The SP19 chronology for the South Pole Ice Core – Part 1: volcanic matching and annual layer counting
The SP19 chronology for the South Pole Ice Core – Part 1: volcanic matching and annual layer counting
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DOI：
10.5194/cp-15-1793-2019
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发表时间：
2019-10
影响因子：
4.3
通讯作者：
D. Winski;T. Fudge;D. Ferris;E. Osterberg;J. Fegyveresi;J. Cole‐Dai;Zayta Thundercloud;Thomas S. Cox;K. Kreutz;Nikolas Ortman;C. Buizert;Jenna A. Epifanio;E. Brook;R. Beaudette;J. Severinghaus;T. Sowers;E. Steig;Emma C. Kahle;T. Jones;Valerie Morris;M. Aydin;M. R. Nicewonger;K. Casey;R. Alley;E. Waddington;N. Iverson;N. Dunbar;R. Bay;Joseph M. Souney;M. Sigl;J. McConnell
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文献类型：
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作者：
D. Winski;T. Fudge;D. Ferris;E. Osterberg;J. Fegyveresi;J. Cole‐Dai;Zayta Thundercloud;Thomas S. Cox;K. Kreutz;Nikolas Ortman;C. Buizert;Jenna A. Epifanio;E. Brook;R. Beaudette;J. Severinghaus;T. Sowers;E. Steig;Emma C. Kahle;T. Jones;Valerie Morris;M. Aydin;M. R. Nicewonger;K. Casey;R. Alley;E. Waddington;N. Iverson;N. Dunbar;R. Bay;Joseph M. Souney;M. Sigl;J. McConnell
抽象的。南极冰芯(SPICEcore)是在2014-2016年钻探的，目的是提供全新世和晚更新世期间南极东部古气候条件的详细多代理档案。对这些记录的解释需要准确的深度-年龄关系。这里，我们给出了SPICEcore(SP19)冰层年龄的时间刻度。通过251次火山事件的地层匹配，SP19与西南极冰盖分水岭(WAIS Divide)冰芯的WD2014年代学同步。这些事件表明SPICEcore底部的年龄为54 302±519 BP(1950年前)。在钠和镁离子中识别的年层被用来在地层火山连接点之间进行内插，得到了整个全新世的年度分辨年代学。全新世期间的估计时间尺度不确定性相对于2014年WD2014年不到18年，但1800到3100 BP之间的时间间隔除外，因为火山联络点的广泛分布，估计不确定性达到±25年。在全新世之前，相对于2014年WD2014，不确定因素仍然存在124年内。结果表明，全新世的平均堆积速率为7.4cmyr−1(水当量)。积累率的时间变异性与现代积累率空间格局对稳态冰流的预期是一致的。氮气中硝酸盐浓度、硝酸盐季节变幅和δ15N的时间变化与预期的累积速率变化一致。该地点高度多变但约束良好的全新世聚集史有助于提高对沉积敏感气候指标的科学理解，如氮的δ15N和光解化合物。
Abstract. The South Pole Ice Core (SPICEcore) was drilled in 2014–2016 to provide a detailed multi-proxy archive of paleoclimate conditions in East Antarctica during the Holocene and late Pleistocene. Interpretation of these records requires an accurate depth–age relationship. Here, we present the SPICEcore (SP19) timescale for the age of the ice of SPICEcore. SP19 is synchronized to the WD2014 chronology from the West Antarctic Ice Sheet Divide (WAIS Divide) ice core using stratigraphic matching of 251 volcanic events. These events indicate an age of 54 302±519 BP (years before 1950) at the bottom of SPICEcore. Annual layers identified in sodium and magnesium ions to 11 341 BP were used to interpolate between stratigraphic volcanic tie points, yielding an annually resolved chronology through the Holocene. Estimated timescale uncertainty during the Holocene is less than 18 years relative to WD2014, with the exception of the interval between 1800 to 3100 BP when uncertainty estimates reach ±25 years due to widely spaced volcanic tie points. Prior to the Holocene, uncertainties remain within 124 years relative to WD2014. Results show an average Holocene accumulation rate of 7.4 cm yr−1 (water equivalent). The time variability of accumulation rate is consistent with expectations for steady-state ice flow through the modern spatial pattern of accumulation rate. Time variations in nitrate concentration, nitrate seasonal amplitude and δ15N of N2 in turn are as expected for the accumulation rate variations. The highly variable yet well-constrained Holocene accumulation history at the site can help improve scientific understanding of deposition-sensitive climate proxies such as δ15N of N2 and photolyzed chemical compounds.