A global study of volcanic infrasound characteristics and the potential for long-range monitoring
A global study of volcanic infrasound characteristics and the potential for long-range monitoring
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DOI：
10.1016/j.epsl.2011.08.027
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发表时间：
2011-10-15
影响因子：
5.3
通讯作者：
Phillips, J. C.
中科院分区：
文献类型：
--
作者：
Dabrowa, A. L.;Green, D. N.;Phillips, J. C.
火山爆发产生的次声可以在S 1000公里的距离内探测到，并经常被记录在国际监测系统的次声网络上。虽然之前已经对个别火山产生的次声进行了研究，但次声特征和喷发参数之间更一般的关系仍然不清楚。因此，使用一个包含全球39个分布的火山的110个事件的数据集，我们评估了IMS监测偏远火山的能力，并调查火山次声是否在一系列喷发类型和强度上表现出一致的趋势。测量了火山次声的声压幅值和频率含量，并计算了声能。将这些数据与每个事件的最大探测距离与该事件报告的最大羽流高度进行比较，该最大羽流高度被用作事件强度的替代。在调查的事件中，62%是由至少一个次声波监测站探测到的。探测到事件的最大距离通常随着羽流高度的增加而增加，2005年1月巴布亚新几内亚玛纳姆火山喷发时产生的次声在10 671公里的距离处探测到，该喷发产生的羽流在山顶上方20多公里处升起。总声能和声压幅度(经几何扩展校正)随羽流高度增加而增加，而火山次声的最低频率则减少。此外，次声特征和喷发羽流高度之间的关系表明，仅对这些数据的分析就可以限制对其他未观测到的喷发的羽流高度的重要估计。综上所述，这些调查结果表明，如果今后为此目的提供IMS次声网络，则可以通过探测和确定偏远火山的喷发特征来补充现有的监测技术，这些火山往往没有当地的监测网络。(C)2011爱思唯尔B.V.保留所有权利。
Volcanic infrasound from explosive eruptions is detectable at distances up to 1000 s of km and is often recorded on the International Monitoring System (IMS) infrasound network. Though infrasound produced by individual volcanoes has previously been studied, more general relationships between infrasound characteristics and eruption parameters remain unclear. Therefore, using a dataset comprising 110 events at 39 globally distributed volcanoes, we assess the ability of the IMS to monitor remote volcanoes and investigate whether volcanic infrasound exhibits consistent trends across a range of eruption styles and intensities. Acoustic pressure amplitude and frequency content of the volcanic infrasound were measured, and acoustic energy was also calculated. These were compared, along with the maximum distance of detection for each event, to the maximum plume height reported for the event, which was used as a proxy for event intensity. Of the events investigated 62% were detected by at least one infrasound station. The maximum distance at which an event was detected generally increased with the plume height, and infrasound produced during the eruption of Manam, PNG in January 2005, which produced a plume which rose over 20 km above the summit, was detected at a distance of 10,671 km. Total acoustic energy and acoustic pressure amplitude (corrected for geometrical spreading) increased with plume height, whilst the lowest frequency present in the volcanic infrasound decreased. Additionally, relationships seen between infrasound characteristics and eruption plume height indicate that analyses of this data alone could constrain vital estimates of plume heights for otherwise un-observed eruptions. Taken together these findings indicate that if made available for this purpose in the future, the IMS infrasound network could complement existing monitoring techniques by detecting and characterising eruptions at remote volcanoes which often have no local monitoring networks. (C) 2011 Elsevier B.V. All rights reserved.