Ice, glacial

Fig. 11-5 CO2 content of air bubbles trapped in glacial ice from Greenland and Antarctica, showing a pre-industrial concentration of ca. 280 ppmv.

Measurements of CO2 concentrations in air bubbles trapped in glacial ice (Berner et ah, 1980 Delmas et ah, 1980 Jouzel et ah, 1993 Raynaud et ah, 1993) show that atmospheric Pqo was about 200 ppmv toward the end of the last glaciation 20000 years ago (Fig. 11-19). 

Two different investigations have been directed to a glacial ice core (GISP2) from Greenland ... 

Tung HC, NE Bramall, PB Price (2005) Microbial origin of excess methane in glacial ice and implications for life on Mars. Proc Natl Acad Sci USA 102 18292-18296. 

Schuster PF, Krabbenhoft DP, Naftz DL, Cecil FD, Olson ML, Dewild IF, Susong DD, Green JR, Abbott ML. 2002. Atmospheric mercury deposition during the last 270 years a glacial ice core record of natural and anthropogenic sources. Env Sci Technol 36 2303-2310. 

Patterson s friend Edward D. Goldberg at the Scripps Institution of Oceanography in La Jolla, California, had tipped him off that one of the best records of the world s climate is embedded in thin layers of glacial ice at high altitudes or near the poles. Snow, dust, and fog deposit chemicals from the atmosphere onto the ice, where they remain undisturbed for thousands of years. As Patterson quickly realized, Only the quiescent ice sheets in the arid, perpetually frozen polar regions of the Earth provide annual layers of precipitation that are undisturbed by percolation and mechanical mixing, that are relatively free of dusts and salts, and also are thin enough to be accessible even when centuries old. ... 

Over the polar regions of the north, snow, fog and dust precipitated out the lead. Unknown to mankind, the lead lay there, encased in Greenland s glacial ice cap, for 2500 years. 

Using the rock cycle as an example, we can compute the turnover time of marine sediments with respect to river input of solid particles from (1) the mass of solids in the marine sediment reservoir (1.0 x 10 g) and (2) the annual rate of river input of particles (1.4 X lO g/y). This yields a turnover time of (1.0 x 10 " g)/(14 x lO g/y) = 71 X lo y. On a global basis, riverine input is the major source of solids buried in marine sediments lesser inputs are contributed by atmospheric feUout, glacial ice debris, hydrothermal processes, and in situ production, primarily by marine plankton. As shown in Figure 1.2, sediments are removed from the ocean by deep burial into the seafloor. The resulting sedimentary rock is either uplifted onto land or subducted into the mantle so the ocean basins never fill up with sediment. As discussed in Chapter 21, if all of the fractional residence times of a substance are known, the sum of their reciprocals provides an estimate of the residence time (Equation 21.17). 

According to the passage, why does glacial ice often appear blue ... 

Measurements of POCs in the snow and glacial ice of mountains have revealed that anthropogenic contaminants are not only present in these media, but that some occur at higher concentrations at higher elevations than at lower elevations [3,40], Specifically, the HCHs, lower chlorinated PCBs and endosulfan showed this trend in the mountains of Western Canada [3], while p, p -DDT and p, p -DDD did so in snow collected from four elevations on Mt. Everest [40],... 

Kezar Lake is a typical glacial ice-scour lake in North Sutton,... 

At first they feared the worst. A body embedded in glacial ice - what else could this be but the gruesome record of a climbing accident Or perhaps even, to judge from the apparent wound on the back of the dead man s head, something more sinister. Either way, Helmut and Erika Simon, hiking in the Alps along the border of Austria and Italy on 19 September 1991, were deeply disturbed by their discovery. 

Table 3.15 Arsenic in glacial ice, glacial sediments, and loess...

Weiss, H.V. and Bertine, K.K. (1973) Simultaneous determination of manganese, copper, arsenic, cadmium, antimony and mercury in glacial ice by radioactivation. Analytica Chimica Acta, 65(2), 253-59. 

Global releases of radium-226 by the combustion of coal have been estimated as 150 Ci (5,550,000,000 kBq) per year (Jaworowski et al. 1971). It has also been observed that radium-226 concentrations in glacial ice samples collected in Europe have increased by a factor of 100 during the last 80 years. The source of these elevated levels of radium may have been emissions from fossil fuels (Jaworowski et al. 1971). 

Figure 10.36. The CO2 content of air bubbles trapped in Antarctic glacial ice at the Vostok station as a function of depth in the ice core. Two ages of the ice are shown. (After Barnola et al., 1987.)...

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