Dating Ice

This ice-flow model can be supplemented by certain other methods listed in Table 17.9. The application of methods based on natural or anthropogenic radioactive isotopes is limited because of low concentrations, irregular distribution, and because the basic assumptions of dating are not always satisfied. 

The suceess of the eollaboration of Russian and French scientists who drilled and analyzed the long core at 

The drill site chosen by EPICA is called Concordia Station and is located at 75°06 S and 123°2TE at an elevation of 3,233 m above sea level where the thickness of the East Antarctic ice sheet is 3,200 m. The consortium of scientists and logistics personnel from ten nations first drilled a hole at Kohnen Station in Queen Maud Land for comparison with the climate 

The concentrations of carbon dioxide in the ice of the Dome-C core range from about 300 parts per mil-hon by volume (ppmv) to 172 ppmv (Liithi et al. 2008). These values are lower than the concentration of carbon dioxide in the present atmosphere, which has increased from about 340ppmv in 1980 (Thompson and Schneider 1981) to about 385 ppmv in 2010 (Perkins 2008). Even more noteworthy is the close correlation of warm episodes (i.e., interglacials) and high concentrations of carbon dioxide in air trapped in the ice. Similarly, cold intervals (i.e., glaciations) correlate with low concentrations of carbon dioxide. 

The correlation of temperature fluctuations with variations of the concentrations of carbon dioxide raises the important question  

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In summary, a number of chemical constituents in polar snow and ice have seasonal concentration variations that make them suitable for dating ice cores by counting annual layers. In... 

Figure 9.2. Generalized trend of the concentration of methane in air extracted from dated ice cores. (After Cicerone and Oremland, 1988.)...

Dansgaard W. and Hammer C.U., Geophysical timescales from absolutely-dated ice cores from Greenland. Fys. Tidsskr. (Denmark), 76, 138-140 (1978). 

In the process of electrifying the automobile, the hydrogen FCV has no need for the internal combustion engine (ICE) or the oil it burns. Since their inventions in the late 1800s, spark ignition ICEs used to burn gasoline and compression ignition ICEs used to burn diesel have powered virtually all the billion plus motor vehicles built to date. ICEs are installed in virtually all the 50 million cars, trucks, and buses built annually around the world today. 

This technique of dating ice cores by counting annual layers, identified either visually or isotopically (or both), has been widely used to develop climate histories for the ice sheets in East and West Antarctica. However, the method is limited to about 1,000 years by the progressive thinning of annual layers with depth in the ice sheet. 

Origins of the science associated with thermal insulations coincide with the development of thermodynamics and the physics associated with heat transfer. These technical subjects date to the eighteenth century. Early obseiwations that a particular material was useful as thermal insulation were not likely guided by formal theoi y but rather by trial and error. Sawdust was used, for example, in the nineteenth centui y to insulate ice storage buildings. 

The atmosphere may be an important transport medium for many other trace elements. Lead and other metals associated with industrial activity are found in remote ice caps and sediments. The transport of iron in wind-blown soil may provide this nutrient to remote marine areas. There may be phosphorus in the form of phosphine, PH3, although the detection of volatile phosphorus has not been convincingly or extensively reported to date. 

Hammer, C. U., Clausen, H. B., Dansgaard, W. et al. (1987). Dating of Greenland ice cores by flow models, isotopes, volcanic debris, and continental dust. /. Glacial. 20,3-26. 

Reeh, N. (1989). Dating by ice flow modeling a useful tool or an exercise in applied mathematics In "The Environmental Record in Glaciers and Ice Sheets" (H. Oeschger and C. C. Langway, eds), pp. 141-159. Wiley, New York. 

Salamatin, A. N., Lipenkov, V. Y., Barkov, N. I. et al. (1998). Ice core age dating and paleothermometer calibration based on isotope and temperature profiles from deep boreholes at Vostok Station (East Antarctica). /. Geophys. Res. 103(D8), 8963-8977. 

Adequate pre-shop provision, thorough training, and strict oversight of the shoppers, as described above, were critical to the successful execution of the sample collection phase of the OPMBS. Each shopper received a kit containing sample labels and containers to hold the sampled commodities, ice packs and packaging materials, labels and boxes for use in shipping the collected commodities, written instructions, and forms well before the scheduled date of collection. The sample coordinator monitored sample collection and advised shoppers of actions to take when problems inevitably arose. 

Martinson DG, Pisias NG, Hays JD, Imbrie J, Moore TC, Shackleton NJ (1987) Age dating and the orbital theory of the Ice Ages Development of a high-resolution 0 to 300,000 yr chronostratigraphy. Qrrat Res 27 1-29... 

Interest in long-term latent energy storage in the form of ice and snow dates back to 1975 [10]. The first field experiment was conducted in the winter of 1979-1980, referred to as Project Icebox because of the wooden structure in which the ice was formed, stored, and melted. The water layer was simply exposed to ambient conditions and allowed to freeze. Results indicated that... 

Analyzing the samples back at Caltech, Patterson, Masayo Murozumi, and Chow demonstrated that polar ice is naturally extremely pure but that snow deposited in modern times on Greenland contained roughly 100 times more lead than did preindustrial snow. Most of the lead deposits dated from the twentieth century. Geochemists later used the unique ratio of lead-206 and lead-207 isotopes in the lead to prove that these deposits originated in the United States. 

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