Youngest land seen at sea

The ridges seen where the ocean floor is made

For the first time scientists have obtained detailed images of the spreading ocean floor. Our science correspondent David Whitehouse reports.

Most of the surface of our planet is created by molten rock rising to the surface and being pulled in opposite directions by a process known as "sea floor spreading". This creates the youngest land on Earth.

"The sea floor spreading process is like a conveyor belt carrying away crust from mid-ocean ridges," said Donald Forsyth, Professor of Geology at Rhode Island's Brown University and co-ordinator of the project.

Some of the underground and underwater patterns confirm what scientists had suspected about the process. But other details are suprising.

The Mantle Electromagnetic and Tomography Experiment (MELT) is one of the largest marine experiments ever carried out. Its main goal was to find where melted rock, known as magma or "melt" is formed and how it moves.

Lowering the seismometer to the ocean floor

Sensitive detectors were lowered to the ocean floor to monitor the velocity of shock waves through the earth's crust.

From these observations a three-dimensional picture of the structure under the sea floor could be obtained.

Scientists could see the melting rock flowing upwards in a broad zone, rather than in a narrow plume as was suspected.

These new images represent a major step forward in understanding the formation of the Earth's crust.