New Gravity Map Reveals Lumpy Earth
The best map yet of Earth's gravity field can help track ocean currents and study the forces behind major earthquakes, experts say.
Released last week, the gravity map is what's known as a geoid, and it was created by a European satellite called the Gravity field and steady-state Ocean Circulation Explorer, or GOCE.
In general, most people think of Earth as a relatively smooth orb. But matter is not evenly distributed across the planet's surface, and bodies of water are constantly shifting due to winds and currents.
By capturing the planet's gravity rather than its physical appearance, the geoid shows the shape that mean sea level would have if it could somehow be extended over the entire surface of the globe, said John Wahr, a geophysicist at the University
