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.

EAR-0310329Clarke 活火山周围的人口密度在上个世纪迅速增加，事实上，当今世界上大约有 5 亿人生活在直接受到火山灾害威胁的地区。火山碎屑流，或浮石和气体的高温高速雪崩，是爆炸性喷发造成破坏和人员伤亡的主要原因。它们的影响可能具有极大的破坏性，1902 年圣皮埃尔（马提尼克岛）27,000 名居民的死亡、1951 年拉明顿（巴布亚新几内亚）毁灭性的喷发以及上个世纪默拉皮（印度尼西亚）的喷发就表明了这一点。 。 预计未来其他火山活跃地点也会产生类似的影响。 过去 20 多年来，在监测、减灾和喷发后研究方面最重要的两次喷发是 1980 年代的圣海伦斯火山 (MSH) 喷发和正在进行的苏弗里耶尔火山喷发，蒙特塞拉特（SHV）。 这些火山中的每座火山，在一次喷发期间的不同时间，都表现出两种不同规模和风格的爆炸——一种风格仅在几分钟后中止，产生所谓的瓦肯式爆炸，另一种风格继续而不是中止，从而产生更大规模、持续的普林尼式喷发。 人们对此类爆炸的控制知之甚少，这对于减轻危险至关重要，因此是拟议研究的重点。 我们之前的研究成功地将 SHV 火山爆炸的观测数据和现场数据与管道和爆炸模型进行了比较，验证了我们的计算方法。 拟议的研究将以这项工作为基础，以便通过两种方式确定对爆炸性风格的显着控制。 首先，由于我们之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，以增加岩浆系统的复杂性。 其次，我们将分析不同规模和类型的爆发：1996 年 SHV 的持续亚普林尼式爆发以及 1980 年 7 月和 8 月 MSH 的一系列短暂爆发。我们改进的模型结合了真实的现场研究爆炸将有助于更好地了解此类火山喷发的潜在影响。