La Soufrière Volcano Update

La Soufrière Volcano Update

April 16, 2021855Views

NOTE: This advisory was prepared at 6:00AM, and therefore does not include the explosion which occurred at 6:15AM.

La Soufriere St. Vincent SCIENTIFIC UPDATE – 16/04/21 6:00AM

1. Seismic activity at La Soufrière, continued as before with a near-constant swarm of long-period and hybrid earthquakes.

2. There was one band of low-level tremor at 9pm on 15 April which lasted about 40 minutes and may have been associated with a small increase in venting.

3. The first successful measurements of sulphur dioxide (SO2) flux at La Soufriere were undertaken along the west coast and yielded an average SO2 flux of 809 tons per day.

4. SO2 is a volcanic gas and flux is the measurement of mass of SO2 in the plume (a stream of gas vented by the volcano).

5. The presence of SO2 tells us that fresh magma from a deeper source is being degassed indicating that the eruption is continuing.

6. The volcano continues to erupt although explosive activity appears to have ended at this time.

7. Its current pattern of seismic activity may indicate growth of a lava dome, but this has not yet been confirmed.

8. Explosions with accompanying ashfall, of similar or larger size, could restart in the future impacting St. Vincent and neighbouring islands.

9. The volcano is at alert level Red

10. Visit the GNS Science website for Global Ash Impact posters. The latest research-informed material for concise best practice information for critical infrastructure managers to effectively prepare for, respond to, and recover from ash-producing volcanic eruptions.

11. Visit the International Volcanic Health Hazard Network for volcanic ash information and resources: