Multi-Phased Flow Modeling of Vulcanian Explosions with Fountain Collapse on Montserrat

蒙特塞拉特火山喷泉塌陷的 Vulcanian 爆炸的多相流模拟

• 批准号: 0073761
• 负责人: Barry Voight
• 金额: $ 15.02万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-15 至 2004-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0073761&HistoricalAwards=false
• 关键词: Multi; Phased; Flow; Modeling; Vulcanian

VoightEAR-0073761Numerous short-duration explosions occurred during August, September and October 1997, at the Soufriere Hills Volcano, Montserrat, West Indies. These eruptions were accompanied by gravity collapse of heavy parts of the eruption column, that produced pumice and ash flows (pyroclastic flows) and "ash hurricanes" that moved sideways, into adjacent farmlands and formerly populated areas. Many of these eruptions were predicted, and we and other staff of Montserrat Volcano Observatory closely documented the eruptions by continuous seismic monitoring, measured surveys of the eruption clouds,photography, and video. Such data are rare, and in this project, we aim to quantify these eruptions, including the speed and trajectory of the explosion clouds, and then to compare these field-based data to sophisticated models of the eruptions. In our modeling, we will attempt to identify the magma and gas ratios in the eruption conduit before the explosion, and the pressure distribution. Then we will use this information as the starting condition for a "multi-phase" explosion model, in which separated solid and gas phases are allowed to expand dynamically upon release from the conduit tube. We can track the speeds and trajectories of the particles emitted from the conduit, and the particle densities of theerupting particle-and-gas cloud. We hope from this study to establish the main conditions in the conduit that control whether the clouds will continue to rise vertically, or will collapse to form dangerous pyroclastic flows. Pyroclastic flows are the major cause of loss of life in explosive eruptions worldwide, and the improved understanding obtained from this project should help to reduce hazards at a number of locations in this country and abroad.

VoightEAR-0073761 1997年8月、9月和10月在西印度群岛蒙特塞拉特的苏弗里尔山火山发生了大量的短期爆炸。这些喷发伴随着喷发柱沉重部分的重力坍塌，产生了浮石和火山灰流动(火山碎屑流动)和侧向移动到邻近农田和以前居住的地区的“火山灰飓风”。我们和蒙特塞拉特火山观测站的其他工作人员通过持续的地震监测、对喷发云的测量、摄影和视频，密切记录了这些喷发。这样的数据很少见，在这个项目中，我们的目标是量化这些喷发，包括爆炸云的速度和轨迹，然后将这些基于现场的数据与复杂的喷发模型进行比较。在我们的模拟中，我们将尝试确定爆炸前喷发管道中的岩浆和气体比率，以及压力分布。然后，我们将使用这些信息作为“多相”爆炸模型的起始条件，在该模型中，分离的固体和气相在从管道中释放时被允许动态膨胀。我们可以跟踪从管道中发射的粒子的速度和轨迹，以及喷发的粒子和气体云的粒子密度。我们希望通过这项研究来确定管道中控制云层是否会继续垂直上升，还是会坍塌形成危险的火山碎屑流的主要条件。火山碎屑流是世界各地爆炸性喷发造成生命损失的主要原因，从该项目中获得的更好的了解应有助于减少该国和国外许多地点的危险。