Can volcanoes only be on land? No, there are also underwater volcanoes whose occurrence exists in deep water bodies as well as shallow water bodies. There are 5,000 or more active underwater volcanoes that have been put on the record. And the biggest underwater volcano that is still active today is the Kolumbo in the Aegean Sea in Santorini island, Greece, whose last eruption happened in 1650. 

Underwater volcanic eruption is the same as that which happens on land. However, the intensity with which the eruption occurs varies variably and is milder in case of underwater volcanoes. Volcanic eruptions in shallow waters shoot rocky debris(碎片), lava(熔岩), and other volcanic material high above the surface of the seas, while volcanic eruptions in deep water bodies don’t shoot the rocky debris and lava in an explosion. In case of large underwater volcanic eruptions, the lava that erupts, solidifies(凝固) immediately after it contacts the water around. These eruptions go on accumulating vertically and become so huge that they might form volcanic islands.

In a land volcano, the liquid lava that erupts reacts actively with the air, changes to gas, and later solidifies. Continuous eruptions like these form layers and cause the formation of huge mountains. In an underwater volcano, the lava that erupts moves in an upward direction. The water has a cooling effect on this liquid lava which causes it to solidify rapidly; so underwater volcanoes are higher than surface volcanoes.

For almost 25 years now, scientists have tried to capture an underwater volcanic eruption on camera and have finally succeeded in doing so. It’s their belief that analyzing underwater volcanoes further will give them a clear insight into: the ways of life and adaptation styles in such extreme conditions; how heat travels from inside the Earth to its surface; and so on.

The Earth is an amazing planet, which never stops surprising us. Although scientists may believe the causes, formation, and volcano-prone regions(火山易发地区) of underwater volcanoes have been thoroughly evaluated, many unexplained phenomena still need to be gauged.