Report on Soufriere St. Vincent (Saint Vincent and the Grenadines) — 30 December-5 January 2021
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 30 December-5 January 2021
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2020. Report on Soufriere St. Vincent (Saint Vincent and the Grenadines). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 30 December-5 January 2021. Smithsonian Institution and US Geological Survey.
Soufriere St. Vincent
Saint Vincent and the Grenadines
13.33°N, 61.18°W; summit elev. 1220 m
All times are local (unless otherwise noted)
The Seismic Research Centre at the University of the West Indies (UWI-SRC) and National Emergency Management Organisation (NEMO) of St. Vincent and the Grenadines reported that during an overflight at 1600 on 31 December scientists confirmed that the new lava dome on the WSW edge of Soufrière St. Vincent’s 1979 lava dome continued to grow. Steam from the dome was visible from Belmont Observatory through 4 January. The Alert Level remained at Orange (the second highest level on a four-color scale).
Geologic Background. Soufrière St. Vincent is the northernmost and youngest volcano on St. Vincent Island. The NE rim of the 1.6-km wide summit crater is cut by a crater formed in 1812. The crater itself lies on the SW margin of a larger 2.2-km-wide caldera, which is breached widely to the SW as a result of slope failure. Frequent explosive eruptions after about 4,300 years ago produced pyroclastic deposits of the Yellow Tephra Formation, which cover much of the island. The first historical eruption took place in 1718; it and the 1812 eruption produced major explosions. Much of the northern end of the island was devastated by a major eruption in 1902 that coincided with the catastrophic Mont Pelée eruption on Martinique. A lava dome was emplaced in the summit crater in 1971 during a strictly effusive eruption, forming an island within a lake that filled the crater. A series of explosive eruptions in 1979 destroyed the 1971 dome and ejected the lake; a new dome was then built.