Volcanic debris flow stops in St Vincent…for now Friday 30 April 2021 Lahars observed in the Wallibou river (Red Zone, Leeward side of the island) on Thursday morning. Photo by Prof Richard Robertson, UWI-SRC - AS the lahars (flows of volcanic material) come to a halt in St Vincent and the Grenadines, at least for now, the government is assessing the damage they caused, which included landslides and uprooting trees, among other things. On Thursday, the country experienced heavy rain. With the La Soufriere volcano still active, it was not a good combination. Heavy rain results in the formation of lahars at a volcano. The UWI Seismic Research Centre defines a lahar as “fast-moving, dense mixture of rocks, ash and vegetation and water…It has the consistency of wet concrete and can cause severe damage to rivers and valleys around the volcano.