Ice core dating by the use of seasonal change of chemical elements concentration

1995年，在日本新泻县Saiho的仲冬至初春期间，用一系列积雪样品观察了各种化学元素浓度的时间演变。在这次观测中发现，即使在雪融化季节开始后的湿变质作用下，雪中的离子浓度、颗粒浓度和同位素比等化学元素的浓度仍被保存在积雪中。1996年，利用南极、北极和亚洲高原地区的冰芯，分析了这些元素的变化剖面。通过计算这些元素浓度的年周期，尝试了岩心的测年，并与其他方法的测年结果进行了比较。结果表明，无论是未经历熔融的极地岩心，还是经历夏季熔融的亚洲高地岩心，这种计数方法都能提供合理的年龄。结果表明，无论是极地冰芯还是非极地冰芯，计算冰芯的年层数都是一种有用的工具。

In 1995, the time evolution of the concentration of various chemical elements has beem observed with series of samples taken from a snow pack in a period of mid-winter to early spring at Saiho, Niigata Prefecture, Japan. In this observation, it was found that the concentration of the chemical elements such as ion concentration, particle concentration and isotope ratio has been preserved within the snow pack even with the wet metamorphism of snow after the snow melting season started.In 1996, Vartical profiles for these elements have been analyzed with ice cores retrieved at Antarctic, Arctic and Asian highland regions. The dating of the cores has been tried by counting the annual cycle of the concentration of these elements, and compared with the dating results made by the other methods. It was found that the counting method would provide reasonable age for both the polar cores which has experienced no melting and Asian highland cores which has been subjected to summer melting. It is concluded that counting annual layrs is a useful tool to date ice cores either from polar or non-polar regions.