Thermal, acoustic and seismic signals from pyroclastic density currents and Vulcanian explosions at Soufriere Hills Volcano, Montserrat
Thermal, acoustic and seismic signals from pyroclastic density currents and Vulcanian explosions at Soufriere Hills Volcano, Montserrat
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DOI：
10.1144/m39.9
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发表时间：
2014-01-01
期刊：
影响因子：
--
通讯作者：
Stewart, R.
中科院分区：
文献类型：
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作者：
Delle Donne, D.;Ripepe, M.;Stewart, R.
我们展示了两个例子，说明如何综合分析热和次声信号，可以用来获得，在真实的时间，火山活动的信息。蒙特塞拉特的苏弗里埃山火山（SHV）提供了研究与熔岩丘活动有关的各种过程的机会，如火山碎屑密度流和火山大爆发。次声和热分析用于约束PDC的传播和它们的速度，在这里计算的范围在15和75 m s（-1）之间。在2010年2月5日的火山爆发期间，次声和热记录使我们能够确定一个大约13秒的地震前兆，可能与爆炸开始前管道的加压有关。相关的甚长周期（VLP）地震信号与热成像检测到的气体推力相关联，并可能反映了由质量排放引起的向上动量的变化。此外，根据次声和热分析，我们估计气体推力阶段持续22 s，初始羽流速度约为170 m/s（-1），平均体积排放率为0.3 x 10（5）-9.2 x 10（5）m（3）s（-1）。这种信息提供的真实的时间为模拟火山灰扩散到大气中提供了重要的输入参数。
We show two examples of how integrated analysis of thermal and infrasound signal can be used to obtain, in real time, information on volcanic activity. Soufriere Hills Volcano (SHV) on Montserrat offers the opportunity to study a large variety of processes related to lava-dome activity, such as pyroclastic density currents (PDCs) and large Vulcanian eruptions. Infrasound and thermal analysis are used to constrain the propagation of PDCs and their velocities, which are calculated here to range between 15 and 75 m s(-1). During the Vulcanian eruption of 5 February 2010, infrasound and thermal records allow us to identify an approximately 13 s seismic precursor possibly related to the pressurization of the conduit before the explosion onset. The associated very long period (VLP) seismic signal is correlated with the gas-thrust phase detected by thermal imagery, and may reflect a change in the upward momentum induced by the mass discharge. Moreover, from infrasound and thermal analysis, we estimate a gas-thrust phase lasting 22 s, with an initial plume velocity of approximately 170 m s(-1) and a mean volumetric discharge rate of 0.3 x 10(5)-9.2 x 10(5) m(3) s(-1). This information provided in real time gives important input parameters for modelling the tephra dispersal into the atmosphere.