In the Caribbean, there are a number of active and very dangerous volcanoes. These volcanoes
are located on islands in the Lesser Antilles. One of these islands, Guadeloupe, contains a
volcano which once again appears to be waking up from dormancy. The volcano I am referring to is
called Soufrière Guadeloupe, which is currently at a raised alert status. This video will discuss
the recent eruptions from this volcano, and mention what hazards it might pose in the future.
The island of Guadeloupe is located in the northern half of the Lesser Antilles,
between Montserrat and Dominica. The active volcano I will be discussing is located in
the southern third of the island, and is 8 kilometers east northeast of the capital city.
Like many volcanoes in the Caribbean, the Soufriere Guadeloupe volcano is quite young.
It began forming on the island only 200,000 years ago. The early eruptions from this
volcano produced very quite explosive, and deposited alternating layers of andesite,
dacite, and ash. The presence of dacite rock is important, as it indicates that this volcano is
far more explosive than a typical stratovolcano. Examples of other stratovolcanoes which commonly
erupt dacite include Mount Saint Helens, Santorini, and Krakatoa.
All of these volcanoes have produced massive eruptions which formed calderas, and Soufriere
Guadeloupe is no exception. After more than 100,000 years of eruptions, this volcano stood at
1700 meters tall, which is much higher than its modern height. Then, 42,000 years ago, the largest
eruption known as this volcano took place. At first, a tall plume of ash shot into the sky,
reaching 35 kilometers into the atmosphere. As the eruption continued, pyroclastic flows
and bombs of lava traveled down the volcano's slopes. During the climax of this eruption,
the volcano collapsed about a kilometer into the ground, and formed a 3 kilometer wide caldera.
In the aftermath of this eruption, a new volcanic cone began growing at the center of the caldera.
This cone was built via explosive eruptions which created a combination of lava domes, ash, and more
fluid lava flows. Over the next 30,000 years, three distinct periods of activity occurred,
each of which resulted in the further building of the main vent. By 12,000 years ago, this volcano
was once again close to its pre caldera height. However, the western side of Soufrière Guadeloupe
was beginning to show signs of structural instability. During the next eruption,
a large section buldged outwards more than 50 meters in this direction, which caused pressure
to build. Finally, the pressure was released via a violent eruption. The eruption caused the
majority of the volcano to slide westwards into the Caribbean Sea in an eruption similar to what
was witnessed from Mount Saint Helens in 1980. However, the structural weakness in the volcano
did not vanish due to the eruption, but was rather exacerbated. Over the next 3,000 years,
a series of lava domes built a new peak known as Amic. Eventually, this complex of domes got so
massive, that it once again collapsed to the west in an eruption 8500 years ago. Over the
next 5400 years, a similar cycle of eruptions built a new peak, got too large, and once again
collapsed in a third catastrophic eruption. Since then, several smaller sector collapses
have taken place on the west side of the mountain. Two of these occurred in 1100 BC and then again
in 250 AD. The most recent collapse in 1550 is of particular note as it also represents the
most recent eruption of lava from this volcano. Since then, 9 explosive eruptions with no lava,
termed phreatic eruptions, have taken place from several vents on Guadeloupe's summit. The most
recent of these occurred from 1976 to 1977, during which more than 70,000 people were evacuated.
This volcano poses a danger which I could only truly describe as similar to Pelee on Martinique.
Tens of thousands of people live in the highest risk area to the west of the summit which
periodically gets destroyed by eruptions every 900 years. Luckily, if this volcano was to produce a
major eruption and summit collapse, there would be several warning signs ahead of time. These
warning signs would include unusually intense fumarole activity followed by phreatic eruptions,
a bulge in the western slope of the mountain, or even more obvious, lava erupting onto the surface.
The last of these warning signs is quite important, as the at risk section of the volcano
needs more mass before it can collapse. With this being said, the vast majority of eruptions from
this volcano are far less destructive and occur as phreatic explosions. Overall, the odds of an
eruption in any given year are about 1 in 44. I hope that you enjoyed this video.
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