Filling the GOCE data gap unearths South Pole’s geological past

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Publié le 10 mars 2022

It’s very difficult to know what lies beneath a blanket of kilometres-thick ice, so it is hardly surprising that scientists have long contested the shape and geology of the ancient supercontinent from which East Antarctica formed over a billion years ago. An ESA-funded study can now lay some of this conjecture to rest. Using sensors on aircraft to measure changes in the gravity and magnetic signatures of the different rocks under the ice, scientists have discovered a huge bay the size of the UK formed part of the edge of East Antarctica.

Satellites orbiting Earth from pole to pole don’t actually fly directly above the North and South Poles. This leaves two small circular gaps in the global data. To fill in these missing measurements for ESA’s GOCE gravity satellite mission over the South Pole, an international team of scientists joined forces to take a multitude of measurements from aircraft as part of an ESA campaign called PolarGAP.

The GOCE mission mapped Earth's gravity with unrivalled precision and provided the most accurate model of the ‘geoid’ ever produced to further our understanding of how Earth works.

The geoid is the surface of equal gravitational potential defined by the gravity field – crucial for deriving accurate measurements of ocean circulation and sea-level change, both of which are affected by climate change.

It was therefore important to fill in the measurements that GOCE could not take at the poles owing to its orbit.

As well as supplying these missing data for GOCE, the PolarGAP team has yielded new insights into the hidden geology at South Pole, shedding new light on the extent and shape of the edge of East Antarctica.

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