Dome Fuji, Antarctica Core DF2 1-cm Electrical Conductivity Measurements

Dome Fuji, Antarctica Ice Core DF2 1-cm Electrical Conductivity Measurements (ECM) at -20C for depth range 875 - 2200m.The climatic record from the 2nd Dome Fuji (Antarctica) ice core (DF2 core as 3035m deep ice core) was analyzed using ECM (electrical conductivity measurements). The DF2 core, reaching nearly to the ice sheet bed, was drilled in the period 2004-2007 at a site ~43 m away from the DF1 borehole. Mothod of the ECM measurement is as follows. After equilibrating for 1 day at the cold-room temperature at Dome F, all core sections, which were 93mm in diameter and about 1.5m long, were cut parallel to their central axes. The cut surfaces were further finished with a microtome knife to make fresh, smooth surfaces. Immediately after a surface was cut and finished, two ECM electrodes were dragged along the surface with a 400V d.c. potential difference. Although the signal was sampled every 2mm, we provide only 10mm running averages of the data to remove noise. The ECM electrodes were automatically dragged along the ice with a moter module. The electrodes were aligned perpendicular to the core axis and 15mm apart. The effective resolution of the electrodes approximately equaled the distance between the electrodes (15mm); based on a physical principle that the electrical field decreases inversely proportional to the distance from a given location to each electrode. Within this distance, about 65% of the lines of electrical force cross. Measurement temperature is -20C.In 2015, Fujita, Parrenin et al. (2015) volcanically synchronized two deep ice cores, Dome Fuji (DF) and EPICA Dome C (EDC), drilled at remote dome summits in Antarctica, to improve our understanding of their chronologies. For their study, the ECM data of the DF2 core were used from a limited depth range 875 - 2200m. Here, we open these data to the public. The data have two information of the depth. The first column is the depth of the DF2 core. The third column is the DF2 depths converted into equivalent depths of the DF1 core. The second column is the electrical current between the electrodes. Note that, in this version of the data, no actions for noise cleaning were done. Except the averaging for every 10mm, data is still a kind of raw data.南极富士穹顶（Dome Fuji）DF2冰芯在-20℃、深度范围875~2200米区间内的1厘米级电导率测量（Electrical Conductivity Measurements, ECM）数据集。 本数据集针对第二座南极富士穹顶冰芯（DF2冰芯为总深度3035米的深冰芯）的气候记录，采用ECM技术开展了分析。该DF2冰芯于2004—2007年在距DF1钻孔约43米处钻取，几乎抵达冰盖基床。 ECM测量流程如下：将直径93毫米、长约1.5米的冰芯段置于富士穹顶冷室中平衡1天后，沿其中心轴平行切割。随后用切片刀对切割面进行精加工，得到平整新鲜的表面。在切割与精加工完成后，立即以400伏直流电势差将两个ECM电极沿表面拖动采集信号。尽管采样间隔为2毫米，但为去除噪声，本数据集仅提供10毫米滑动平均后的数据。ECM电极通过电机模块自动沿冰面拖动，电极与冰芯轴垂直对齐，间距为15毫米。根据电场强度与到电极的距离成反比的物理原理，电极的有效分辨率约等于电极间距（15毫米），该间距内约65%的电力线会穿过。本次测量温度为-20℃。 2015年，Fujita、Parrenin等（2015）通过火山层同步法，对两座分别钻取于南极偏远穹顶之巅的深冰芯——富士穹顶（DF）冰芯与EPICA Dome C（EDC）冰芯——进行了定年校准，以深化对两者年代序列的认知。该研究使用了DF2冰芯深度范围875~2200米区间内的ECM数据。本次我们将该数据集公开共享。 本数据集包含两类深度信息：第一列为DF2冰芯的实际深度；第三列为转换为DF1冰芯等效深度的DF2冰芯深度；第二列为电极间的电流值。需注意，本版本数据未进行额外的噪声清理操作，仅完成了每10毫米的滑动平均处理，因此仍属于原始数据范畴。