Newly Discovered 19,000 Underwater Volcanoes Unveiled by Satellite Data Across the Globe.

A new study has identified more than 19,000 previously unknown volcanoes or seamounts underwater in the world’s oceans.

Oceanographers from the Scripps Oceanographic Institution, in collaboration with researchers from Chungnam National University and the University of Hawaii, have mapped 19,000 previously unknown seamounts around the world using radar satellite data.

In their paper, published in the journal Earth and Space Science, the group describes how they have used satellite-based sea-mound radar data to search for and map underwater volcanoes and explain why this is so important.

The bottom of the ocean, like the land, has a diverse topography. As in the case of land, mountains stand out in particular, and in the ocean they are called seamounts. They can be formed by tectonic plates colliding with each other and forming folds, or by volcanic eruptions forming cones.

Currently, only a quarter of the sea floor is mapped, which means that no one knows exactly how many seamounts there are and where they might be.

This can be a problem for submarines, as, for example, American submarines have hit seamounts twice, which can pose a danger to these ships and their crews. But not knowing where the seamounts are is another problem that prevents oceanographers from creating models depicting how ocean waters flow (currents) around the world.

In this new work, the research team has set themselves the task of discovering and mapping as many seamounts as possible. To do this, they used data from radar satellites.

Such satellites, of course, cannot see seamounts, instead they measure the height of the sea surface, which changes due to changes in gravity associated with the topography of the seabed, an effect known as sea embankment. In doing so, they discovered 19,000 previously unknown seamounts.

In their paper, the team notes that important reasons for mapping the ocean floor are things like helping to extract minerals from the seabed, as seamounts contain vast amounts of rare earth minerals.

More complete seamount maps will also help geologists map more accurately the planet’s tectonic plates and geomagnetic field. Some seamounts are also home to a wide variety of marine life.

But most importantly, it has a very strong influence on the flow of the ocean in the deep sea. When currents collide with seamounts, they are pushed up, dragging cold water with them and mixing in unknown ways.

Mapping these currents is becoming increasingly important as the oceans absorb more heat and carbon dioxide from the atmosphere and fresh water melts due to ongoing climate change.

Source: phys.org.