A seismic station at Bamboo Range in St Vincent recorded the signal from a lahar or mudflow around 4am today.
According to the UWI Seismic Research Centre, this lasted for about 30 minutes and may have flown along a valley on the south- eastern side of the La Soufrière volcano.
The SRC reminds that the Volcano Alert Level remains Red, with seismic activity continuing the pattern established after the explosive activity on April 18th.
It adds that the pattern of seismic activity over the last few days is typical of the growth and destruction of lava domes.
Persons are warned that explosions with accompanying ash fall, of similar or larger magnitude, can occur with little or no warning and so, persons are advised to stay out of the Red Zone.