the continental shelf, their significance was never studied.

“When we took the first samples it was difficult to believe... we stood
amazed wondering what exactly we were dealing with. We thought it was
cyclone debris, but it was far too deep to be a modern event,” said Alongi.

The researchers took core samples from one to two metres of sediment and
found remnant mangrove 70 centimetres below the surface of the present
seafloor.

These core samples of mud are an evolutionary time frame. The evidence will
help to establish the state of the reef and nutrient sediment information as
it existed prior to human activity.

Alongi said the mangroves were incredibly well preserved, a fact most likely
attributed to the antibiotic properties in the concentrated tannins. “The
cores still have the characteristic smell of tannins, that’s why we thought
they were young.

“Within the cores were intact root systems and parts of trees including
twigs and branches that radiocarbon dating put between 8,550 and 8,740 years
of age.

“There’s such an abrupt change in core composition from mud-like substance
to intact mangrove branches… from the modern to the ancient, that it
suggests a large climate change happened,” said Alongi.

“This sharp boundary between these ancient mangroves and the overlying
modern mud can tell us something fundamental about how quickly the water
rose over time.”

Alongi estimates that the shift in sea level occurred over a geologically
short time-span, from a few centuries or even decades. Research now planned
with fellow AIMS scientists will help to paint a more accurate picture of
this timeframe, and investigate the concentration of background
radionuclides in the top layers of sediment. These measurements will help
pinpoint the period over which the sea level rose.

“Knowing how rapidly the seascape changed in the past helps us predict
future changes with global warming,” said Alongi.

The source of the deluge is not clear but there are growing suspicions that
Antarctica may have had a key role. Only five years ago the scientists on
the UN’s Intergovernmental Panel on Climate Change were confident that
Antarctica was a ‘slumbering giant’and its vast ice sheets so cold that they
would not begin to melt for centuries, even if the climate changed
elsewhere. But a conference held in London last month was told ‘the giant is
awakening’, and areas of the ice-bound continent are melting, causing faster
sea-level rise than expected.

But for western Europe and North America, the most worrying finding revealed
at the conference was the potential collapse of the sea current known as the
Gulf Stream, called the Atlantic thermohaline circulation. The melting of
Greenland and Arctic ice and additional freshwater from rainfall is
threatening to shut down the current. Mike Schlesinger, from the climate
research group at the University of Illinois, said a 3°C rise in temperature
this century, which is within current models, would lead to a 45per cent
chance of the current halting by the end of the century and a 70per cent
chance by 2200.

The current, which carries billions of watts of heat from the tropics to the
north Atlantic is known to be weakening, but the chance of it being switched
off completely by climate change was previously considered remote.

And the first evidence of human-produced global warming in the oceans has
been found, thanks to a computer analysis of seven million temperature
readings taken over 40 years to a depth of 700 metres. Tim Barnett, of the
Scripps Institute in San Diego, told the American Association for the
Advancement of Science meeting in Washington last month that “the
statistical significance of these results is far too strong to be merely
dismissed and should wipe out much uncertainty about the reality of global
warming”.

The warming of the Arctic could have a big impact on seals, polar bears and
walruses, which depend on winter ice for hunting. In 1997, thousands of
short-tailed shearwaters died because of a bloom of plankton which obscured
the bird’s food supply.

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Caught adrift: A new survey suggests part of the polar bear population is
smaller than previous estimates. The animals are increasingly vulnerable to
global warming but future prospects are unpredictable. (Picture: Oxford
Scientific Films.)

A new study, funded by the Norwegian ministry of the environment, suggests
that polar bear numbers may be lower than previously estimated. Scientists
at St Andrew’s University in Scotland together with scientists from the
Norwegian Polar Institute (NPI) and the University of Oslo carried out a
survey of the Barents Sea region over five weeks using two helicopters and
bears with satellite tags. The team believe that there are 3,000 polar bears
living in the region compared with previous estimates of 5,000.

The region is home to 12 per cent of the world’s polar bears. Though the
large number means safety in the short term, the NPI says that climate
change and organic pollutants may affect the population in the long run.

Norway’s environment minister, Knut Arid Hareide said: “The count gives us a
good basis for the future management of this animal.”

With conflicting evidence about how Arctic regions might fare under global
warming, the fate of polar bears and other inhabitants of the region faces a
particularly difficult future.
Received on Wed Mar 30 12:24:28 2005