Seamounts

About Seamounts:

• It is an underwater mountain formed through volcanic activity.
• These are recognised as hotspots for marine life. Like volcanoes on land, seamounts can be active, extinct or dormant volcanoes.
• These are formed near mid-ocean ridges, where the earth’s tectonic plates are moving apart, allowing molten rock to rise to the seafloor.
• The planet’s two most-studied mid-ocean ridges are the Mid-Atlantic Ridge and the East Pacific Rise.
• Some seamounts have also been found near intraplate hotspots – regions of heavy volcanic activity within a plate – and oceanic island chains with a volcanic and seismic activity called island arcs.
• Significance of seamounts
  • They provide information about the mantle’s composition and how tectonic plates evolve.
  • Oceanographers also study seamounts to understand their influence on how water circulates and absorbs heat and carbon dioxide.
  • Seamounts are home to diverse biological communities. They are good places for life because they can cause localised ocean upwelling – the process by which nutrient-rich water from deep within the ocean moves up to the surface.

Key Facts about the Mid-Atlantic Ridge

• It is the largest geological feature on the planet. 
• It is a mostly underwater mountain range in the Atlantic Ocean.
• It is about 3 km in height above the ocean floor and 1000 to 1500 km wide, has numerous transform faults and an axial rift valley along its length.
• It separates the North American Plate from the Eurasian Plate in the North Atlantic and the South American Plate from the African Plate in the South Atlantic

 

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Q1) What is mantle?

The mantle is a layer of the Earth's interior that lies between the crust and the core. It is the largest layer of the Earth by volume and makes up about 84% of the Earth's total volume. The mantle is composed of silicate rock that is denser than the crust, and it has a thickness of about 2,900 kilometers (1,800 miles).

Source: Science for All | What are seamounts?