Ice cores reveal climate change

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Ice Cores, Etched Perspex inlaid with acrylic (2004)

Perspex discs found at Reverse Garbage hold impressions of change in the Earth’s atmosphere over millions of years.

These first Ice Cores were mere impressions.

The aim now is to animate the information held within Antarctic ice cores, that has been captured by scientific instruments.

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Scanners can see things that our bare eyes can’t.
Working with visual data scanned from actual ice cores, objects and animations can be traces, or memories, of ice core remnant data.

It seems like things are on the move at last, and that there will be enough material to work with to balance the observed and the experienced, the remote past and the transitory moment.

Here’s a paper on the Vostok ice core (2001, revised 2003):

J.-M. Barnola, D. Raynaud, C. Lorius

Laboratoire de Glaciologie et de Géophysique de l’Environnement, CNRS, BP96, 38402 Saint Martin d’Heres Cedex, France

N.I. Barkov

Arctic and Antarctic Research Institute, Beringa Street 38, 199397, St. Petersburg, Russia

Period of Record

417,160 – 2,342 years BP

Methods

In January 1998, the collaborative ice-drilling project between Russia, the United States, and France at the Russian Vostok station in East Antarctica yielded the deepest ice core ever recovered, reaching a depth of 3,623 m (Petit et al. 1997, 1999). Ice cores are unique with their entrapped air inclusions enabling direct records of past changes in atmospheric trace-gas composition. Preliminary data indicate the Vostok ice-core record extends through four climate cycles, with ice slightly older than 400 kyr (Petit et al. 1997, 1999). Because air bubbles do not close at the surface of the ice sheet but only near the firn-ice transition (that is, at ~90 m below the surface at Vostok), the air extracted from the ice is younger than the surrounding ice (Barnola et al. 1991). Using semiempirical models of densification applied to past Vostok climate conditions, Barnola et al. (1991) reported that the age difference between air and ice may be ~6000 years during the coldest periods instead of ~4000 years, as previously assumed. Ice samples were cut with a bandsaw in a cold room (at about -15°C) as close as possible to the center of the core in order to avoid surface contamination (Barnola et al. 1983). Gas extraction and measurements were performed with the “Grenoble analytical setup,” which involved crushing the ice sample (~40 g) under vacuum in a stainless steel container without melting it, expanding the gas released during the crushing in a pre-evacuated sampling loop, and analyzing the CO2 concentrations by gas chromatography (Barnola et al. 1983). The analytical system, except for the stainless steel container in which the ice was crushed, was calibrated for each ice sample measurement with a standard mixture of CO2 in nitrogen and oxygen. For further details on the experimental procedures and the dating of the successive ice layers at Vostok, see Barnola et al. (1987, 1991), Lorius et al. (1985), and Petit et al. (1999).

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From Science at NASA:

Mickey Mouse, Klingon, porpoise, sphere, and leftover turkey are nicknames given to objects found in ancient Antarctic ice from as deep as 1,249 meters beneath Vostok Station.

Richard Hoover (left) of NASA/Marshall and Dr. S.S. Abyzov of the Institute of Microbiology (right) check ESEM images of microbes found in ancient Antarctic ice. The ESEM is visible behind Abyzov (ESEM operator Greg Jerman is partially visible behind Hoover). This image links to a 1,500×1,082-pixel, 576K JPG. Photo credit: NASA/Marshall Space Flight Center.

what was found in the ice?

Dust particles “with unusual spectra” and …

“fluffy white objects, about 1 micron wide and resembling cotton balls.”

“Here’s the shocker,” said Hoover, pointing at the ESEM monitor, “these small coccoid bodies are covered with all this incredible fibrous structure.” The filaments appear to be about 30 to 40 nanometers wide (that’s about 1/10th a wavelength of visible light).

“It’s difficult for me to say what it is,” Abyzov said, “but I tend to agree that this is biological.”

“There are all sorts of microorganisms in the ice. Some are readily recognizable as cyanobacteria, bacteria, fungi, spores, pollen grains, and diatoms, but some are not recognizable as anything we’ve ever seen before,” Hoover said. Many will turn out to be known. It’s just that they look different under the ESEM, which provides details that are not available through other microscopes.

Familiar items include bits of sponge and feather, and diatom fragments

Richard Hoover said: “the most abundant forum of plant life in the Arctic and Antarctic ice are the diatoms.”

I am engraving diatoms in suspended animation.

“What is clearly going on is that when microorganisms freeze, they shut down and go into this anabiotic state,” Hoover explained. Anabiotic means alive but inactive, like suspended animation. Russian scientists have been able to revive and culture bacteria, yeast, fungi, and other microbes found in ice cores.

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An on-line interactive graph of ice core data was designed by Kristin Henry, (Galaxy Goo) and Robert Simmon (NASA GSFC)].

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Posted on Friday, August 17th, 2007