Trident volcano (Alaska Peninsula): seismic swarm
Thu, 15 Sep 2022, 10:2210:22 AM | BY: MARTIN
The Alaska Volcano Observatory (AVO) registered a swarm of earthquakes beneath the volcano that started on 24 August and is still continuing.
Trident volcano (image: Smithsonian/Global Volcanism Program)
Quakes were located at deep levels firstly, at about 25 km depth, but have become progressively shallower up to approx. 7-to-5 and even 0 km depth since 28 August until now.
Earthquake magnitudes have ranged between M 0.7 and M 1.9.
At a swarm peak episode, dozen of quakes have been occurring daily beneath the edifice, but over the past week, its frequency has decreased to a couple per day.
The elevated seismic activity may indicate that increased fluid movements of gas, water and possibly magma shift under the surface.
A continuing shallow-level seismicity is expected including other signs of unrest, such as gas, water vapor emissions, elevated surface temperatures or ground deformation.
Source: Alaska Volcano Observatory volcano activity update 15 September 2022