STSE Videos > MAPPING THE MOHO WITH GOCE

MAPPING THE MOHO WITH GOCE

The first global high-resolution map of the boundary between Earth.s crust and mantle . the Moho . has been produced based on data from ESA.s GOCE gravity satellite. Understanding the Moho will offer new clues into the dynamics of Earth.s interior.

Earth.s crust is the outermost solid shell of our planet. Even though it makes up less than 1% of the volume of the planet, the crust is exceptionally important not just because we live on it, but because is the place where all our geological resources like natural gas, oil and minerals come from.

The crust and upper mantle is also the place where most geological processes of great importance occur, such as earthquakes, volcanism and orogeny.

Until just a century ago, we didn.t know Earth has a crust. In 1909, Croatian seismologist Andrija Mohorovi.i. found that at about 50 km underground there is a sudden change in seismic speed.

Ever since, that boundary between Earth.s crust and underlying mantle has been known as the Mohorovi.i. discontinuity, or Moho.

Even today, almost all we know about Earth.s deep layers comes from two methods: seismic and gravimetric.

Seismic methods are based on observing changes in the propagation velocity of seismic waves between the crust and mantle

Gravimetry looks at the gravitational effect due to the density difference caused by the changing composition of crust and mantle

But the Moho models based on seismic or gravity data are usually limited by poor data coverage or data being only available along single profiles.

Animation by Planetary Visions