Ice core drilling

Several laboratories therefore intend to measure profiles of these isotopes on ice cores drilled in polar ice caps. The new technique also makes possible measurements of the 14C in the C02 occluded in about 30 kg of ice. From the 14C measurements again twofold information is expected ... 

IMPLICATIONS FOR AND FINDINGS FROM DEEP ICE CORE DRILLINGS — AN EXAMPLE THE ULTIMATE TENSILE STRENGTH OF ICE AT HIGH STRAIN RATES... 

Fig. 17.31 The history of temperature fluctuations based on the isotope composition of oxygen and hydrogen in the ice core drilled by the European Project for Ice Coring in Antarctica (EPICA) at Concordia Station on Dome C (75°06 S, 123°21 SE) is closely correlated with the concentrations of carbon dioxide in the ice, both of which can be indexed to the marine isotope stages in Fig. 17.30. The correlation of these parameters confirms the scope of the chmate fluctuations which include nine cold spells that terminated abruptly during the Pleistocene Epoch (i.e., Tj-Tjj, etc.). The temperature profile (black curve) is based on measurements of 6D and was plotted on the EDC3...

Layers of ice containing disseminated particles of volcanic origin (i.e., tephra) are a common feature of blue ice areas and in the vicinity of volcanic vents in the Transantarctic Mountains. Volcanic tephra have also been found in the ice cores drilled at South Pole Station, Dome C, Vostock Station, and at Byrd Station, as well as in the glacial deposits that cover the floor of Wright Valley (Jones et al. 1973b Boger and Faure 1988). 

The ice core drilled in 1983/84 at South Pole Station contained a 3-mm tephra layer at a depth of 303.44 m (Palais et al. 1987). The tephra are composed of vesic-nlar glass with crystals of quartz, pyroxene, and pla-gioclase. The bulk chemical composition of these tephra plots close to the boundary between the andesite and benmoreite fields in Fig. 17.44 in strong contrast to the tephra in the cores at Byrd Station and Dome C (See also Koeberl 1990, Table 1). 

Figure 10.60 Bubbles of methane gas frozen in the polar ice. This is a polarized light micrograph of an ice sample extracted in Antarctica. The sample was from an ice core drilled to a depth of 234m... 

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