Eruption mass estimation using infrasound waveform inversion and ash and gas measurements: Evaluation at Sakurajima Volcano, Japan
Eruption mass estimation using infrasound waveform inversion and ash and gas measurements: Evaluation at Sakurajima Volcano, Japan
复制标题
DOI：
10.1016/j.epsl.2017.09.043
复制
发表时间：
2017-12-05
影响因子：
5.3
通讯作者：
Iguchi, Masato
中科院分区：
文献类型：
--
作者：
Fee, David;Izbekov, Pavel;Iguchi, Masato
喷发质量和质量流率是确定火山喷发物空中范围和危害的关键参数。次声波形反演是一种很有前途的量化火山喷发的技术。虽然地形可能会大大改变次声波形，因为它的传播，在波传播建模和台站覆盖率的进步允许强大的火山爆发的次声数据反演。在已知流量密度的情况下，反演可以估算喷发质量流量和喷发总质量。然而，次声为基础的喷发流量和质量估计尚未验证独立的测量，数值模拟最近才被应用到反演技术。在这里，我们提出了一个强大的全波形声波反演方法，并使用它来计算喷发流量和质量从49樱岛火山，日本爆炸。2015年2月12日至20日部署的六个次声站记录了爆炸。我们使用3-D时域有限差分建模和高分辨率数字高程模型计算数值绿色函数。反演，假设一个简单的声发射源，提供了现实的喷发群众和极好的适合大多数爆炸的数据。反演结果进行了比较，独立的喷发群众来自地面灰收集和火山气体测量。假设现实的流量密度，我们的次声派生的火山灰丰富的喷发质量比较有利的地面估计，协议范围从两个到一个数量级的因素。时间依赖的流密度和声传播的不一致可能导致方法之间的不匹配。我们的研究结果表明，现实和准确的次声为基础的喷发质量和质量流率的估计，可以使用这里所采用的方法计算。如果已知准确的火山流动参数，这种技术的应用可以广泛地应用于近实时计算喷发质量流率和总质量。这些火山喷发建模和监测的关键输入参数目前还没有。(C)2017作者（S）由爱思唯尔公司出版
Eruption mass and mass flow rate are critical parameters for determining the aerial extent and hazard of volcanic emissions. Infrasound waveform inversion is a promising technique to quantify volcanic emissions. Although topography may substantially alter the infrasound waveform as it propagates, advances in wave propagation modeling and station coverage permit robust inversion of infrasound data from volcanic explosions. The inversion can estimate eruption mass flow rate and total eruption mass if the flow density is known. However, infrasound-based eruption flow rates and mass estimates have yet to be validated against independent measurements, and numerical modeling has only recently been applied to the inversion technique. Here we present a robust full-waveform acoustic inversion method, and use it to calculate eruption flow rates and masses from 49 explosions from Sakurajima Volcano, Japan. Six infrasound stations deployed from 12-20 February 2015 recorded the explosions. We compute numerical Green's functions using 3-D Finite Difference Time Domain modeling and a high-resolution digital elevation model. The inversion, assuming a simple acoustic monopole source, provides realistic eruption masses and excellent fit to the data for the majority of the explosions. The inversion results are compared to independent eruption masses derived from ground-based ash collection and volcanic gas measurements. Assuming realistic flow densities, our infrasound-derived eruption masses for ash rich eruptions compare favorably to the ground-based estimates, with agreement ranging from within a factor of two to one order of magnitude. Uncertainties in the time-dependent flow density and acoustic propagation likely contribute to the mismatch between the methods. Our results suggest that realistic and accurate infrasound-based eruption mass and mass flow rate estimates can be computed using the method employed here. If accurate volcanic flow parameters are known, application of this technique could be broadly applied to enable near real-time calculation of eruption mass flow rates and total masses. These critical input parameters for volcanic eruption modeling and monitoring are not currently available. (C) 2017 The Author(s). Published by Elsevier B.V.