We studied a triggered snow avalanche (∼60 s in duration and with ∼1,100 m run‐out) using a network of infrasound arrays and time‐synced video, with the objective of understanding the relationship between infrasound generation and flow dynamics. Using standard array processing techniques, we compared the infrasound source back azimuths with the avalanche flow path identified by frame‐differenced, geo‐referenced video. Results show that infrasound records begin with direct arrivals followed by echoes from the avalanche‐triggering explosions and these decay within 35 s of the detonations. Subsequent infrasound, which lasts 20–30 s, could then be attributed exclusively to the avalanche. These infrasound detections, and their triangulated source locations, progress downhill over time and the most intense infrasound appears to originate from a steep, mid‐path cliff band, where the avalanche reached speeds in excess of 30 m/s and accelerations of more than 5 m/s². The recorded infrasound was compared to two candidate source models extracted from video: total flow motion and advancing flow motion. Advancing source locations were compared to acoustic intensity time series using a nonnegative least squares inversion to solve for, and to quantify, time‐varying infrasound source intensity. We observed that certain portions of the flow, most notably the early stages and the end stages (when the powder cloud was expanding and settling) were infrasonically quiet.

中文翻译：

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使用次声传感器网络阵列进行的雪崩检测和源约束

我们使用次声阵列和时间同步视频研究了触发的雪崩（持续时间约60 s，跳动约1100 m），目的是了解次声产生与流动动力学之间的关系。使用标准阵列处理技术，我们将次声源背向方位角与由帧差，地理参考视频识别的雪崩流路进行了比较。结果表明，次声记录始于直接到达，然后是雪崩触发的爆炸回波，并在爆炸后35 s内衰减。随后的次声持续20–30 s，可以专门归因于雪崩。这些次声检测及其三角源位置随着时间的推移而逐渐下坡，而最强烈的次声似乎源自陡峭的，²。将记录的次声与从视频中提取的两个候选源模型进行了比较：总流动运动和前进流动运动。使用非负最小二乘反演将前进声源位置与声强时间序列进行比较，以解决并量化随时间变化的次声声源强度。我们观察到流量的某些部分，特别是早期阶段和结束阶段（当粉末云团膨胀和沉降时）在次声上是安静的。