A chronology for the Dome C deep ice-core site through radio-echo layer correlation with the Vostok ice core, Antarctica

摘要

Ice at the new Dome C drill site is correlated directly with the Vostok ice-core record using internal radio-echo layering in the Antarctic Ice Sheet. Layering observed on 60 MHz radar records at ice depths greater than 1000 m is a result of electro-magnetic wave reflections from acidic ice layers formed, it is assumed, by volcanic eruption-derived aerosols. These acidic layers represent isochronous surfaces within the ice sheet. We are able to trace five prominent layers for over 500 km across the Antarctic Ice Sheet, between Vostok and the new ice-core site at Dome C. This correlates the stratigraphy and depth-age relationship between the two sites. The thickness of ice deposited over the last glacial cycle (120,000 years) at Dome C is 300 m greater than at Vostok and, at comparable depths, the ice at Dome C is between about 10,000 and 25,000 years younger than at Vostok. [References: 16]