在山区的岩喷射会产生流量备份和过度淹水
Annie Borch1, Thomas J Jones2, James K Russell1
1Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, BC Canada.
概括
在山地地形中,火山岩流的收缩可能会导致显著的备份. 这种备份受到岩粘度和流速的影响,通过扩大洪水区域和持续时间,增加了危险风险.
科学领域:
- 地质地质地质地质地质地
- 火山学 火山学是一门学科.
- 流体动力学 流体动力学
背景情况:
- 火山爆发经常发生在高地形地形上,但山地形对岩排放的影响仍然不太清楚.
- 了解复杂地形中的岩流行为对于危险评估和缓解策略至关重要.
研究的目的:
- 调查在狭窄的火山地形中岩备份的机制和控制因素.
- 量化流体特性,地形约束和岩备份大小之间的关系.
主要方法:
- 在受控实验室实验中使用模拟材料 (糖,糖醇) 模拟岩喷射.
- 系统地改变流体粘度,体积流量,通道宽度和斜率以观察备份动态.
- 将实验发现扩展到自然的火山系统.
主要成果:
- 岩的备份大小与高体积流量,高粘度和狭窄的收缩正相关.
- 斜坡对备份的影响是由粘度调节的:的斜坡在高粘度 (~50Pa·s) 时加剧备份,而浅的斜坡在低粘度 (~1.5Pa·s) 时这样做.
- 确定了岩备份的三个主要原因:障碍物流相互作用,收缩引起的流失平衡,以及由于关键流转而导致的流失平衡.
结论:
- 狭窄的地形显著增加了岩流对备份的易感性.
- 岩后备会导致上游淹水增加和下游溢出延长,从而扩大危险区域和持续时间.
- 这些发现提高了我们对山区火山风险的理解,并为靠近活火山的社区进行风险评估提供了信息.
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