Pyroclastic flow is one of the devastating after effects of Volcanic eruption. It is the tephra, which comes out of the volcano after the eruption has occurred and is of a very high temperature. Tephra is the mixture of gas ash and rock all in a liquidized form at a temperature as high as 100 to 800 degrees. This is the most dangerous part of any Volcanic eruption as it destroys all types of natural vegetations and human habitation, which comes in its way. The Pyroclastic flow travels down the hill slope and the speed of the flow depends on its size and the steepness of the slope.

Causes of Pyroclastic flow

• At times, when the erupted gas is unable to heat the surrounding air enough to hold it then it falls back on the slope of the volcanic mountain, along with the molten ash and rocks. In such a situation, the Pyroclastic flow will occur due to the absence of convection currents above the mouth of the volcano.

• The sudden fall of the dome of the lava may also result in Pyroclastic flow

• When a part of the volcano erupts and causes a directional blast then it results in Pyroclastic flow

• Pyroclastic flow may also result from frothing at the mouth of the volcano when the eruption is taking place, which produces igneous rocks called ignimbrite.

Effects of Pyroclastic flow

The hot gases, which are part of the Pyroclastic flow may result in acid rain in the surrounding regions. Apart from that the molten ash and rocks may also cause extreme damage and loss of life and property. The Pyroclastic flow has the capacity to travel for more than hundreds of kilometers, and thus, there are all the chances that it may be dangerous for the human habitation.

Volcanic eruption is one of the most devastating Weather-related disasters due to the presence of the Pyroclastic flow after the eruption.