Shock wave hazards during explosive volcanic eruptions: an experimental investigation

火山喷发期间的冲击波危害：实验研究

• 批准号: 213034968
• 负责人: Dr. Teresa Scolamacchia
• 金额: --
• 依托单位: Sektion Mineralogie, Petrologie und Geochemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/213034968?language=en
• 关键词: Shock; wave; hazards; during; explosive

Shock waves in explosive volcanic eruptions are poorly investigated. Several issues concerning their generation and propagation are still objects of great debate, and the associated hazards are currently downplayed in active volcanic area risk assessment. Evidence for such phenomena was recently recovered from one of the villages destroyed by the 1982 eruption of El Chichón volcano (Mexico). Micrometric craters produced by the impact of volcanic ash particles were found on the surface of a steel pole. The velocities of the impacts, was calculated by analytical methods as up to 980 m/s, similar to those reported theoretically and numerically for shock waves accompainying volcanic eruptions. The main goal of this proposal is to gain better insight into the mechanisms by which volcanic particles of different size/mass can be accelerated by shock waves, either given efficient momentum coupling with a gas phase or due to changes in the shock structure at the contact with particles. We plan to reproduce experimentally the impact craters on metal targets. Questions to be answered are: 1) What is the main process responsible for particle acceleration in the presence of shock waves? 2) What is the relationship between the grain-size, the mass load, the shape of the particles, and the high velocities calculated? 3) Is the steel’s temperature at the moment of impact an important factor in determining the magnitude of “cratering”? The results expected from this investigation, will 1) elucidate the processes associated with shock wave propagation during explosive eruptions, and 2) help to raise awareness about the hazards related to these phenomena while improving specific response strategies.

爆炸性火山爆发中的冲击波很少。关于它们的一代和传播的几个问题仍然是激烈辩论的对象，目前在活动的火山区风险评估中淡化了相关的危害。最近，从1982年的埃尔奇琴火山（ElChichónVolcano）（墨西哥）爆发的村庄中回收了这种现象的证据。在钢杆表面发现了由火山灰颗粒的影响产生的微米陨石坑。通过分析方法计算的影响速度最多980 m/s，类似于所报道的理论和数值的冲击波，用于发生火山喷发的冲击波。该提案的主要目标是更好地深入了解不同尺寸/质量的火山颗粒可以通过冲击波加速的机制，这是给定有效的动量与气相耦合的，或者是由于与颗粒接触时的冲击结构变化。我们计划通过实验重现金属靶标的撞击弹药。要回答的问题是：1）在存在冲击波的情况下负责粒子加速的主要过程是什么？ 2）晶粒大小，质量负载，颗粒的形状和计算高速度之间的关系是什么？ 3）冲击时钢的温度是否是确定“碎屑”大小的重要因素？这项投资预期的结果将1）阐明在爆炸过程中与冲击波传播相关的过程，以及2）帮助提高人们对与这些现象相关的危害的认识，同时改善特定的响应策略。