InfrastructurePredicting earthquakes and volcanic eruptions

Published 10 April 2008

New satellite will measure anomalies in the Earth’s gravitational field; such anomalies allow scientists to predict earthquakes and volcanic eruptions, and allow communities to better prepare for them

Knowledge is power. One way to predict the imminence of an
earthquake or a vulcanic eruption is the measure changes in the Earth’s gravity
field, but to date scientists have not had very accurate means to measure such
changes. A new satellite which will measure the Earth’s global gravity field
considerably more accurately than is currently achievable by other satellite
and terrestrial means is being prepared for launch in Russia at the end of May. Part of the European Space Agency’s Living Planet
Program, the GOCE mission (Gravity Field and Steady-State
Ocean Circulation Explorer
) will help U.K. researchers to locate
gravity anomalies around the world and link them to the deep Earth processes
that cause earthquakes and volcanic activity.

GOCE will skim the edge of our
atmosphere, orbiting at a low altitude where the satellite will be sensitive to
the strongest possible gravity field signal. For the first time a gradiometer
will be used in space so the measurements will be far more accurate,” said
Professor Philip Moore from Newcastle
University
, who specialises in gravity
 research.

The gradiometer is based on six
ultra-sensitive accelerometers and is able to achieve very accurate
measurements. GOCE will gather the data at an altitude of around 270 km above
the Earth and will capture spatial scale measurements at around 100 km. The
best scale measurement that can be obtained from existing satellites is around
600 km. The mission has a limited life-span of about twenty months, and once
the satellites’ fuel has been used up, it will be allowed to fall to Earth
where it will burn up in the atmosphere. “This is a very challenging
mission as GOCE will be constantly battling against the effects of air-drag to
obtain these measurements. However, the benefits to researchers will be vast.
It will provide us with a better understanding of ocean circulation and
volcanism and even the processes that lead to accumulation of stresses and the
triggering of earthquakes,” Moore added.