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.
The Morne Watt volcano was responsible for a major volcanic event approximately 1,300 years ago that generated pyroclastic flows. In 1880, a VEI-2 phreatic eruption occurred at the Valley of Desolation thermal area, resulting in ash deposition away from the mountain.