Understanding Controls on the Scale and Style of Explosive Volcanic Eruptions with Observational and Multi-Phase Computational Techniques

利用观测和多相计算技术了解对火山喷发规模和类型的控制

• 批准号: 0310329
• 负责人: Amanda Clarke
• 金额: $ 25万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0310329&HistoricalAwards=false
• 关键词: Understanding; Controls; Scale; Style; Explosive

EAR-0310329ClarkePopulation density around active volcanoes has increased rapidly over the last century, and in fact, roughly 500 million people today live in regions of the world directly threatened by volcanic hazards. Pyroclastic flows, or hot, high-speed avalanches of pumice and gas, are a major cause of destruction and loss of life in explosive eruptions. Their effects can be extremely destructive, as indicated by the deaths of 27,000 inhabitants of St. Pierre (Martinique) in 1902, the devastating eruption of Lamington (Papua New Guinea) in 1951, and the eruptions of Merapi (Indonesia) in the last century. Similar impacts can be anticipated in the future at other volcanically active locations. Two of the most important eruptions of the last 20+ years, with respect to monitoring, hazards mitigation and post-eruptive research, have been the eruptions of Mount St. Helens (MSH) during the 1980's and the ongoing eruption of the Soufriere Hills volcano, Montserrat (SHV). Each of these volcanoes, at different times during a single eruptive period, exhibited two different scales and styles of explosion - one style aborting after only a few minutes, generating what are termed Vulcanian explosions, and the other style continuing rather than aborting, thus producing larger-scale, sustained Plinian eruptions. The controls on such explosions are poorly understood, are imperative to hazard mitigation and are therefore the focus of the proposed research. Our previous studies successfully compared observational and field data from Vulcanian explosions at SHV with conduit and explosion models, validating our computational methods. The proposed research will build on this work in order to identify the salient controls on explosive style in two ways. First, because our previous studies required several simplifying assumptions, we intend to further develop the conduit flow model allowing for increased complexity of the magmatic system. Second, we will analyze explosions of different scales and styles: the 1996 sustained, sub-Plinian explosion at SHV and a series of short-lived eruptions at MSH, in July and August 1980. Our improved model combined with field-based studies of real explosions will lead to a better understanding of the potential impact of such volcanic eruptions.

在上个世纪，活跃火山周围的EAR-0310329克拉尔挤压密度迅速增长，实际上，如今大约有5亿人生活在直接受到火山危险威胁的世界各地。火山碎屑流，或热的高速雪崩，是爆炸性喷发中破坏和生命损失的主要原因。正如1902年27,000名圣皮埃尔（马提尼克岛）的死亡所表明的那样，它们的影响可能是极具破坏性的，1951年，拉明顿（巴布亚新几内亚）的毁灭性爆发以及上个世纪的默拉皮（印度尼西亚）爆发。 将来在其他火山活动的地点将来可能会产生类似的影响。 关于监测，缓解危害和爆发后研究，过去20多年中最重要的两次爆发是1980年代的圣海伦斯山（MSH）的喷发，以及蒙特塞拉特（SHV）的Soufriere Hills Volcano的持续喷发。 这些火山中的每一个在一次爆发时期的不同时间都表现出了两种不同的鳞片和风格的爆炸风格 - 一种风格仅几分钟后流产，产生了所谓的瓦肯尼亚爆炸，而另一种风格则持续而不是流产，而不是流产，因此产生了较大的plinian plinian爆发。 关于此类爆炸的控制知之甚少，对缓解危害至关重要，因此是拟议研究的重点。 我们以前的研究成功地将SHV的Vulcanian爆炸中的观察性和现场数据与导管和爆炸模型进行了比较，从而验证了我们的计算方法。 拟议的研究将以这项工作为基础，以通过两种方式确定爆炸风格的显着控制。 首先，由于我们以前的研究需要几个简化的假设，因此我们打算进一步开发导管流模型，以提高岩浆系统的复杂性。 其次，我们将分析不同尺度和样式的爆炸：1996年在SHV上持续的，替代的次级爆炸以及1980年8月在MSH举行的一系列短暂的爆发。我们的改进模型与实地爆炸的改进模型相结合，将对这种燃烧的潜在影响有更好的了解。