近日，新西兰坎特伯雷大学Leighton M. Watson及其小组利用地震信号追踪埃特纳火山的火山碎屑密度流。该项研究成果发表在2023年2月27日出版的《JGR地球》上。

本文使用意大利埃特纳火山永久监测网络记录的地震数据，以秒级时间分辨率追踪2014年2月11日的火山碎屑密度流，并计算出最大速度为76米/秒(274公里/小时)。研究人员识别了多个脉冲，并表明晚期震源位置与所映射的粗粒火山碎屑密度流沉积相对应。通过地震数据对火山碎屑密度流运动进行高时间和空间分辨率的测量，可以为火山碎屑密度流动力学的数值模拟提供信息，并通过提高对火山碎屑密度流流动路径的理解来帮助进行危险评估。这项工作阐明了如何以地震信号为主题来实时跟踪地表质量运动。

据介绍，火山碎屑密度流(PDCs)是火山岩石和气体的危险流动，是最致命的近火山灾害。人们对更好地理解火山碎屑密度流的动力学有很大的兴趣，然而，由于其极端的危险性，不可预测的发生率，以及复杂的内部动力学被视觉上不透明的火山灰云所掩盖，因此研究它们具有挑战性。火山碎屑密度流在地球表面施加力并产生地震波。

附：英文原文

Title: Tracking a pyroclastic density current with seismic signals at Mt. Etna (Italy)

Author: Leighton M. Watson, Andrea Cannata, Daniele Andronico

Issue&Volume: 2023-02-27

Abstract: Pyroclastic density currents (PDCs) are dangerous flows of volcanic rock and gas that are the most deadly proximal volcano hazard. There is significant interest in better understanding PDC dynamics, however, they are challenging to study due to their extreme hazard, unpredictable occurrence, and because complex internal dynamics are obscured by visually-opaque clouds of ash. PDCs exert forces on Earth’s surface and generate seismic waves. Here, we use seismic data recorded by the permanent monitoring network at Mt. Etna (Italy) to track the 11 February 2014 PDC at second-scale temporal resolution and calculate a maximum velocity of 76 m/s (274 km/hr). We identify multiple pulses and show that the late-stage source locations correspond with the mapped coarse-grained PDC deposits. High temporal and spatial resolution measurements of PDC movement from seismic data can be used to inform numerical modelling of PDC dynamics and aid in hazard assessment by improving our understanding of PDC flow paths. This work illustrates how seismic signals can be used to track surficial mass movements in real-time.

DOI: 10.1029/2022JB026114

Source: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022JB026114