Lava is molten rock discharged from a volcano during an eruption. Volcanic eruptions are caused by the ascent of magma to the surface of the earth. When freshly discharged, lava liquid is extremely hot; temperature ranges from 1300 °Fahrenheit to 2200 ° Fahrenheit.  Lava is quite thick in nature and can flow for long distances, before congealing into igneous rock. Lava is quite destructive, causing damage to property within the vicinity of a volcano.

People are not usually affected by lava due its slow moving nature. However there have been rare instances where human lives have been lost due to fast movement of lava. Sometimes poisonous gases emitted from volcanoes or explosions due to contact of lava with water, have lead to human casualities. Towns such as Kapoho in Hawaii, Cagsawa in the Philippines, and San Sebastiano al Vesuvio in Italy have been completely destroyed by lava flow or volcanic eruptions.

Types of Lava

Lava, based on its structural setup, can be categorized into the following types:What is Lava Made Of

Felsic Lava

Felsic lava is extremely thick and volatile in nature.  Felsic eruptions occur at temperatures between 1200°F to 1400°F. Felsic lava's flow forms lava spines or lava domes. Felsic lava eruptions typically occur due to the flare-up of hot spots in the continental crust. Felsic lava contains aluminium, potassium, sodium and calcium which form feldspar and quartz.

Intermediate Lava

Intermediate lava, compared to felsic lava has lower content of silica and aluminium, and more of magnesium and iron. Intermediate eruptions occur at temperatures between 1400°F to 1800°F Intermediate lava's flow forms andesite domes and lava blocks. Intermediate lava is much more liquid in nature and distinctive crystals known as phenocrysts can be found in it.

Mafic Lava

Mafic lava has high content of magnesium and iron. Mafic lava eruptions occur at temperatures greater than 1800°F. Mafic lava, like intermediate lava is liquid in nature and phenocrysts can also be found in it.