Mount Pelée, a volcano on the Caribbean island of Martinique, has recently exhibited increased seismic activity, including a notable surge in earthquakes and ground deformation, leading scientists to raise the alert level and caution that a future eruption cannot be ruled out.
This activity has reignited concerns given the volcano's history. On May 7, 1902, Mount Pelée experienced one of the deadliest eruptions of the 20th century, unleashing a pyroclastic flow of hot gas, ash, and rocks that destroyed the nearby city of Saint-Pierre, killing approximately 30,000 people. This event made it the third deadliest volcanic eruption of that era.
Experts at the Martinique Volcanological and Seismological Observatory detected 124 earthquakes between July 24 and July 31, a nearly threefold increase compared to the week prior. Over the entire month of July, 331 volcanic earthquakes were recorded, averaging about 85 per week. This trend is reminiscent of activity observed in 2019, when the volcano's earthquake count rose significantly above the baseline of 19 per month and remained elevated for several months.
Volcanic earthquakes are typically caused by the fracturing of rock masses beneath a volcano due to stressors such as rising magma or hydrothermal fluids, according to the Pacific Northwest Seismic Institute. While the recent seismic events, none exceeding a magnitude of 1 and not felt by the local population, do not necessarily indicate an imminent eruption, scientists are monitoring the situation closely.
In addition to seismic activity, scientists have recorded several inches of ground movement per month at Mount Pelée's summit since May. These subterranean shifts are attributed to deformation occurring approximately 0.6 miles below the surface, causing the summit to inflate. Although the rate of this ground movement has slightly decreased in the past four weeks, suggesting a potential easing of pressure, experts emphasize that vigilance is still required.
The Martinique Observatory has raised the alert level to "YELLOW," indicating a need for heightened awareness. While the probability of an eruption in the immediate short term remains low, the observatory stated that "considering the observations accumulated over the past months and years, an evolution of the situation in the medium term (weeks to months) cannot be excluded."
Should Mount Pelée erupt today, a 2021 study suggests that pyroclastic flows could endanger the island's 400,000 residents, and ashfall could disrupt electricity and air travel. The volcano has been dormant since 1932, but the recent increase in activity has prompted renewed scientific scrutiny.