New MIS 19 EPICA Dome C high resolution deuterium data: Hints for a problematic preservation of climate variability at sub-millennial scale in the "oldest ice"

作者：Pol K^*; Masson Delmotte V; Johnsen S; Bigler M; Cattani O; Durand G; Falourd S; Jouzel J; Minster B; Parrenin F; Ritz C; Steen Larsen H C; Stenni B

来源：Earth and Planetary Science Letters, 2010, 298(1-2): 95-103.

DOI：10.1016/j.epsl.2010.07.030

• water stable isotopes
• ice cores
• Antarctica
• isotopic diffusion

Marine Isotope Stage 19 (MIS 19) is the oldest interglacial period archived in the EPICA Dome C ice core (similar to 780 ky BP) and the closest "orbital analogue" to the Holocene - albeit with a different obliquity amplitude and phase with precession. New detailed deuterium measurements have been conducted with a depth resolution of 11 cm (corresponding time resolution of similar to 130 years). They confirm our earlier low resolution profile (55 cm), showing a relatively smooth shape over the MIS 20 to MIS 18 time period with a lack of sub-millennial climate variability, first thought to be due to this low resolution. The MIS 19 high resolution profile actually reveals a strong isotopic diffusion process leading to a diffusion length of at least similar to 40 cm erasing sub-millennial climate variability. We suggest that this diffusion is caused by water-veins associated with large ice crystals at temperatures above -10 degrees C, temperature conditions in which the MIS 19 ice has spent more than 200 Icy. This result has implications for the selection of the future "oldest ice" drilling site.

• 出版日期2010-9-15
• 单位中国地震局