A glacio-chemicalcharacterization of the new EPICA deep-drilling site on Amundsenisen, Dronning Maud Land, Antarctica
A glacio-chemicalcharacterization of the new EPICA deep-drilling site on Amundsenisen, Dronning Maud Land, Antarctica
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DOI：
10.3189/172756402781816474
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发表时间：
2002-01-01
期刊：
影响因子：
--
通讯作者：
Miller, H
中科院分区：
文献类型：
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作者：
Göktas, F;Fischer, H;Miller, H
在欧洲南极冰芯计划(EPICA)的框架内，在南极Dronning Maud陆地(DML)进行了一项冰化学前期调查，以调查季节和空间变化。除硝酸盐外，所有离子物种都表现出明显的季节性周期，硝酸盐受到沉积后变化的影响。海盐浓度在冬末春末达到最大值，而硫酸盐以海洋生物来源为主，在秋季和春夏末都出现了浓度较高的双峰。甲烷磺酸盐(MSA)也显示出强烈的秋季高峰，但只有轻微的迹象表明第二个高峰出现在春末/夏季，就像硫酸盐一样。由于沉积后的变化，MSA的季节旋回在降雪中进一步消失。这些变化也反映在MSA的空间分布上。表层MSA浓度随海拔高度和积累率的增加而降低，但随着冰芯积累率的增加，老化雪的积累量明显增加。非海盐硫酸盐的降雪量减少了40%，新雪和老雪的积雪增加了约80%。虽然平均硝酸盐浓度的地理差异可以忽略不计，但海盐随着海拔的升高呈指数下降。这项研究的结果证实，在DML(75°00.10‘S，0°04.07’E)新的EPICA深部钻探现场的数据将具有该地区的代表性，高分辨率分析方法将使深冰芯的准确地层测年成为可能。
In the framework of the European Project for Ice Coring in Antarctica (EPICA) a glacio-chemical pre-site survey was carried out in Dronning Maud Land (DML), Antarctica, to investigate seasonal and spatial variations. All ion species show pronounced seasonal cycles with the exception of nitrate, which is subject to post-depositional alterations. Sea salt reaches maximum concentrations in late winter/spring, while sulphate, being mainly of marine biogenic origin, shows a double peak with high concentrations both in autumn and in late spring/summer. Methanesulphonate (MSA) also shows a strong autumn peak but only slight indications of a second peak in late spring/summer, as seen for sulphate. Due to post-depositional changes, the seasonal cycle of MSA vanishes further down in the firn. These changes are also reflected in the spatial distribution of MSA. While surface MSA concentrations decline with altitude and higher accumulation rates, concentrations of aged snow show a strong increase with higher accumulation rates in our ice cores. Non-sea-salt sulphate shows a 40% decrease with an increase in snow accumulation of about 80% in recent and aged snow. While the geographical variation is negligible for average nitrate concentrations, sea salt shows an exponential decline with altitude. The outcome of this study confirms that the data of the new EPICA deep drilling site in DML (75degrees00.10' S, 0degrees04.07' E) will be representative for this region, and high-resolution analytical methods will allow accurate stratigraphic dating of a deep ice core.