EPICA Dome C Ice Core Timescales EDC3

The EPICA (European Project for Ice Coring in Antarctica) Dome C drilling in East Antarctica has now been completed to a depth of 3260 m, at only a few meters above bedrock. Here we present the new EDC3 chronology, which is based on the use of 1) a snow accumulation and mechanical flow model, and 2) a set of independent age markers along the core. These are obtained by pattern matching of recorded parameters to either absolutely dated paleoclimatic records, or to insolation variations. We show that this new time scale is in excellent agreement with the Dome Fuji and Vostok ice core time scales back to 100 kyr within 1 kyr. Discrepancies larger than 3 kyr arise during MIS 5.4, 5.5 and 6, which points to anomalies in either snow accumulation or mechanical flow during these time periods. We estimate that EDC3 gives accurate event durations within 20% (2 sigma) back to MIS11 and accurate absolute ages with a maximum uncertainty of 6 kyr back to 800 kyr.

欧洲南极冰芯钻探计划（European Project for Ice Coring in Antarctica, EPICA）在东南极的穹顶C（Dome C）钻探项目现已完成，钻进深度达3260米，仅距基岩数米。本文提出全新的EDC3年代标尺，其构建基于两项依据：其一为积雪积累与冰体力学流动模型，其二为冰芯沿线的一系列独立年代标记物。上述标记物通过将实测参数与绝对定年的古气候记录，抑或是太阳辐射变化序列进行模式匹配而获得。研究表明，这一新年代标尺与富士穹顶（Dome Fuji）和沃斯托克（Vostok）冰芯的年代标尺在回溯至100 kyr的范围内，偏差仅在1 kyr以内。在海洋同位素阶段（Marine Isotope Stage, MIS）5.4、5.5及6时期，二者的偏差超过3 kyr，这表明该时段内积雪积累或冰体力学流动存在异常。我们估算得出，EDC3年代标尺在回溯至MIS11时，事件持续时间的估算误差处于20%以内（2σ，2倍标准差）；而回溯至800 kyr时，绝对定年的最大不确定度为6 kyr。

搜集汇总

背景与挑战

背景概述

EPICA Dome C Ice Core Timescales EDC3数据集提供了南极洲EPICA Dome C冰芯的深度与年龄关系的时间尺度数据，基于雪积累/冰流模型和独立年龄标记校准，适用于古气候研究。数据集包含冰基质和气泡的年龄信息，覆盖深度范围0-3189.45米，时间跨度为1993-2004年。