Coral's climate change clues

Dr Nicola Allison diving for coral in the Pacific Ocean

Corals from the depths of tropical waters may help scientists understand how rapidly the earth's climate has changed over thousands of years.

Experts at the University of St Andrews have said their research could also uncover information which may be helpful in predicting climate change in the future.

The scientists have been awarded £145,000 by the Natural Environmental Research Council (NERC) for a two year study into the way in which coral skeletons encode climate change over thousands of years.

Close-up shot of the surface of a coral skeleton

Marine biologist Dr Nicola Allison, the researcher in charge of the project, used her diving skills to gather coral samples from the Pacific Ocean off Hawaii.

She said: "We will use the chemistry of coral skeletons to tell us about conditions in the past.

"This could tell us how rapidly climate change has occurred and help us to predict the likelihood of changes in the future.

"We are particularly interested in the element strontium (similar to calcium), which is found in corals, for example how does it get there, how does it vary according to sea temperature.

"We collected samples during the day and night as we know that corals precipitate differently depending on the time of day.

Coral fossils can be up to 100,000 years old

"We also know that coral usually grows more rapidly over warm seasons."

The team will use advanced X-ray equipment to study four coral colonies in 3D, similar to the processes used to age trees.

Corals are sliced and X-rayed and each section holds information on age and climate.

Most corals live for between 200 and 300 years but coral fossils up to 100,000-years-old could be used to uncover long-term sea temperature change.