The volcanic eruptions
What is a volcanic eruption ?
The crust of the earth is constantly changing. If you can't see with the naked eye, the rocks move across the globe. This activity materializes especially near large faults that run through it. These vulnerabilities allow the magma (a mixture of molten rock, which has become liquid because of the heat and gas) back. During an eruption, the pressures allows the magma to escape to the surface by a crater or fissure, which are openings, exit points. The magma then takes the name of washing, and cooling and solidifying, it creates a cone called a volcano.
Types of volcanic eruptions
The eruptions effusive
Causes of rashes regular washing fluid at high temperature (about 1200° C), flowing slowly on the slopes of the volcano.
The explosive eruptions
The magma is viscous, a little liquid-rich and gas accumulates in-depth, under the dome, which acts as a " stopper ". When the pressure becomes too strong, the magma is expelled violently, creating large plumes of gas and ash clouds that can take the form of glowing clouds.
The volcanoes in the caribbean are volcanoes explosive.
In addition to lava flows and discharges of gas, volcanoes can generate other hazardous weather, such as lahars. A lahar is a mudflow of volcanic : it is formed when water from heavy rains mixed with ash and volcanic debris. The lahars can hurtle down quickly the slopes and cause significant damage in populated areas. https://pirac.croix-rouge.fr/project/que-faire-en-cas-coulee-de-boue-lahar-volcan/
The eruptions marked the history of the Caribbean, check out these past events by clicking here.
The volcanic eruptions in the Caribbean
The Caribbean is a region marked by strong volcanic activity, this area is called the arc of the lesser Antilles. The volcanic activity of the earth is shaped by plate tectonics, and the rise of magma underground. In fact, the earth is divided into a dozen plates that drift in relation to each other. The displacement of the different plates leads to a variety of mechanisms at the level of their borders, and in particular :
Convergence Zone
A plaque can dive under another, this is called subduction zones
Area of divergence
The warm material rises to the surface of the earth and pushes the plates
The west indies is a chain of volcanic islands that extends into the Caribbean sea and having been created by the succession of volcanic eruptions from about 40 million years ago.
Diagram of the formation of the west indies ( ©Risque972)
To the east of the Caribbean sea, the plate tectonics of the North American Atlantic (less dense) converges up to slide slowly under the plate and the Caribbean (more dense), it is called subduction. This meeting of the plates, which takes millions of years and at a very slow speed on a human scale (a few centimeters per year), are significant geologically resulting in a volcanic area is very active. Sinking in the earth's mantle, the oceanic plate undergoes very
high pressures and temperatures, which causes the creation of magma. This magma then rises to the surface and feeds the volcanoes.
The succession of volcanic eruption has shaped the development of the west indies for about 40 million years ago. Today the volcanic activity still today continues to shape the landscape Caribbean.
The volcanoes in the caribbean are volcanoes explosive, even if some have been able to exhibit phases effusive.
Source : Booklet teacher, cycle 3 – Project "Pare pa Pare" – French Red Cross – 2022
Map of active volcanoes of the lesser Antilles
For more information :
Redirect links
Risk 972 – Monitoring and Safety Tips Explanation on the phenomenon, the hazards, how to protect themselves and the eruptions in the lesser Antilles (En)
Volcanoes | The UWI Seismic Research Centre University of the West indies explanation on the volcanoes (Eng)
Volcanic eruption | Geohazards Guide and French device on volcanic eruptions – Geohazards(en)
Menu
Home
Natural hazards
Protect
Risks island
The toolbox
About
Quick access
Resources
Glossary
Contact
FAQ
Cookie policy (EU)
Pirac
OECS
CDEMA