PYROCLASTIC ERUPTIONS OF MOUNT ST. HELENS ON MAY 18, 1980

火山碎屑沉积是由马鞍山火山喷发形成的。1980年5月18日的圣海伦斯是克里斯韦尔博士几年来集中研究的主题。在美国地质调查局和其他学术研究人员的合作下，他和PI绘制了一个三维地层和相网络，并将其与由时间间隔定义的六个喷发阶段进行了对比。化学和地震数据表明，两种岩浆类型(白色和灰色)从一个7公里长的分区岩浆室喷发。喷发物质的这些变化与喷发机制的变化以及喷发前洞穴内岩浆成分的空间差异有关。“这项裁决将使克里斯韦尔能够继续进行这些研究，这些研究可能对预测圣海伦斯山和类似火山未来的喷发具有重要影响。

The pyroclastic deposits erupted by Mt. St. Helens on May 18, 1980 have been the subject0of intensive study by C. W. Criswell, a PhD student, for the last several years. With the cooperation of the USGS and other academic researchers, he and the PI have mapped a three-dimensional stratigraphic and facies network and correlated it with six eruptive phases, defined by time interval. Chemical and seismic data suggest that two magma types (white and gray) erupted from a zoned magma chamber seven km. deep, and that these changes in the eruptive materials relate to changes in the mechanism of eruption, as well as spatial differences in the magma composition within the chamber prior to eruption." This award will enable Criswell to continue these studies which could have important imlications for predicting future eruptions at Mt. St. Helens and similar volcanoes.