It is difficult to say how long this eruption will last. The length of the eruption is dependent on the amount of energy in the volcanic system. The eruption will end when there is no longer enough energy to bring material to the surface. Based on previous eruptions, the explosive may last several days to weeks.
Explosive eruptions are driven by volcanic gases contained in magma. During the effusive phase this gas was released slowly from the magma as it came to the surface. Eventually the pressure created by more rapidly degassing magma was too much to be contained by the material above the vent. The result is an explosive volcanic eruption. Compare it to ‘popping’ a bottle of champagne!
This eruption appears to be larger than the 1979 eruption in terms of material put into the into the atmosphere. Its explosivity is more comparable to the 1902 eruption of the La Soufriere Volcano.
In most persons volcanic ash will only irritate the eyes and respiratory system. Persons with pre-existing conditions like asthma will be at increased risk to be negatively affected.
Yes, pyroclastic density currents (PDCs) or pyroclastic flows have been observed on the north-western flanks of the volcano. They are usually caused by the collapse of the eruption column, a dome collapse or a lateral blast.
Yes. There has been significant ashfall across mainland St. Vincent. With rain, ash deposits will be swept into rivers and streams forming lahars or mudflows. These flows usually have a high temperature and can carry large amounts of volcanic debris. These can happen months after the eruption has ended.
As the fine particles in the ash column rapidly collide there is a buildup of static electricity. We see the rapid discharge of this electricity as lightning.
Eastern Caribbean volcanoes produce what scientists call Andesitic lavas that are very sticky. They form domes and when they erupt explosively produce lots of ash, debris avalanches and projectiles. Volcanoes like those in Hawaii produce Basaltic lavas that are very runny. These volcanoes often generate lava flows with fewer projectiles.
Yes. Wind will carry ash further away from the volcano with time. Surface or sea level winds will carry ash west and south to the Grenadines and Grenada. In the upper atmosphere winds will take ash north and east. Islands like Martinique and Dominica may receive some ash, but the majority will go out into the Atlantic Ocean or the Caribbean Sea.
Although very unlikely at this time, small tsunamis can be generated if large amounts of material enter the sea. This large-scale movement of material can be caused by a flank collapse or lateral explosion.