Seismological Determination of Mass Ejection Rates of Explosive Eruptions

9903085 Kanamori本项目的主要目标是开发方法，通过将流体力学模型与地震数据相结合，直接测量火山爆发中喷出的质量作为时间的函数。 第二个目标是利用测量的物质喷射率来研究火山爆发的启动过程。 要研究的火山爆发包括：（1）1964年堪察加半岛的Shiveluch火山爆发;（2）1997年夏季堪察加半岛Karymsky火山爆发，这方面有高质量的数字数据;（3）圣海伦斯火山的小规模爆发，持续了整个1980年;（4）日本浅间山的几次火山爆发;（5）菲律宾皮纳图博火山1991年的火山爆发。 从这项研究中获得的信息将对火山爆发的特点提供限制，对量化火山灾害也很重要。 例如，测得的质量喷射率将对喷发的动力学模型提供直接约束。 在圣海伦斯山，与后来的事件相比，爆炸具有异常大的质量通量。 这一区别可能澄清爆炸的区别特征，并有助于解释爆炸的毁灭性影响。

9903085 Kanamori The main objective of this project is to develop methods to directly measure the ejected mass in volcanic eruptions as a function of time by combining a fluid mechanical model with seismological data. A secondary goal is to use the measured mass ejection rate to study the initiation process of volcanic eruptions. The eruptions to be studied include 1) the 1964 Shiveluch eruption in Kamchatka; 2) eruptions at Karymsky, Kamchatka, during the summer of 1997, for which high quality digital data are available; 3) small eruptions of Mount St. Helens which continuied throughout 1980; 4) several erutpions of mount Asama, Japan; and 5) the 1991 eruption of Mount Pinatubo in the Philippines. The information obtained from this study will provide constraints on the characteristics of volcanic eruptions and will also be important for quantifying volcanic hazards. For example, the measured mass ejection rate will provide a direct constraint on dynamical models of an eruption. At Mount St. Helens, the blast had an exceptionally large mass flux compared to later events. This difference may clarify the distinguishing features of blasts and help account for their disproportionally devastating effects.