Relative partitioning of acoustic and seismic energy during Strombolian eruptions
Relative partitioning of acoustic and seismic energy during Strombolian eruptions
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DOI：
10.1016/j.jvolgeores.2005.05.002
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发表时间：
2005-12-15
影响因子：
2.9
通讯作者：
Aster, RC
中科院分区：
文献类型：
--
作者：
Johnson, JB;Aster, RC
斯特龙博利式喷发期间的相对弹性能量分配可根据声压和地震波速记录来估算。我们概述了确定部署在喷发口几公里范围内的传感器的声能和地震能的方法。我们利用这些能量引入火山声 - 震比（VASR）的概念，它是通过大气传播和进入地球的弹性能量之比。喷发的VASR是对爆炸式脱气的一种物理诊断，适用于比较单个火山以及不同火山之间的喷发机制。在此，我们评估了卡里姆斯基火山和埃里伯斯火山离散的斯特龙博利式爆炸事件的声能和地震能以及相应的VASR。我们将埃里伯斯火山相对较高且稳定的VASR（η = 8，标准差41%）归因于在持续存在的熔岩湖表面出现的可重复的源条件，以及与大气的强耦合。卡里姆斯基火山较低且变化更大的VASR（1998年η = 0.18到1991年η = 1.51，标准差分别为93%和313%）归因于在狭窄且部分堵塞的管道内变化的条件。卡里姆斯基火山变化的地震 - 声能分配，如大的VASR标准差所示，表明影响VASR的管道条件，包括岩浆特性、管道堵塞或破碎深度，在爆炸过程中和连续事件之间都会发生变化。（c）2005爱思唯尔有限公司。保留所有权利。
The relative elastic energy partitioning during Strombolian eruptions can be estimated from acoustic pressure and seismic velocity records. We outline methods for determining acoustic and seismic energies for sensors deployed within several kilometers of erupting vents. We use these energies to introduce the concept of the volcano acoustic-seismic ratio (17, or VASR), which is the ratio of elastic energy propagated through the atmosphere and into the earth. Eruption VASR is a physical diagnostic of explosive degassing that is appropriate for comparing eruption mechanisms at individual and between various volcanoes. Here we assess acoustic and seismic energies and corresponding VASR for discrete Strombolian explosive events at Karymsky and Erebus Volcanoes. We attribute the relatively high and stable VASR at Erebus (eta = 8, standard deviation 41%) to repeatable source conditions occurring at the surface of a persistent lava lake, with accompanying strong coupling to the atmosphere. Lower and more variable VASR at Karymsky (eta = 0.18 in 1998 to eta = 1.51 in 1991, with standard deviations of 93% and 313%, respectively) is attributed to changing conditions within a narrow, partially choked conduit. Variable seismo-acoustic energy partitioning for Karymsky, as manifested by the large VASR standard deviation, suggests that conduit conditions affecting VASR, which include magma properties, conduit obstruction, or fragmentation depths can evolve both during the course of an explosion and between successive events. (c) 2005 Elsevier B.V. All rights reserved.