干旱区粉尘对古里雅冰帽中化学记录的影响  

INFLUENCE OF ARID DUST ON THE CHEMICAL RECORDS OF THE GULIYA ICE CAP

作　　者：李月芳[1] 姚檀栋[1] 盛文坤[1] 皇翠兰[1] 

机构地区：[1]中国科学院兰州冰川冻土研究所冰心与寒区环境开放研究实验室

出　　处：《海洋地质与第四纪地质》1999年第2期103-108,共6页Marine Geology & Quaternary Geology

基　　金：国家"九五"攀登项目

摘　　要：从雪冰样品中的阳离子（Ｃａ２＋、Ｎａ＋、Ｍｇ２＋和Ｋ＋）、阴离子（Ｃｌ－、ＳＯ４２－和ＮＯ３－）、ｐＨ值、电导率等几个方面分析了干旱区粉尘对古里雅冰帽中化学记录的影响特点。研究表明，干旱区粉尘对该冰帽的影响使得离子的浓度高于极地冰川中相应离子的浓度，离子之间的浓度大小顺序明显地不同于极地冰川。钻取样品中离子存在明显的空间变化趋势，反映了近源粉尘对冰帽中化学记录的影响；最新一次降水中离子没有明显的空间变化趋势，反映了远源粉尘对冰帽整体的均匀影响。８５％的样品的ｐＨ值大于７，部分样品的ｐＨ值大于９，归因于来自干旱区的尘埃中的易溶性弱酸盐的水解作用。By means of cations(Ca 2+ ,Na +,Mg 2+ and K +),anions(Cl -,SO 4 2- and NO 3 -),pH value and conductivity of snow and ice from the Guliya ice cap,the feature of arid dust influence on the cap is discussed in this paper.Because of influence of arid dust,the concentrations of all ions are higher than that of polar glaciers,and the concentration sequence of cations from high to low is Ca 2+ >Na +>K +>Mg 2+ ,which is obviously different from ocean type glaciers such as the Antarctic glacier,in which the order is Na +>Mg 2+ >Ca 2+ >K +.The concentrations of all anions are also higher than that of polar glaciers,with an order of anions SO 4 2- >Cl ->NO 3 -.The cations and anions,except Cl -,present a spatial trend in the samples as that the concentrations increase from the top to the margin of the cap,indicating the influence of arid dust coming from a not far area.But there is not an obvious trend of ions in the surface snow samples,indicating a uniform influence of arid dust coming from a long distance area.Changes of ion concentrations in surface snow samples reflect that they are not distributed uniformly in air.The pH values are in the range of 6 5～9 36,larger than 7 for 85% samples and more than 9 for some ones.All pH values are higher than that of background precipitation because of the large influence of arid dust containing soluble weak acid salts.Salt consisting of Ca 2+ or Mg 2+ has the largest influence on pH value because of its highest concentration and obvious correlation with pH value,and Na + and K + may occur as strong acid salts.The conductivity is also higher than that of the background precipitation and has an obvious correlation with pH value,because soluble salts in the dust

关 键 词：干旱区粉尘 阴离子 阳离子 古里雅冰帽 化学记录 

分 类 号：P343.63[天文地球—水文科学]