A role of large-scale volcanism in global environmental changes

1.编制了第四纪大规模火山喷发的火山灰表。它覆盖了日本、新西兰、北美、欧洲、东非和东南亚等火山地区。该火山碎屑数据库包括火山碎屑形成矿物的岩相学特征、测年结果、在海洋同位素阶段中的地层位置、分布、体积等。这对于对比和鉴定在偏远地区观察到的火山碎屑以及理解大规模火山喷发在控制全球气候变化中的作用是有用的。边界阶段3/2和5a/4分别以Aira-Tn和Taupo-Kawakawa火山喷发和Toba火山喷发为特征。这一巧合强烈地表明，这些气候火山活动可能引起或促进了快速冷却。3.从南极冰芯中确定了最近200年的火山信号。特别是1809和1815信号非常突出。后者是坦博拉火山大喷发的产物，但前者的源火山尚未确定，推测在南半球。4.用非冰期的纹状年代学测定了产生几个标志火山灰（如Kikai-Akahoya和Ulreung-Oki火山灰）的大规模火山喷发的日历年龄。

1.A worldwide tephra catalog is compiled for the Quaternary large-scale explosive eruptions. It covers such volcanic regions as Japan, New Zealand, North America, Europe, East Africa, and Southeast Asia. This tephra database includes petrographic characters of tephra-forming minerals, dating results, stratigraphic position in the marine isotope stages, distribution, volume, etc. This must be useful for correlation and identification of tephra observed in remote areas as well as for understanding of a role of large-scale eruptions in controlling global climatic changes.2.Of several marked transition stages in climate recorded in marine isotope fluctuations, border stages 3/2 and 5a/4 are characterized by such large explosive volcanisms as Aira-Tn and Taupo-Kawakawa tephras, and Toba tephra, respectively. This coincidence strongly suggests that rapid cooling may have induced or accerelated from these climactic volcanisms.3.The last 200-years long volcanic signals are determined from ice core of Antarctica. In particular, the 1809 and 1815 signals are prominent. The latter is a product of the great Tambora eruption, but the source volcano of the former has not yet been determined, presumably in the southern hemisphere.4.A non-glacial varved chronology is applied for determining calendar age of large scale eruptions producing several marker tephras such as Kikai-Akahoya and Ulreung-Oki ashes.