A satellite reveals the remains of continents lost under Antarctica

The researchers discovered remains of lost continents hidden at the bottom of the Antarctic ice using gravimetric data from the GOCE satellite of ESA.

The GOCE (Ocean Circulation Exploration) satellite orbited the Earth for more than four years from 2009 to 2013. Using the GOCE gravity data set, researchers gained new information on structure and properties. of Antarctica, one of the most important. but the least understood parts of the Earth.

GOCE examines landmasses by measuring changes in the Earth's gravity field. As the masses in the continents and in the depths of the Earth's interior are neither coherent nor evenly distributed, the gravitational force varies from one place to another and these gravity anomalies can be used to solve structures deep beneath the surface.

During its four-year mission, GOCE flew over an altitude of only 255 km, more than 500 km closer than normal Earth observation satellites, and measured the Earth's gravity with greater precision than any other mission. This distance also allowed the GOCE satellite to take very accurate measurements of the Earth's gravity over Antarctica, a relatively difficult place due to its remoteness and thick ice cover.

Combined with seismological data, satellite gravimetric data have yielded more accurate 3D maps of the deep interior of Antarctica and provide researchers with an excellent tool for studying the structure of the least-explored region of the world. the planet.

"These gravimetric images are revolutionizing our ability to study the least understood continent of the planet, Antarctica," said co-author Fausto Ferraccioli, chief scientist of geology and geophysics at the British Antarctic Survey (BAS).

"In East Antarctica, we see an exciting mosaic of geological features that reveal fundamental similarities and differences between the crust found under Antarctica and the other continents to which it has been attached until there are 160 millions of years. "

Gravimetric data show that the crust and upper mantle of West Antarctic are thinner than those of the eastern Antarctic, consisting of a mosaic of old cratons separated by younger orogens, thus revealing its links with Africa, India, Australia, Zeeland and South America.

"It is exciting to see that the direct use of gravity gradients, measured for the first time with GOCE, gives an independent new look at the Earth – even under a thick layer of ice," said Roger Haagmans, scientist from ESA's GOCE mission, to ESA. . "It also provides a context of how the continents may have been connected in the past before they split due to the movement of the plates."