UNDERWATER VOLCANOES

 UNDERWATER VOLCANOES: CHIMNEYS IN UNDERWATER WHICH EXPLODE WITH LAVA AND VAPOUR. 🌋

Underwater volcanoes, also known as submarine volcanoes, are fascinating geological formations that occur on the ocean floor. Most submarine volcanoes are located in the depths of seas and oceans, some also exist in shallow water, The total number of submarine volcanoes is estimated to be over one million (most are now extinct) of which some 75,000 rise more than 1 kilometre (0.62 miles) above the seabed. 

They play a crucial role in shaping the seafloor and influencing oceanic ecosystems. These structures can be found in various underwater environments, including along tectonic plate boundaries, hotspots, and mid-ocean ridges.

 These submarine volcanoes are formed when the tectonic plates shift, creating fractures in the Earth’s crust and allowing it to escape magma. These eruptions often occur along mid-ocean ridges, where tectonic plates are pulling apart, or at subduction zones, where one plate slides beneath another  .These volcanoes can be active or extinct. 

 For instance, water causes magma to cool and solidify much more quickly than in a terrestrial eruption, often turning it into volcanic gases and causing explosive eruptions. Upon contact with water, a solid crust forms around the lava. Advancing lava flows into this crust, forming what is known as pillow lava. Some underwater volcanoes grow tall enough to eventually break the surface, forming volcanic islands, such as the Hawaiian Islands. 

 Many submarine volcanoes host hydrothermal vent systems, which are conduits in the Earth's crust where mineral-rich hot water is released. The sulfur and iron from hydrothermal vents contribute to nutrient cycles that support marine life. These vents support unique ecosystems that rely on chemosynthesis rather than photosynthesis.

The hot, mineral-rich water expelled from these vents provides nutrients for bacteria that form the base of the food chain, supporting creatures like giant tube worms, crabs, and unique fish species. While submarine eruptions can be destructive, they also create new habitats and support diverse ecosystems. The minerals from volcanic eruptions provide essential nutrients for plankton and other organisms. Volcanic islands and seamounts (underwater mountains) also serve as hotspots for biodiversity, offering unique habitats for marine species.

Large underwater eruptions can trigger tsunamis, massive waves caused by sudden displacement of water due to eruptions or landslides. While most submarine volcanic eruptions are minor, some can be explosive and affect coastal areas if they occur near land.

Exploring underwater volcanoes is challenging due to extreme depths, high pressure, and temperatures. Studying underwater volcanoes helps scientists understand tectonic processes, the formation of Earth’s crust, and the potential for life in extreme environments.

 

Imalka Edirisuriya.

2nd Year (21/22).