Volcanologists earn their crust

Scientists from Durham University have set off to explore the depths of the Atlantic Ocean to study the growth of underwater volcanoes that build the Earth’s crust.

RRS James Cook will play host to the intrepid volcanologists

The experts will lead an international team of 12 scientists aboard Britain’s Royal Research Ship (RRS) James Cook and plan to use robots to aid their exploration.

During the five-week expedition they will use explorer robots to map individual volcanoes on the Mid-Atlantic Ridge tectonic plate boundary - which effectively runs down the centre of the Atlantic Ocean - almost two miles below the surface of the sea.

Principal investigator Professor Roger Searle, of the Department of Earth Sciences at Durham University, said: “The problem is that we don't know how fast these volcanoes form or if they all come from melting the same piece of mantle rock.”

They will also use another robot, called ISIS, to collect rock samples from the volcanoes which will be dated using various techniques to shed more light on the timescales behind the growth of the Earth's crust and the related tectonic plates.

“The ridges may form quickly, perhaps in just 10,000 years (about the time since the end of the last Ice Age) with hundreds of thousands of years inactivity before the next one forms, or they may take half-a-million years to form, the most recent having begun before the rise of modern humans,” said Professor Searle.

The team will date the volcanoes using radiometric dating and by measuring the changing strength of the Earth’s magnetic field through time as recorded by the natural magnetism of the rocks.

Understanding the processes forming the crust is important, as the whole ocean floor - 60% of the Earth’s surface - has been recycled and re-formed many times over the Earth’s history.

Professor Searle’s team will include scientists from the National Oceanography Centre Southampton, the Open University, the University of Paris and several institutions in the USA.