A volcano is a unique landform created by the eruption of high-temperature magma, gases, and debris from weak points in the Earth's crust.

Volcanoes are unevenly distributed across the Earth, with most located along plate boundaries and a few within tectonic plates. These form the four major volcanic belts: the Pacific Rim Volcanic Belt, the Mid-Ocean Ridge Volcanic Belt, the East African Rift Valley Volcanic Belt, and the Alpine-Himalayan Volcanic Belt. The Pacific Rim Volcanic Belt alone contains over 300 active volcanoes, accounting for about 60% of the global total.

Volcanoes aren't limited to land; in fact, about 75% of volcanic activity occurs in the oceans. Submarine volcanoes, often called seamounts, form when magma erupts through cracks in the Earth's crust and cools. These underwater volcanoes can create large volcanic islands, such as the Hawaiian Islands, and deep-sea hydrothermal vents, which are home to unique and exotic creatures. While submarine volcanic eruptions typically don't pose a direct threat to humans, they can sometimes cause tsunamis, earthquakes, or even influence climate change.

Formation and eruption

Magma is highly active within the Earth's interior. It can sometimes intrude into rock formations or erupt violently to the surface. When magma rises slowly and encounters a weaker area in the Earth's crust, it erupts through that point, a process known as a volcanic eruption. After the eruption, the magma cools and accumulates near the vent, gradually forming a hill-like structure that becomes a volcano.

Volcanic eruptions can also occur due to the formation of magma chambers in subduction zones or collision zones of tectonic plates. In these areas, local high temperatures are generated by friction, and the dehydration of water-bearing minerals lowers the melting point of rocks, contributing to volcanic activity.

Most common shape

- Shied Volcano

Repeated volcanic eruptions produce extensive lava flows, often composed of basalt, which create mountains with broad summits and gently sloping sides.

Famous shield volcanoes include Kilauea in the Hawaiian Islands and Mauna Loa.

- Composites Volcano

Formed by alternating eruptions of lava flows and volcanic debris, these volcanoes differ from shield volcanoes in that their lava is more viscous and flows only short distances from the crater. Pyroclastic material and pyroclastic flows accumulate around the volcano, creating a stratified structure.

- Cinder Cone

Volcanic cinders and bombs are ejected from the crater, while fine-grained volcanic ash drifts away. Sometimes lava flows out from the base of the cinder cone. These types of volcanoes are relatively small in size, and most erupt only once.

Positive and negative effects of volcanoes

Volcanic eruptions are highly destructive to humans, causing natural disasters such as mudslides, lava flows, and landslides. They release large amounts of gases that can suffocate people and damage the ozone layer, posing a serious threat to humanity today.

While volcanic eruptions can be catastrophic, they also create stunning natural landscapes and valuable resources. Eruptions form diverse landforms such as volcanic islands, crater lakes, lava plains, lava caves, hot springs, and geysers, which offer significant aesthetic appeal and contribute to rich ecosystems and tourism opportunities. Additionally, volcanic activity leads to the formation of various minerals, including metals, gemstones, coal, and oil, which are economically valuable and essential for industrial and energy needs.

After a volcanic eruption, magma remains a valuable source of geothermal heat as long as it stays beneath the surface. Hot springs and geysers often form near volcanoes due to the heat from the magma warming the groundwater. This heat source, known as geothermal energy, can lead to the development of extensive geothermal fields.