The Volcano Acoustic Source: Decoupling Crater Modulation From Infrasound Signal

火山声源：从次声信号中解耦火山口调制

• 批准号: 1830976
• 负责人: Jeffrey Johnson
• 金额: $ 33.48万
• 依托单位: Boise State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-03-15 至 2023-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1830976&HistoricalAwards=false
• 关键词: Volcano; Acoustic; Source; Decoupling; Crater

Volcanoes radiate intense sounds concentrated in the infrasound band, which is below the frequency threshold of human hearing. Such sounds are often recorded many kilometers from a volcano and are used by scientists and observatories to continuously observe eruptions; commonly infrasound is used to detect explosions and to measure eruption intensity and character. This study's objective is to improve the understanding of how infrasound relates to eruptive processes occurring within a volcanic crater. To implement infrasound as an effective tool it is necessary to understand how the recorded sound signals are modulated by crater shape. This work aims to measure, model, and quantify the influence of the crater's acoustic response, which influences the radiated sound much like the horn of a musical instrument. Measurements will include field work where the sound field is recorded both within and outside the craters of active volcanoes. Anticipated results will lead to improved modeling of eruptive processes and to better recognition of changes in volcanic unrest. This study will bring together a diverse international team spanning numerical, analytical, and field expertise from not just Idaho, but Hawaii, Chile, Italy, and the Democratic Republic of the Congo. The work will also fund graduate and undergraduate students, and contribute to exciting public outreach opportunities which include chronicling the efforts through a component of professional videographies. The crater acoustic response is a transfer function, which relates source processes occurring at the bottom of a volcanic crater to the infrasound that is radiated to distant receivers. An understanding of the crater acoustic response is critical to improving utility of volcano infrasound recordings for both general monitoring and for improving physics-based eruption models. In cases where craters are deep and narrow and/or assymetric, the crater acoustic response can be particularly extreme and can significantly distort a source-time function. Deconvolution of the crater's acoustic response is thus critical to recovering accurate source-time functions. This study's integrated numerical modeling and field work, which incorporates large-N infrasound sampling, will permit robust quantification of the crater's sound modulation effects. Anticipated results will permit researchers to better infer source parameters and to invert for crater geometry, which may vary dynamically over time at active volcanoes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

火山散发着集中在伸向带中的强烈声音，该声音低于人类听力的频率阈值。这种声音通常从火山中记录下来数公里，并被科学家和观察者使用来连续观察喷发。通常使用伸出来检测爆炸并测量喷发强度和特征。这项研究的目的是提高对伸射线与火山口内发生的喷发过程的关系的理解。要实现侵权用作作为有效工具，有必要了解如何通过火山口形状调节记录的声音信号。 这项工作旨在测量，建模和量化火山口声反应的影响，这听起来像是乐器的角。测量将包括现场工作，其中有活跃火山的陨石坑内外记录声场。预期的结果将导致改善喷发过程的建模，并更好地识别火山动乱的变化。这项研究将汇集一支多样化的国际团队，不仅来自爱达荷州，还包括夏威夷，智利，意大利和刚果民主共和国。这项工作还将为研究生和本科生提供资金，并为令人兴奋的公共宣传机会做出贡献，其中包括通过专业摄影的组成部分记录努力。火山口声响应是一种传递函数，它将发生在火山坑底部的源过程与辐射到远处接收器的源过程相关。对火山口声反应的理解对于改善一般监测和改善基于物理的喷发模型的火山插射记录的效用至关重要。在陨石坑深而狭窄和/或囊泡的情况下，火山口声反应可能特别极端，并且可能会大大扭曲源时间函数。因此，火山口声响应的反卷积对于恢复准确的源时间功能至关重要。这项研究的集成数值建模和现场工作结合了大N非传动采样，将允许对火山口声调制效应进行强有力的量化。预期的结果将使研究人员能够更好地推断出源参数并颠倒火山口几何形状，而火山口几何形状可能会随着活跃的火山而动态地变化。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点评估来获得支持的，并具有更广泛的影响标准。

项目成果

PORTABLE REAL-TIME VOLCANO INFRASOUND AUDITORY DISPLAY DEVICES

便携式实时火山次声听觉显示设备

• 发表时间: 2021
• 期刊: Proceedings of the International Conference on Auditory Display
• 作者: Apel, T.;Johnson, J.B.
• 通讯作者: Johnson, J.B.

Volcano infrasound: progress and future directions

• DOI: 10.1007/s00445-022-01544-w
• 发表时间: 2022-04
• 期刊: Bulletin of Volcanology
• 影响因子: 3.5
• 作者: L. M. Watson;A. Iezzi;L. Toney;S. Maher;D. Fee;Kathleen F. McKee;H. Ortiz;R. Matoza;J. Gestrich;J. Bishop;Alex J. C. Witsil;Jacob F. Anderson;Jeffrey B. Johnson

Analyzing continuous infrasound from Stromboli volcano, Italy using unsupervised machine learning

• DOI: 10.1016/j.cageo.2020.104494
• 发表时间: 2020-04
• 期刊: Comput. Geosci.
• 作者: Alex J. C. Witsil;Jeffrey B. Johnson

Unoccupied Aircraft Systems (UASs) Reveal the Morphological Changes at Stromboli Volcano (Italy) before, between, and after the 3 July and 28 August 2019 Paroxysmal Eruptions

• DOI: 10.3390/rs13152870
• 发表时间: 2021-08-01
• 期刊: REMOTE SENSING
• 影响因子: 5
• 作者: Civico, Riccardo;Ricci, Tullio;Taddeucci, Jacopo
• 通讯作者: Taddeucci, Jacopo

Changes in Crater Geometry Revealed by Inversion of Harmonic Infrasound Observations: 24 December 2018 Eruption of Mount Etna, Italy

• DOI: 10.1029/2020gl088077
• 发表时间: 2020-10-16
• 期刊: GEOPHYSICAL RESEARCH LETTERS
• 影响因子: 5.2
• 作者: Watson, Leighton M.;Johnson, Jeffrey B.;Cannata, Andrea
• 通讯作者: Cannata, Andrea