Morne Watt was the source of a major eruption about 1,300 years ago that produced pyroclastic flows. A VEI-2 phreatic eruption occurred at the Valley of Desolation thermal area in 1880, which deposited ash away from the mountain. This was followed by a smaller VEI-1 phreatic eruption in July 1997. The 1880 and 1997 explosions are the only historically confirmed Dominican eruptions.