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The potential to access an ice core chronology tuned on local insolation has been demonstrated for the first time in the work of M. Bender (2002) linking the variations of O2/N2 ratios in the air trapped in the Vostok ice with local (78°S) summertime insolation. More recently, it has been shown that the long-term changes in air content, V, recorded in ice from the high Antarctic plateau are also dominantly imprinted by the local summer insolation ( Raynaud et al., 2007). This paper presents a new V record from Vostok, which is compared with the published Vostok O2/N2 record for the same period of time (160–390 ka BP) by using the same spectral analysis methods. The spectral differences between the two properties and the possible mechanisms linking them with insolation through the surface snow structure and the close-off processes are discussed. The main result of our study is that the two experimentally independent local insolation proxies lead to absolute (orbital) timescales, which agree together within less than 1 ka on average. This result strongly adds credibility to the total content and the O2 to N2 ratio of the air trapped in ice as reliable and complementary tools for accurate dating of existing and future deep ice cores.

Icy formations are often found in the cosmos: there are comet's nuclei, polar caps of Mars and of other planets and Europa, the Jupiter's satellite covered with icy crust. Various inclusions of mineral and organic compounds have been permanently accumulated in the ice thickness which protects them from subsequent environmental influence and ensures their reliable and long-term preservation. So icy bodies are unique objects for searching microorganisms and studying ancient ecological events that occurred during formation of icy layers. Complex microbiological and glaciological investigations at Vostok station carried out during a number of years resulted in the discovery of well-preserved cells of microorganisms of different taxonomic groups, as well as plant pollen and unicellular algae in the ice sheet horizons the age of which exceeds 300,000 years. Upon incubation of some samples with radiocarbon labeled organics an evidence of the preservation of some viable microorganisms has been provided. The investigation of ice bodies in an attempt to find any possible form of microscopical life has an advantage over analogous studies of other cosmic solids because the cells of microorganisms and other inclusions can be released from the melted ice without destruction and can be studied unambiguously by different methods of microscopy.

Laser-Raman spectra of Vostok ice recovered from Antarctica have been measured in a frequency range of 10–400 cm−1 in order to observe long-term aging effects on Raman spectra of ice Ih. We found that the intensity of the peak at 300 cm−1 increased as the depth of the ice core increased from 500 to 2452 m. Since no change in the peak height was observed by pressurization, the increase of the peak intensity is attributed to the aging effect on a structural change of ice during a very long period from 28 000 to 209 000 yr. Since this peak is assigned to a translational lattice vibration traveling along the hydrogen bonds, we conclude that the proton arrangement in the Antarctic ice varies with a very long term aging.