Geophysical granular flows exert basal forces that generate seismic signals, which can be used to better monitor and model these severe natural hazards. A number of empirical relations and existing models link these signals' high‐frequency components to a variety of flow properties, many of which are inaccessible by other analyses. However, the range of validity of the empirical relations remains unclear and the models lack validation, owing to the difficulty of adequately controlling and instrumenting field‐scale flows. Here, we present laboratory experiments investigating the normal forces exerted on a basal plate by dense and partially dense flows of spherical glass particles. We measured the power spectra of these forces and inferred predictions for these power spectra from the models for debris flows' seismic signals proposed by Kean et al. (2015, https://doi.org/10.1002/2015GL064811), Lai et al. (2018, https://doi.org/10.1029/2018GL077683), and Farin, Tsai, et al. (2019, https://doi.org/10.1002/esp.4677), using Hertz theory to extend Farin, Tsai, et al. (2019)'s models to higher frequencies. Comparison of our observations to these predictions, and to predictions derived from Bachelet (2018) and Bachelet et al. (2021)'s model for granular flows' seismic signals, shows those of Farin, Tsai, et al. (2019)'s “thin‐flow” model to be the most accurate, so we examine explanations for this accuracy and discuss its implications for geophysical flows' seismic signals. We also consider the normalization, by the mean force exerted by each flow, of the force's mean squared fluctuations, showing that this ratio varies by 4 orders of magnitude over our experiments, but is determined by the bulk inertial number of the flow.

中文翻译：

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实验室地震：实验对地球物理颗粒流产生的高频地震信号的见解

地球物理颗粒流施加产生地震信号的基力，可用于更好地监视和建模这些严重的自然灾害。大量的经验关系和现有模型将这些信号的高频成分与各种流动特性联系起来，其中许多分析无法通过其他分析获得。但是，由于难以充分控制和测量现场规模的流量，经验关系的有效性范围仍然不清楚，模型也缺乏验证。在这里，我们目前的实验室实验研究了球形玻璃颗粒的致密和部分致密流施加在基板上的法向力。我们测量了这些力的功率谱，并从泥石流模型推论了这些功率谱的预测。Kean等人提出的地震信号。（2015，https://doi.org/10.1002/2015GL064811），Lai等。（2018，https://doi.org/10.1029/2018GL077683），以及Farin，Tsai等人。（2019，https://doi.org/10.1002/esp.4677），使用赫兹理论扩展了Farin，Tsai等。（2019）的模型使用更高的频率。我们的观察与这些预测以及从Bachelet（2018）和Bachelet等人得出的预测的比较。（2021年）的粒状流地震信号模型，显示了Farin，Tsai等人的数据。（2019）的“薄流”模型是最准确的，因此我们研究了这种精确性的解释，并讨论了其对地球物理流地震信号的影响。我们还考虑了通过每次流动施加的平均力对力的均方差进行归一化，