Physical properties of the WAIS Divide ice core
Physical properties of the WAIS Divide ice core
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DOI：
10.3189/2014jog14j100
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发表时间：
2014-01-01
影响因子：
3.4
通讯作者：
Mcconnell, Joseph R.
中科院分区：
文献类型：
--
作者：
Fitzpatrick, Joan J.;Voigt, Donald E.;Mcconnell, Joseph R.
最近完成的WAIS（西南极冰盖）分水岭深冰芯的总深度为3405米，终止于海床上方50米处。可视地层学和颗粒特征的调查表明，在钻井位置的冰柱是不受任何大规模的翻转或不连续性。因此，从这个岩芯得到的气候记录很可能是连续和可靠的。测量的晶粒生长速率，再结晶特性，并在气候转变的粒度响应符合目前的理解。杂质含量与晶粒尺寸的相关性分析表明，杂质对晶粒尺寸有明显的控制作用。气泡数密度、气泡大小和形状通过气泡冰的整个范围呈现。在观察到气泡伸长的情况下，伸长的方向优选平行于基面（0001）的轨迹。晶粒的优选结晶取向存在于测量的最浅的样品中，并且随着深度增加，进展到垂直环带图案，该图案收紧到垂直单峰织物。在最深、最热的冰中，随着颗粒尺寸的迅速增加，这种单一的最大值结构转变为多个最大值。在最深的样品中，杂质介导的粒度上的织物的强烈依赖性是明显的。
The WAIS (West Antarctic Ice Sheet) Divide deep ice core was recently completed to a total depth of 3405 m, ending similar to 50 m above the bed. Investigation of the visual stratigraphy and grain characteristics indicates that the ice column at the drilling location is undisturbed by any large-scale overturning or discontinuity. The climate record developed from this core is therefore likely to be continuous and robust. Measured grain-growth rates, recrystallization characteristics, and grain-size response at climate transitions fit within current understanding. Significant impurity control on grain size is indicated from correlation analysis between impurity loading and grain size. Bubble-number densities and bubble sizes and shapes are presented through the full extent of the bubbly ice. Where bubble elongation is observed, the direction of elongation is preferentially parallel to the trace of the basal (0001) plane. Preferred crystallographic orientation of grains is present in the shallowest samples measured, and increases with depth, progressing to a vertical-girdle pattern that tightens to a vertical single-maximum fabric. This single-maximum fabric switches into multiple maxima as the grain size increases rapidly in the deepest, warmest ice. A strong dependence of the fabric on the impurity-mediated grain size is apparent in the deepest samples.