Instability and Collapse of Pressurized Lava Domes: A Study of Triggering Mechanisms

加压熔岩穹顶的不稳定和倒塌：触发机制的研究

• 批准号: 9908590
• 负责人: Derek Elsworth
• 金额: $ 16.33万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-15 至 2005-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9908590&HistoricalAwards=false
• 关键词: Instability; Collapse; Pressurized; Lava; Domes

This project will study the explosive and hazardous disintegration of lava domes, observed at Soufriere Hills volcano and at Merapi volcano, that is hypothesized to result from gaseous overpressurization of the dome core. Explosive failure is typically delayed hours to days from the initial core pressurization event, suggesting the role of outward gas pressure-diffusion in triggering failure. Diffusing gas over-pressures inititate spalling of the dome periphery, that ultimately transects close to the dome core, resulting in the explosive release of core pressure, and the potential development of pyroclastic flows. This study will examine the interplay between gas transport and mechanical behavior within the dome interior, defining fluid and thermal diffusion rates, and ultimately providing the necessary constraint to effective-stress models of stability, including those representing progressive and retrogressive failure. This study will examine the progressive collapse of lava domes, define the interplay of pressure-diffusive and thermal transport in defining strength loss, define the time-scales over which the pressurization operates, delineate potential precursors to collapse, and offer an evaluation of the potential for collapse prediction.

该项目将研究在苏弗里埃山火山和默拉皮火山观察到的熔岩圆顶的爆炸性和危险性解体，据推测，这是圆顶核心气体超压造成的。 爆炸失效通常从最初的堆芯增压事件延迟数小时到数天，这表明向外气体压力扩散在触发失效中的作用。 扩散气体超压引发圆顶周边的剥落，最终在圆顶核心附近横切，导致核心压力的爆炸性释放，以及火山碎屑流的潜在发展。 本研究将研究气体传输和圆顶内部的力学行为之间的相互作用，定义流体和热扩散速率，并最终提供必要的约束，有效应力模型的稳定性，包括那些代表渐进和倒退失败。 这项研究将检查熔岩圆顶的渐进式崩溃，定义的压力扩散和热传输的相互作用，在定义强度损失，定义的时间尺度上的加压操作，描绘潜在的前兆崩溃，并提供一个潜在的崩溃预测的评估。