Are all the volcanoes in the Caribbean connected so that an erupting volcano on one island will trigger the others nearby?
No, volcanoes in the Caribbean are not connected. Volcanoes on individual islands are formed by the same process, i.e. subduction at the plate boundary, but they do not share the same magma chamber, and are not linked by long underground magma conduits. A volcanic eruption on one island, therefore, cannot trigger an eruption on another island.
What is a geothermal field?
Geothermal fields or systems are areas of hot springs and steam vents, which form when rainwater seeps into the ground. The water is then heated by hot rock that has itself been heated by underlying magma (molten rock). They do not necessarily represent the vent of a volcano.
Are geothermal features such as steam vents as seen at Sulphur Springs in Saint Lucia and Dominica, actually volcanoes?
Hot springs and fumaroles are not volcanoes. They represent small cracks where hot water and steam escape at the surface. They often occur in volcanic areas, where they can be found in the vent, on the slopes, and in the surrounding countryside, miles away from the volcano! For example, the Sulphur Springs in Saint Lucia is part of the much larger Soufriere Volcanic Centre. It is not the volcano.
Does the steaming at geothermal fields act as a safety valve for the volcano?
No, it does not. The Sulphur Springs area in Saint Lucia, for example, includes over 20 hot springs and steam vents. Contrary to popular belief, these do not act as a “safety valve” to reduce the likelihood of an eruption. The steaming in this area is generated from heated rainwater, which comes from above the Earth. It does not indicate that the volcano is “letting off steam” or reducing pressure.
Is Kick-‘em-Jenny the only submarine volcano in the Caribbean?
Kick ‘em Jenny is the only known ‘live’ (likely to erupt again) submarine volcano in the Caribbean.
If Kick-‘em-Jenny erupts will a tsunami (giant sea wave) be generated?
Currently, the volcano is most dangerous for ships and boats since the gases released by Kick ‘em Jenny can lower the density of the water causing them to sink even if it is not erupting. For this reason there is a 2 km exclusion zone around the summit of the Kick ‘em Jenny. Although likely to be minor, tsunamis triggered by underwater eruptions are a potential hazard for neighbouring islands.
What are mud volcanoes? Are they real volcanoes?
Mud volcanoes are vents/fractures through which natural gas such as methane exit, entraining a slurry of mud and sand with it, which they will spew at the surface. Mud volcanoes are not real volcanoes and are not as hazardous as real volcanoes since they can only emit warm mud and only very locally (a few hundred meters around them). Mud volcanoes are generally encountered in areas where natural gas is present. “Real” volcanoes are different. They erupt when magma (i.e., molten rocks) reach the surface and become lava.
Can earthquakes trigger volcanic eruptions?
Earthquakes are not necessarily linked to volcanic activity. Some earthquakes are due to tectonic activity (plates shifting), hence not related to volcanoes, while some others are due to magma trying to find its way up a volcano (volcanic earthquakes). Volcanic earthquake are generally indicative of an increase of volcanic activity but don’ necessarily lead to an eruption. Tectonic earthquakes can “shake” a volcano and can potentially help triggering an eruption. However, they can also potentially stop an eruption. No direct links between tectonic earthquake activity and eruptions in the Eastern Caribbean have been found so far.
Can geothermal energy exploration trigger an eruption?
It is rather unlikely that geothermal exploration can trigger an eruption. However, geothermal energy extraction can modify the surroundings of the exploration sites (e.g., ground subsidence). While these changes will tend to be relatively shallow (compared with the deep roots of a volcano), exploration must be carefully monitored when located close to an active volcano.
Why is it that our volcanoes do not produce ‘rivers of lava’ like the volcanoes in Hawaii?
The type of lava flow depends on the chemical composition of the lava. Lava with low silica content are less viscous (i.e., more “fluid”) and can flow freely downslope as in Hawai’i. Lava with higher silica content are more viscous (i.e., “stiffer”) and cannot flow as freely. They will tend to accumulate close to the vent (e.g., crater) and form lava dome. Our volcanoes in the region tend to produce viscous lava flows (e.g., dome at Soufriere Hills Volcano in Montserrat). But some have produced lava which are fluid enough to produce long distance traveling lava flows, as in St Vincent.