Accumulating Evidence: Animation

In December 2020, a new lava dome was spotted growing in the crater of La Soufrière St Vincent. It continued to grow until early April 2021 when an explosive eruption ocurred. 

Almost all of the new dome, and most of the dome left behind after the 1979 eruption was destroyed, blasted apart and mixed with ash and other rocks from the crater floor.

During the eruption, scientists recorded the trembling of the earth using seismometers and traced the height and direction of the ash column via satellite.

Once explosions stopped on the 22nd April volcanolgists from the University of the West Indies Seismic Research Centre, The University of Plymouth and the University of East Anglia made sure to record thorough descriptions of the layers of material deposited during the eruption. This was a race against time as heavy rains meant a lot of the material was rapidly removed from the land surface. 

In the animation below (narrated by Prof Richie Robertson - UWISRC), we have combined the various observations made during the eruption to reconstruct the sequence of explosions and show how they connect to the ash and rocks left behind.

In many cases, the rocks left behind after an eruption are the only evidence we have of what happened.

Volcanologists draw links between rocks produced during observed and unobserved eruptions to understand volcanic hazard at volcanoes that erupt less frequently!