May 24, 2019

3D Earth gravity map may help predict earthquakes

3D Earth gravity model. It looks a bit like Earth has been left in the fruit bowl a bit too long.

The European Gravity and Ocean Circulation Explorer spacecraft has mapped the Earth’s gravity and produced a 3D model that may help scientists predict earthquakes.

The five-metre GOCE spacecraft has been orbiting Earth at an altitude of 250km since its launch two years ago. It has been mapping Earth’s gravitational pulls and recording its position with GPS, measuring the gravity in 3D accurate to one part in ten million million.

The data it collects shows how the pull of gravity varies minutely over the different surfaces of the earth, from the depths of the oceans to the highest mountains.

Scientists from the European Space Agency have created a computer model called a geoid that shows what the Earth would look like if its shape was altered to make gravity equal at every point.

The strongest gravity is shown in yellow and the weakest in blue.

The ESA Scientists say the geoid will be crucial in measuring ocean circulation, sea-level change and ice dynamics – all driven by gravity – as the planet warms in response to climate change.

And, because Earth’s gravity is affected by any changes in its structure and geography, scientists are also analysing information from the GOCE to get a better understanding of the geological processes that cause earthquakes.

They do this by studying the “signatures” the quakes leave on gravity data.

The recent earthquake in Japan was triggered by the sudden movement of tectonic plates beneath the ocean.

Because the earthquake was caused by tectonic plate movement under the ocean, the motion cannot be observed directly from space.

However, earthquakes create signatures in gravity data, which could be used to understand the processes leading to these natural disasters and ultimately help to predict them, the ESA scientists believe.

Newswarped gets excited with anything that helps us understand the world we live in better. Well done to the ESA for undertaking the project sharing its progress with all of us.