April 23, 2021

Three stations down but seismic monitoring still strong

Five of eight seismic stations monitoring the volcano were still up and running as at just over a week after La Soufrière began erupting explosively.  

 Of the three-man team currently on the ground monitoring the volcano as it continues to erupt, experienced volcano-seismologist Roderick Stewart is in charge of reading the different earthquakes that signal the movement of magma.

 The stations “pick up ground vibrations that are generated by earthquakes, they also are generated by human … waves crashing and that sort of thing but all the data from these stations comes back here and gets processed for the earthquake activity,” Stewart explained to SEARCHLIGHT from the Belmont Observatory in North Leeward on Saturday, April 17.  

 “…the earthquake activity underneath the volcano is one of the key monitoring techniques, especially in real time, to know what’s going on,” he said.  

 One of the challenges scientists face as they monitor volcanos is trying to do science with incomplete data such as the stations disappearing.  

 Of their network of stations, one was at the summit, and they believe this to have been destroyed in the explosions.

 As it relates to the stations in Fancy and Owia, there was no electricity or communications to those areas.  

 “We’ve got a station, Georgetown and that seems to be going on and off because of the power issues in Georgetown, and so we’ve lost three of our stations but we’ve got five, which means we can still do the monitoring, maybe not as perfect as before,” Stewart continued.  

 The scientist revealed that their station at Wallibou has been surprising them because a lot of ash has been coming down in that direction.  

 “The station’s actually solar powered and the solar panels get covered in ash, and we lose power, but SDD, which is Wallibou has actually worked throughout the eruption,” the seismologist noted.

 Pyroclastics flows coming down in the valleys have been avoiding them.