Volcanic Record in Antarctic Ice

该奖项支持一个项目，开发和完善分析技术，以表征和确定火山灰或火山灰的日期，火山灰通常存在于大冰盖的冰芯中。 冰盖中的火山岩层特别有价值，因为如果它们来自大规模喷发，它们会形成独特的时间地层标志。 火山灰的化学成分可以用来确定物质的来源或起源，40 Ar/39 Ar测年法有可能提供该层的绝对年龄。 然而，由于火山灰层中的物质数量非常少，无论是在总质量还是在颗粒大小方面，重要的是要开发适当的分析技术，可以成功地表征和测定小样品的日期。 在同位素分析之前改进用于氩提取的激光聚变技术是一个重大挑战。 然而，如果成功的话，这项工作将对冰芯作为一种独立的测年工具的研究有很大的好处。 此外，冰芯火山灰的特征和定年将为气候模型提供重要信息。

This award supports a project to develop and refine analytical techniques to characterize and date volcanic ash, or tephra, that is often found in ice cores from large ice sheets. Tephras layers in ice sheets are particularly valuable because, if they are from large eruptions, they form unique time-stratigraphic markers. The chemistry of the tephra can be used to determine the provenance, or origin, of the material and 40Ar/39Ar dating has potential to provide an absolute age of the layer. However, because the amount of material in tephra layers is very small, both in total mass and in terms of particle size, it is important to develop appropriate analytical techniques that can successfully characterize and date small samples. Refinement of the laser fusion technique for argon extraction prior to isotopic analysis of is a significant challenge. However, if successful, this work would be a substantial benefit to studies of ice cores as an independent dating tool. Furthermore, characterization and dating of tephra from ice cores will provide important information to climate models.