Tracking a Pyroclastic Density Current With Seismic Signals at Mt. Etna (Italy).

Autor: Watson, Leighton M., Cannata, Andrea, Andronico, Daniele
Předmět:
Zdroj: Journal of Geophysical Research. Solid Earth; Mar2023, Vol. 128 Issue 3, p1-12, 12p
Abstrakt: 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 modeling 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. Plain Language Summary: Pyroclastic density currents are deadly, very often sudden and unexpected, fast‐moving clouds of hot volcanic gas, ash, and rock. They travel extremely quickly and are very hazardous. As the pyroclastic density current (PDC) flows downslope, it pushes onto Earth's surface producing seismic waves. From these seismic signals, we can track the flow. We study a PDC that occurred at Mt. Etna (Italy) on 11 February 2014. Using the seismic signals, we track the flow and calculate a velocity of 274 km/hr. This work shows how seismic signals can be used to track moving flows, which has applications for understanding complex flow dynamics and real‐time monitoring. Key Points: Pyroclastic density currents (PDCs) are hazardous volcanic flows that generate seismic and acoustic signalsBy considering the attenuation of seismic amplitudes with distance, seismic signals can be used to track PDCsSeismic signals can be used to track PDCs and other surficial mass movements in real‐time [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index