Why do volcanoes erupt

Volcanoes are good examples of natural events that can be both awe inspiring and destructive to behold. Events like the eruption of Vesuvius, which buried the Italian town of Pompeii, serve as a reminder of a volcano’s explosive and sudden power. A volcanic eruption may appear to be a sudden and spontaneous event but in reality it is the culmination of a very long process over a period of time that can span centuries.

The volcano itself is a geologic formation with long narrow openings that lead to deep within the Earth. These openings are formed by the pressure from the Earth’s tectonic plates either colliding or pulling apart. Much like pipes, the openings transport liquid – in this case magma (molten rock) – which is formed when the heat and pressure within the earth melt the rock. It is this heated magma that eventually comes out of the volcano in the form of molten hot lava.

To explain this process in detail, the melted rock (magma) must go through a circulation first forming at the bottom of the volcano before starting its journey up the volcano’s main vent that leads right to the top of the volcano. The lava makes its way slowly up the main vent, getting hotter and hotter all the while as it is allowed to utilize oxygen in the air to amplify its heat.

The magma turns into an extremely hot liquid when it gets around halfway up the main vent. This liquid is called lava. While continuing its slow and irrevocable journey up the main vent the lava becomes hotter and hotter still, all the while collecting ash and rocks on its path. Finally after this slow and continual rising and building of pressure the lava reaches the top of the vent at the volcano’s apex and it is at this point that the volcano erupts. Once the pressure reaches a critical point the molten lava blasts out of the volcano, carrying with it the molten rock, ash and a thick cloud of dust that was collected during its path to the apex.

While the ash and rock rain down on the land below the molten lava flows down the side of the volcano. The lava will flow at different rates from different eruptions and will burn anything in its path at it can reach up to 1250 degrees Celsius, though most lava ejected from volcanoes burns at an average temperature of 750 degrees Celsius.

Volcanoes can be found both on land and under water, and the difference in environments will affect the speed of eruption as well as the likely result. Volcanoes that are situated under water will often take longer to erupt due to the fact that water slows the progress of the magma and lava. Also, the resulting explosion will likely form an island-or a series of islands. The Hawaiian Islands are a particularly good example of this, as is the “Ring of Fire” located in the Pacific that is a result of a series of volcanic eruptions that have formed a number of land masses.