We demonstrate the capability of distributed acoustic sensing (DAS) to record volcano-related dynamic strain at Etna (Italy). In summer 2019, we gathered DAS measurements from a 1.5 km long fibre in a shallow trench and seismic records from a conventional dense array comprised of 26 broadband sensors that was deployed in Piano delle Concazze close to the summit area. Etna activity during the acquisition period gives the extraordinary opportunity to record dynamic strain changes (∼ 10⁻⁸ strain) in correspondence with volcanic events. To validate the DAS strain measurements, we explore array-derived methods to estimate strain changes from the seismic signals and to compare with strain DAS signals. A general good agreement is found between array-derived strain and DAS measurements along the fibre optic cable. Short wavelength discrepancies correspond with fault zones, showing the potential of DAS for mapping local perturbations of the strain field and thus site effect due to small-scale heterogeneities in volcanic settings.

中文翻译：

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在埃特纳火山火山（意大利）上用密集地震仪阵列对光纤进行应变测量的比较

我们展示了分布式声学传感（DAS）记录埃特纳火山（意大利）与火山有关的动态应变的能力。在2019年夏季，我们收集了一条1.5公里长的浅沟槽中的光纤的DAS测量数据，并收集了由密集的传统阵列组成的地震记录，该阵列由26个宽带传感器组成，这些传感器部署在靠近峰顶区域的皮亚诺·德尔·康卡泽（Piano delle Concazze）中。在采集期间火山活动给出了非凡机会记录动态应变变化（〜  10 ^-8应变）与火山事件相对应。为了验证DAS应变测量，我们探索了阵列派生的方法来估计地震信号中的应变变化并与DAS信号进行比较。在阵列衍生的应变和沿光缆的DAS测量之间发现了一个总体良好的协议。短波长差异对应于断层带，显示了DAS潜在的绘制应变场局部扰动的地图，以及由于火山环境中的小规模异质性而引起的位点效应。