The La Soufriere volcano on the Caribbean island of Saint Vincent began erupting on April 9, 2021, throwing ash at least 7.6 km above sea level.
The volcano continued to erupt over the next few days with many violent explosions, allowing satellites to take stunning images of the eruptions and monitor the volcanic eruptions and ash clouds that were generated. La Soufriere last erupted in 1979.
Ash covered St. Vincent and winds carried ash to Barbados, about 200 km to the east, scientists from NOAA and NASA said, adding that the region is preparing for possible weeks of ashfall.
The violent eruption on April 12 triggered pyroclastic flows – a high-density mixture of hot blocks of lava, pumice, ash and volcanic gas that travels at very high speeds down the volcanic slopes. The eruptions also caused massive power outages and evacuations of the population.
Volcanic emissions contain gases and volcanic ash and create complex clouds that can affect local, regional and even global weather.
Given the remote location of most volcanoes and the rapid formation and expansion of volcanic clouds, geostationary satellites such as NOAA’s GOES-16 and GOES-17 are the primary tool for monitoring volcanic clouds.
Because they rotate 35,785 km above the Earth’s equator, at the same speed as the Earth, the GOES satellites have a constant view of the same area.
This means they can track volcanic eruptions in near real time, detecting and tracking volcanic ash in a timely and accurate manner, which is critical to maintaining safety and minimizing economic losses.
According to the Washington VAAC, volcanic ash has risen 16 km above sea level in the past couple of days.
“At these altitudes, volcanic ejections can remain in the atmosphere for long periods of time and easily circle the Earth for days, weeks or even months, and their presence affects the earth’s climate, cooling it by blocking energy from the sun,” says NASA scientist Colin Seftor.