What are seamounts?

Source: The post is based on the article “What are seamounts?” published in The Hindu on 28th April 2023

What is the News?

Scientists have reported finding 19,325 new seamounts after poring through new high-resolution data. A 2011 census had already mapped 24,000 seamounts across the world’s oceans.

What are Seamounts?

A seamount is an underwater mountain. They are formed through volcanic activity and scientists recognise them as hotspots for marine life. Like volcanoes on land, seamounts can be active, extinct or dormant volcanoes.

Formation: Most seamounts 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.

Surveyors map seamounts using one of two modes: 1) echo sounders or multibeam sonar on ships for topographic mapping or 2) using satellite altimetry for gravity-field mapping.

What is the importance of Seamounts?

Firstly, since seamounts are formed when the molten rock comes up from below the tectonic plates, they provide information about the mantle’s composition and about how tectonic plates evolve.

Secondly, oceanographers also study seamounts to understand their influence on how water circulates and absorbs heat and carbon dioxide.

Thirdly, seamounts are home to diverse biological communities. They are good places for life because they can cause localized ocean upwelling – the process by which nutrient-rich water from deep within the ocean moves up to the surface.

What is India’s contribution to mapping Seamounts?

SARAL, a satellite that India and France developed together for oceanographic studies made a significant contribution by further reducing radar noise and enabling the expansion of the seamount catalogue.