Estimation of lahar flow velocity on Popocatepetl volcano (Mexico)
Estimation of lahar flow velocity on Popocatepetl volcano (Mexico)
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DOI：
10.1016/j.geomorph.2007.02.011
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发表时间：
2007-11-15
期刊：
影响因子：
3.9
通讯作者：
Castillo-Rodriguez, M.
中科院分区：
文献类型：
--
作者：
Munoz-Salinas, E.;Manea, V. C.;Castillo-Rodriguez, M.
1997年和2001年期间，在墨西哥波波卡特佩特尔火山东北段的特内内潘科和惠洛亚克峡谷发生了两次拉哈尔。这些火山口是火山活动的结果，火山活动的特点是火山碎屑的下降和流动。拉哈尔火山是由火山喷发数小时后产生的大规模故障引发的。在这类研究中常用的著名超高技术被用来推断冰川的平均速度。估算结果表明，流速的大范围为1.3-13.8m/S，取决于以下地貌参数：河道深度和坡度、洪峰流量和距初始源的距离。这些结果与圣海伦斯山(1980)和内瓦多德尔鲁伊斯(1985)用同样的超高技术获得的熔岩速度进行了比较。根据数据，来自内华多德尔鲁伊斯和波波卡特佩特尔的拉哈尔火山是由类似的条件触发的，而在圣海伦斯山，它们是火山碎屑涌动云转化的结果。事实上，圣海伦斯拉哈斯火山的速度几乎是内华多德尔鲁伊斯和波波卡特佩特尔的两倍。这一观察表明了火山碎屑形成的重要性，因为火山碎屑涌动云比火山碎屑坠落产生的火山碎屑更快。在活火山附近社区的火山灰风险评估研究中应考虑到这些结果。(C)2007 Elsevier B.V.保留所有权利。
During 1997 and 2001 two lahars took place in the Tenenepanco and Huiloac gorges on the northeastern sector of the Popocatepetl volcano in Mexico. These lahars were the result of volcanic activity characterized by a pyroclastic fall and flow. The lahars were triggered by the mass failures produced hours after the eruption. The well-known superelevation technique commonly used in this kind of study was applied to infer the lahar's mean velocity. Estimations show a broad flow velocity range of 1.3-13.8 m/s depending on the following geomorphological parameters: channel depth and slope, peak discharge and distance from the initial source. These results were compared with lahar velocities from Mount St Helens (1980) and Nevado del Ruiz (1985), which were obtained by the same superelevation technique. According to the data, the lahars from Nevado del Ruiz and Popocatepetl were triggered by similar conditions, while at Mount St Helens they were the result of the conversion of a pyroclastic surge cloud. Actually, the Mount St Helens lahars were almost twice as fast as the ones at Nevado del Ruiz and Popocatepetl. This observation shows the importance of the lahars' genesis in that the pyroclastic surge clouds produce faster lahars than do pyroclastic falls. Such results should be taken into account in lahar risk assessment studies for communities located near active volcanoes. (c) 2007 Elsevier B.V. All rights reserved.