Geologists have done quite well to link the history of plate tectonics, or how parts of the crust have pinballed…
Geologists have done quite well to link the history of plate tectonics, or how parts of the crust have pinballed all over the world crashing into each other and pulling apart. But there is a big puzzle that they still need to figure out: Antarctica. This is because the continent is covered with a layer of ice on average over a mile thick, which means studying the bedrock directly is almost impossible. But recently, a satellite that measures the dragon of the earth’s gravity could penetrate that ice, reports Hannah Osborne on Newsweek, revealing the tectonic history locked under the frozen continent.
The data came from the European Space Agency’s GOCE (Gravity and Ocean Circulation Explorer) satellite that circled the ground between 2009 and 201
3. During its mission, the craft collected accurate measurements of the earth’s gravity, revealing the thickness and density of the planet’s lithosphere, a combination hull and upper jacket. In the last year of its mission, when it ran out of fuel, operators released the satellite to only 158 miles above the ground to get even better readings before the GOCE burned up.
Since then, researchers have converted data into super-accurate 3D maps on the lithosphere. An exciting discovery, published in the journal Scientific Reports is that the East and West Antarctic cobbles are very different, indicating that the two halves on the continent have divergent stories.
“These gravity images revolutionize our ability to study the least understood continent on Earth, Antarctica,” Geophysicist Fausto Ferraccioli in the British Antarctic Survey and co-author of the paper says in a statement.
In particular, data shows that the crust of the West Antarctica is thinner than the East Antarctica, which consists of a patchwork of old cratons, or the stable pieces of earth crust that make up the nuclei of the continents, held together by younger orogenes or mountain belts. The more complex east seems to be strongly linked to the dissolution of the super continent Gondwanaland 160 million years ago.
“The new pictures show us the fundamental difference in the East and West Antarctic lithosphere in accordance with previous seismic findings.” Ferraccioli tells Osborne. “We also found a greater degree of complexity in the interior of East Antarctica than is evident from current seismic views, which indicates that this part of the continent is a mosaic of old craters and anxieties. Some of these regions have clear ties to earlier adjacent continents in the super continent Gondwana-like Australia, India and Africa. “
The new maps will help researchers figure out how the old pieces and continents fit together and move over time. But the maps have more than historical interest. Knowing what is under the ice will help researchers to understand their behavior and how the bedrock will respond, as climate change starts to melt the ice, which causes the cradle to return upwards.
The gravity map is not the only recent study revealing geology in the frozen south. Another map compiled by the British Antarctic Survey and its co-workers in July combined 50 years of magnetic anomaly data collected across the continent. These data help researchers to create detailed maps of subglacial mountain ranges and other features that are stuck under the ice. Combined, these and other studies begin to give us our first true picture of a continuation