Byrd Station,

A test of the 39Ar method is the measurements on Ar extracted from air occluded in polar ice. On the occasion of several polar projects at Byrd Station, Antarctica, under the auspices of... 

Figure 11. Camp Century, Greenland and Byrd Station, Antarctica ice cores COs contents of the first gas extraction fraction and S1S0 profiles (50). The S,sO profiles are from Dansgaard and coworkers, and the ages are calculated according to Ref. 54.

Figure 1 is a map of Antarctica showing the locations of Byrd Station, Allan Hills, and other well-marked sites. 

Stable Isotope Analyses of Byrd Station Cores and Inter-hemispheric Climatic Implications, Science, 1970. 168,... 

Figure 14.13 shows C02 concentrations measured in ice cores at the Byrd Station in Antartica from 5000 years before the present (bp) to 40,000 years bp (Anklin et al., 1997). The use of ice core data for elucidating atmospheric composition is discussed by Delmas (1992) and in more detail in Section E.l. As seen in Fig. 14.13, atmospheric C02 concentrations about 5000 years ago were only 280 ppm. (Note that interpretation of such ice core data must be carried out with care since there is evidence that in some cases, C02 can be produced in the ice from decomposition of carbonate e.g., see Smith et al., 1997.)... 

FIGURE 14.13 Concentrations of atmospheric C02 measured using gases trapped in ice cores from Byrd Station, Antarctica, from 5000 to 40,000 years before the present (bp) (adapted from Anklin et al., 1997). 

Ice cores have been drilled at several places in the Antarctic, including the research outposts at Vostok and Byrd Station. What they tell us is largely consistent with the climate records obtained from the Greenland ice sheets on the other side of the world, as well as with those from marine sediment cores. One can double-check these ice-core records because the ratio of H to deuterium in the water molecules of the ice also acts as an atmospheric thermometer (Fig. 156). 

Epstein S. and Sharp R. P. (1970) Antarctic ice sheet stable isotope analyses of Byrd station cores and interhemispheric climatic implications. Science 16, 1570-1572. 

Fig. 2.18 The tractor train of the Meirie-Bytd-Land oversnow traverse left Byrd station in West Antarctica on November 1, 1958, as part of the exploration of Antarctica during the IGY. The...

The tractor train that left Byrd Station in Fig. 2.18 consisted of three Sno-cats each of which pulled a sled. The leading tractor, known as the Sally Jeanne, was driven by Bill Long assisted by Fred Darling. This tractor carried a crevasse detector that is visible in Fig. 2.18. Occasional mechanical breakdowns of the vehicles, bad weather, and difficulties with crevasses limited the daily progress of the tractors to less than 36 km. The tractor train was resupplied from Byrd Station by a Dakota R4D aircraft that brought fuel for the tractors, food and mail for the crew, and, at least once, a dentist who treated one... 

Eventually the tractor train arrived at Station 414 at the foot of the Horlick Mountains and was delayed there by lack of fuel. The resupply plane from Byrd Station had to turn back several times because of bad weather, problems with radio transmissions, and mechanical problems. While the group waited for several days for the plane. Bill Long and three of his companions decided to climb Ml Glossopteris which is one of the highest mountains in that part of Antarctica at 2,867 m above sea level. 

Fig. 2.19 This picture taken by Emil Schulthess, a Swiss photographer who spent some time in the field with the Byrd-Station traverse group, captures the moment Bill Long returned to the Sno-cats at Station 414 after he and his companions had successfully climbed Mt. Glossopteris in the...

Long WE (1959) Preliminary report of the geology of the central range of the Horlick Mountains, Antarctica. Ohio State Univ Res Found Rept 825-2, Part 7 1-23 Long WE (1961) Byrd Station and Marie Byrd Land traverse, 1958/59. Ohio State Univ Res Found Rept 825-2, Part 11 1-296... 

Palais JM (1985) Tephra layers and ice chemistry in the Byrd-Station ice core, Antarctica. Ph.D. dissertation. Dept. Geol. Minertil., The Ohio State University, Columbus, OH... 

The ice sheet was penetrated by drilling at Vostok Station (Russia) on the East Antarctic ice sheet and at Byrd Station (USA) in West Antarctica. The resulting cores contain valuable records of past climatic conditions, but only the core at Byrd Station recovered samples of the subglacial bedrock. The climate record contained in these cores and in the core that was recently recovered at Dome C will be featured in a later section of this chapter. 

The chemical composition of ice in the long cores that were recovered in East Antarctica at Dome C (74°39 S, 2A° 0 E), Vostok (78- 30 S, 106 54 E) and South Pole (90 S) were determined by Petit et al. (1981), deAngehs et al. (1984), and Delmas et al. (1982a), respectively. The ice in the core drilled at Byrd Station in West Antarctica was analyzed by Palais (1985) and Palais and Legrand (1985). 

The Byrd-Station ice core was drilled through the West Antarctic ice sheet in 1968 and reached bedrock at a depth of 2,164 m (Gow et al. 1968). This core contains about 2,000 layers of volcanic ash or tephra (Gow and Williamson 1971 Gow 1971). The term includes all volcanic ejecta regardless of the diameters of the particles. These tephra were subsequently described by Kyle and Jezek (1978), Gow et al. (1979), and Kyle et al. (1981). In addition, Epstein et al. (1970) and Johnsen et al. (1972) demonstrated by means of the values of the ice that the Byrd-Station core contains a record of the transition from the cold climate of the Wisconsinan ice age to the present Holocene interglacial. 

The Byrd-Station ice core confirmed and extended conclusions reached previously from the study of the Camp-Century core drilled in northwestern Greenland in 1966 (Dansgaard et al. 1969, 1971 Johnsen et al. 1972 Morner 1972, 1974 Langway et al. 1985). The ice of the Camp-Century core also contains tephra that originated from volcanic eruptions in Iceland (Hammer and Clausen 1981 Hammer 1984). 

The concentrations of cations Na+, Mg +, K+, NH, and H+and anions CL, NO, and SOl in ice of the Byrd-Station core were determined by Palais (1985) and by Palais and Legrand (1985) who divided the core into four segments based on climate criteria derived from the profile. The average concentrations of the ions in each of the segments are summarized in Table 17.12. 

Table 17.12 Average concentrations of cations and Legrand 1985) anions in four climatic intervals of the Byrd Station core (Palais and ...

Palais and Legrand (1985) concluded that the ice of the Byrd Station core contains sodium chloride (NaCl) and sodium sulfate (Na SO ) of marine origin. The interactions of ions during transport from the surface of the ocean to the interior of Antarctica permits elemental fractionation which causes an excess of Cl" in some places and an excess of Na+in others. The data in Table 17.12 indicate that the Byrd-Station ice core contains an excess of Cl" over Na+(not shown) but an excess of Na+as Na SO occurs in the ice of the Vostok core (deAngelis et al. 1984). 

The study of microparticles in Antarctic ice cores by L.G. Thompson and E. Mosley-Thompson at The Ohio State University (Thompson et al. 1975, 1981 Thompson 1977a, b Mosley-Thompson 1979 Thonpson and Mosley-Thompson 1981) indicated that the concentration of dust particles in ice cores from the South Pole and Dome C in East Antarctica, from Byrd Station in West Antarctica, as well as from Camp Century in northwestern Greenland have certain common characteristics identified in Table 17.13. The conclusions that are derivable from the data include ... 

Average Concentration Antarctica Dome C Byrd station Greenland Camp century... 

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). 

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