Climate change stories from the abyss

Aug 29, 2012
Earth

An international team of scientists have shed new light on the world's history of climate change.

The Pacific Ocean has remained the largest of all oceans on the planet for many million years. It covers one third of the Earth's surface and has a mean depth of 4.2 km. Its biologically productive equatorial regions play an important role particularly to the and long-term development.

During a four-month expedition of the Integrated Programme (IODP) on board the US JOIDES Resolution an international team of more than 100 scientists and technicians recovered 6.3 kilometers of sediment cores from water depths between 4.3 and 5.1 km and drilled 6.3 km of sediment cores at eight locations.

The cores offered an excellent archive of Earth's history and showed how development during the past 55 million years is mirrored and influenced by geochemical processes deep within the ocean.

The findings are published in the latest edition of Nature.

Professor Heiko Pälike, of the University of Southampton and National Oceanography Centre, Southampton was co-chief scientist of the cruise and lead author of the Nature study.

He explains: "Nowadays we often discuss global warming induced by man-made carbon dioxide. However, on geological timescales of millions of years other processes determine the carbon cycle."

Volcanoes are one major source of carbon dioxide input to the atmosphere. On the other hand the is removed by weathering of rocks made up of carbonate.

"The overall balance of these processes is reflected in the 's carbonate compensation depth, the CCD," the MARUM scientist continues.

"This invisible surface is defined as the depth in the oceans at which the is dissolved. Hardly any biological remains made from carbonate below the CCD, for example chalk and , are preserved. Instead the sediment that consists mostly of clay and plankton remains made from silica.

"The interesting point in our study is that the carbonate boundary is fluctuating over time. It shallows during periods of warm climate and normally deepens when ice age conditions prevail."

In the study, Professor Pälike and co-workers demonstrate that in the equatorial Pacific the CCD was at 3.3 to 3.6km 55 million years ago. Between 52 and 47 million years ago, when very warm climate conditions prevailed, the CCD leveled up to 3 km. 34 million years ago, when the Earth slowly but steadily cooled and the first ice domes formed in Antarctica the CCD went down too. 10.5 million years ago it reached 4.8 km.

The cores drilled during the expedition strikingly demonstrate that the interplay of climate development and carbon cycle was not a one-way street at all.

"From 46 to 34 million years ago, when Earth turned into a permanent icehouse, our record reveals five intervals during which the CCD fluctuated upwards and downwards in the range of 200 and 900 metres," Professor Pälike says. "These events, that often mirror warming and cooling phases, persisted between 250,000 and one million years."

Similar episodes were registered in the for later parts of the Earth's history. 18.5 million years ago the CCD moved upward about 600 metres – only to sink down to 4.7 km 2.5 million years later. Today, the Pacific carbonate compensation depth is at 4.5 km.

Explore further: Lava from Hawaii volcano picks up speed

More information: To access more data and information from the Pacific Equatorial Age Transect (PEAT) expeditions, please see: publications.iodp.org/proceedi… 320_321/32021toc.htm

The paper, titled "A Cenozoic record of the equatorial Pacific carbonate compensation depth," appears in the August 30, 2012 issue of the journal Nature. (doi:10.1038/nature11360)

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cantdrive85
1.7 / 5 (11) Aug 29, 2012
Another deduction that one could arrive at is that the change in climate is what alters the carbonate levels, but taxing the pleebs on a naturally occurring process would be slightly more difficult for them to force upon us.
rubberman
1 / 5 (2) Aug 29, 2012
Another deduction that one could arrive at is that the change in climate is what alters the carbonate levels, but taxing the pleebs on a naturally occurring process would be slightly more difficult for them to force upon us.


From the article - "The interesting point in our study is that the carbonate boundary is fluctuating over time. It shallows during periods of warm climate and normally deepens when ice age conditions prevail."

Granted the article mentioned nothing of Pleebs...
NotParker
1.4 / 5 (11) Aug 29, 2012
"Volcanoes are one major source of carbon dioxide input to the atmosphere."

Not according to the cult.
RealityCheck
2.8 / 5 (11) Aug 29, 2012
@cantdrive85:
..the change in climate is what alters the carbonate levels, but taxing the pleebs on a naturally occurring process would be slightly more difficult for them to force upon us.


@NotParker:
"Volcanoes are one major source of carbon dioxide input to the atmosphere."

Not according to the cult.

Parsing 'conveniently' there guys? Note where it says:

"Nowadays we often discuss global warming induced by man-made carbon dioxide. However, on geological timescales of millions of years other processes determine the carbon cycle." Volcanoes are one major source of carbon dioxide input to the atmosphere. On the other hand the greenhouse gas is removed by weathering of rocks made up of carbonate."

See? Normal cycles are geologic, not short like recent human impacts timespan.

And volcanic contributions are already part of the natural net-net zero recycling.

ADDITIONAL human contribution now exacerbate/skew timescale/net-net of natural cycles/extremes.

Cheers
NotParker
1.6 / 5 (7) Aug 29, 2012
"In point of fact, the total worldwide estimate of roughly 55 MtCpa is by one researcher, rather than "scientists" in general.

More importantly, this estimate by Gerlach (1991) is based on emission measurements taken from only seven subaerial volcanoes and three hydrothermal vent sites.

Yet the USGS glibly claims that Gerlach's estimate includes both subaerial and submarine volcanoes in roughly equal amounts.

Given the more than 3 million volcanoes worldwide indicated by the work of Hillier & Watts (2007), one might be prone to wonder about the statistical significance of Gerlach's seven subaerial volcanoes and three hydrothermal vent sites. "

http://carbon-bud...011.net/
Vendicar_Decarian
3 / 5 (2) Aug 30, 2012
The earth's surface area is 200 million square miles.

"Given the more than 3 million volcanoes worldwide indicated by the work of Hillier & Watts (2007)" - ParkerTard

If ParkerTard's lunacy were correct then there would be one volcano on average for every 66 square miles over the earth's surface.

One "volcano" for every square on the earths surface that is 8 miles to a side.

ParkerTard is mentally diseased.
Vendicar_Decarian
1 / 5 (1) Aug 30, 2012
ParkerTard's source for information is Timothy Casey, who is some flunky with a BSc in Geology.

Having a BSc, means he knows a little more than someone who graduated from high school.

Woo Hoo...
Vendicar_Decarian
3 / 5 (2) Aug 30, 2012
ParkerTard can't seem to distinguish the difference between geologic time and Daylight Savings Time.

It is similar to his inability to distinguish between climate and weather.

"Not according to the cult." = ParkerTard

It is all part of his mental disease.
Vendicar_Decarian
not rated yet Aug 30, 2012
Poor mentally diseased ParkerTard
Poor little Tard