气候变化领域集成服务门户(CCPortal): Investigating Spectral Distortion of Local Volcano Infrasound by Nonlinear Propagation at Sakurajima Volcano, Japan

CCPortal

DOI	10.1029/2019JB018284
	Investigating Spectral Distortion of Local Volcano Infrasound by Nonlinear Propagation at Sakurajima Volcano, Japan
	Maher S.P.; Matoza R.S.; de Groot-Hedlin C.D.; Gee K.L.; Fee D.; Yokoo A.
发表日期	2020
ISSN	21699313
卷号	125 期号:3
英文摘要	Sound waves generated by erupting volcanoes can be used to infer important source dynamics, yet acoustic source-time functions may be distorted during propagation, even at local recording distances ((Formula presented.) 15 km). The resulting uncertainty in source estimates can be reduced by improving constraints on propagation effects. We aim to quantify potential distortions caused by wave steepening during nonlinear propagation, with the aim of improving the accuracy of volcano-acoustic source predictions. We hypothesize that wave steepening causes spectral energy transfer away from the dominant source frequency. To test this, we apply a previously developed single-point, frequency domain, quadspectral density-based nonlinearity indicator to 30 acoustic signals from Vulcanian explosion events at Sakurajima Volcano, Japan, in an 8-day data set collected by five infrasound stations in 2013 with 2.3- to 6.2-km range. We model these results with a 2-D axisymmetric finite-difference method that includes rigid topography, wind, and nonlinear propagation. Simulation results with flat ground indicate that wave steepening causes up to (Formula presented.) 2 dB (1% of source level) of cumulative upward spectral energy transfer for Sakurajima amplitudes. Correction for nonlinear propagation may therefore provide a valuable second-order improvement in accuracy for source parameter estimates. However, simulations with wind and topography introduce variations in the indicator spectra on order of a few decibels. Nonrandom phase relationships generated during propagation or at the source may be misinterpreted as nonlinear spectral energy transfer. The nonlinearity indicator is therefore best suited to small source-receiver distances (e.g., (Formula presented.) 2 km) and volcanoes with simple sources (e.g., gas-rich strombolian explosions) and topography. © 2020. American Geophysical Union. All Rights Reserved.
英文关键词	nonlinear propagation; Sakurajima; volcano infrasound
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187924
作者单位	Department of Earth Science and Earth Research Institute, University of California, Santa Barbara, CA, United States; Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, United States; Department of Physics and Astronomy, Brigham Young University, Provo, UT, United States; Wilson Alaska Technical Center, Alaska Volcano Observatory, Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, United States; Aso Volcanological Laboratory, Institute for Geothermal Sciences, Graduate School of Science, Kyoto University, Kumamoto, Japan
推荐引用方式 GB/T 7714	Maher S.P.,Matoza R.S.,de Groot-Hedlin C.D.,et al. Investigating Spectral Distortion of Local Volcano Infrasound by Nonlinear Propagation at Sakurajima Volcano, Japan[J],2020,125(3).
APA	Maher S.P.,Matoza R.S.,de Groot-Hedlin C.D.,Gee K.L.,Fee D.,&Yokoo A..(2020).Investigating Spectral Distortion of Local Volcano Infrasound by Nonlinear Propagation at Sakurajima Volcano, Japan.Journal of Geophysical Research: Solid Earth,125(3).
MLA	Maher S.P.,et al."Investigating Spectral Distortion of Local Volcano Infrasound by Nonlinear Propagation at Sakurajima Volcano, Japan".Journal of Geophysical Research: Solid Earth 125.3(2020).