Fireworks: A Potential Artificial Source for Imaging Near-Surface Structures
Fireworks: A Potential Artificial Source for Imaging Near-Surface Structures
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DOI：
10.1785/0220220281
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发表时间：
2023-10
影响因子：
3.3
通讯作者：
Risheng Chu;Qingdong Wang;Zhigang Peng;Minhan Sheng;Qiaoxia Liu;Haopeng Chen
中科院分区：
文献类型：
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作者：
Risheng Chu;Qingdong Wang;Zhigang Peng;Minhan Sheng;Qiaoxia Liu;Haopeng Chen
由空气扰动的入射声波引起的地震波可用于对近地表结构进行成像。在本文中，我们分析了农历除夕（2017 年 1 月 27 日）中国西南部四川省理县西山村陆侧密集阵列记录的地震波形。烟花爆炸总共确定了八个事件群。对于每个由数十个具有高度相似性的单个事件组成的簇，我们手动选取阵列记录的第一个事件的到达时间，并使用网格搜索方法对其进行定位。然后将所有事件的三分量波形从东、北、垂直坐标系旋转到当地LQT坐标（L，垂直于滑坡面且指向下方的正方向；Q，从烟花发射位置沿滑坡面到站点的正方向；T，垂直于L和Q方向形成的平面，选定的T轴正方向使LQT形成左手坐标系），并将这些事件的LQT分量叠加为相对于第一个事件的互相关值 CC ≥ 0.8。还检查了堆叠 LQT 组件的特性。每个站点的粒子运动在~5-50 Hz的频率范围内都是逆行椭圆，这表明烟花爆炸产生了空气耦合瑞利波。瑞利波的谱图也显示出清晰的色散，这可用于对近地表速度结构进行成像。尽管由于地震阵列的限制，我们无法直接提取相速度，但我们的研究表明，烟花可能为近地表结构成像提供低成本且易于使用的地震源。
Seismic waves induced by incident acoustic waves from air disturbances can be used to image near-surface structures. In this article, we analyze seismic waveforms recorded by a dense array on the Xishancun landside in Li County, Sichuan Province, southwest China during the Lunar New Year’s Eve (27 January 2017). A total of eight event clusters have been identified as a result of firework explosions. For each cluster, which comprises dozens of individual events with high similarity, we manually pick arrival times of the first event recorded by the array and locate it with a grid-search method. We then rotate three-component waveforms of all events from the east, north, and vertical coordinate system to the local LQT coordinates (L, positive direction perpendicular to the landslide surface and pointing downwards; Q, positive direction is from the launch location of firework to the station along the landslide surface; T, perpendicular to the plane formed by the L and Q directions, and the selected positive direction of the T axis makes LQT form the left-hand coordinate system), and stack the LQT components for those events with cross-correlation values CC ≥ 0.8 with respect to the first event. Characteristics of the stacked LQT components are also examined. The particle motions at each station are retrograde ellipse in the frequency range of ∼5–50 Hz, suggesting air-coupled Rayleigh waves generated by the firework explosions. Spectrograms of the Rayleigh waves also show clear dispersions, which might be used to image near-surface velocity structures. Although we cannot directly extract the phase velocities due to the limitation of the seismic array, our study shows that the fireworks might provide a low-cost and easy-to-use seismic source for imaging near-surface structures.