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Strong increase in the unrest of La Soufrière of Guadeloupe Volcano
Tuesday 4 june 2019
A seismic swarm localised below the volcano started on 4 june 2019 at 05h00 local (9h00 TU) and continues. More than 20 earthquakes have been recorded by the OVSG. The swarm began with 2 felt earthquakes M4 and M2,5 that were described in the automatic felt earthquake B3 message sent at 05h40 and 05h50 local. The other earthquakes in the swarm have magnitudes < 1. Epicenter are located below La Soufrière volcano dome between 1 and 2 km below sea level (between 2,6 and 3,6 km below the summit). At 5h45 local (9h45TU), the multigaz station of the South crater (summit of La Soufriere) recorded an increase of the concentrations of carbon dioxide (CO2 up to 2000ppm), sulfur dioxide (SO2 up to 10ppm) and hydrogen sulphide (H2S ) that saturates the sensors (more than 200ppm).
This activity is accompagnied by strong steady roaring jet noise from the volcano and a clearly perceived hydrogen sulfide H2S odour in Saint-Claude town about 2 km away from the volcano.
This activity is also accompanied by an increase of deformations recorded 1 hour before the main felt M4 earthquake on the radar extensometer with almost 2 cm of opening of the 30 August frcture in one hour since the M4 earthquake.
The alert level is now ORANGE (watch)
Further information will be given during the day.
For more information:
> OSVG page on IPGP website
> facebook OVSG
> facebook et twitter de la préfecture