Research on the source volcanoes for micro-tephra gains in Antarctic ice sheet.

这项研究的目的是检验南极冰盖中微小的火山灰颗粒用于测年的可能性。以南极洲的H15冰芯为样本。结果表明：1.从形状和化学结构上，我们确认了~10μm尺寸的微米级火山灰尘的存在。H15冰芯中微火山喷发粒子数量与SO4~(2-)气溶胶浓度的对比表明：(1)一些世界性喷发同时释放出火山喷发粒子和SO2气体，(2)一些喷发喷发主要释放SO2气体，(3)一些喷发喷发主要释放火山喷发粒子。我们成功地对粒径为100μm的单一山雀花进行了LA/ICPMS分析。但在10μ时，微米级的非洲菊还没有完全形成。用仪器中子活化法分析了一些世界范围内的火山喷发热液中的微量元素含量。

Purpose of this research is to check a possibility of tephrochronological dating use of micro tephra particles in Antarctic ice sheet. The H15 ice core in Antarctica was used as sample.1. We recognized the existence of 〜10μm size of micro tephra particles from the shape and the chemistry.2. Comparison between the numbers of micro tephra partices and the concentration of SO_4^<2-> aerosol in H15 ice core indicates the types (ash type or gas type) that is (1) some of world wide eruptions release both tephra particles and SO_2 gas, (2) some of them release mainly SO_2 gas, and (3) some of them release mainly tephra particles.3. We succeeded LA/ICP-MS analysis for single tephra particle of 100μm size. But for 10μm size of micro tephra particles did not complete.4. Trace elements contents in some world wide eruption tephras were analyzed by instrumental neutron activation analysis.