Earth’s gravity scar



 
The Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) mission will measure high-accuracy gravity gradients and provide a global model of the Earth's gravity field and of the geoid. The geoid (the surface of equal gravitational potential of a hypothetical ocean at rest) serves as the classical reference for all topographical features. The accuracy of its determination is important for surveying and geodesy, and in studies of Earth interior processes, ocean circulation, ice motion and sea-level change.


 
The upward and downward displacement of the seafloor during the 28 December 2004 earthquake caused a change in the Earth¹s geoid.

The surface moved by around six metres and this caused the geoid to change by 18 millimetres.
The changes to the geoid are shown here with upward geoid movements in red and downward ones in blue.

Artist's impression of GOCE satellite
 
Artist's impression of GOCE (Gravity field and steady-state Ocean Explorer) satellite. GOCE is the first Core Earth Explorer satellite to be developed as part of ESA’s Living Planet Programme.



Release date: 14 February 2008