SCOTS scientists have used an advanced rock-dating technique to alert residents on a remote South Atlantic island of impending volcanos.
In 1961, a volcanic eruption led to the total evacuation of Tristan da Cunha, the most remote inhabited archipelago in the world, with residents moved to temporary accommodation in the UK.
The island, with a population of 261, is a British territory with only one village, which is called Edinburgh of the Seven Seas. The land mass is the tip of an undersea volcano and is seven miles across.
Following their evacuation, families decided to return home in 1963. However, the volcano is still active and as recently as 2004 an undersea eruption washed volcanic rock on to the island’s shores.
Now scientists at the University of Glasgow, the British Geological Survey in Edinburgh and a team at the University of East Anglia have used a method known as argon-argon dating which shows eruptions are more common than previously thought.
A paper published in the journal Geology reveals that, although the scientists cannot give exact predictions, they have helped islanders be more aware of the risk of eruptions and encouraged them to review their disaster management plans.
Dr Darren Mark, of the Scottish Universities Environmental Research Centre based at the University of Glasgow, said: “By examining rock samples, we can measure its ratio of radioactive potassium to argon, which is its decay product. We know that the half-life of this decay process is 1.25 billion years, so basically the older a rock is, the more argon we’ll find.
“We dated samples from as long ago as around 118,000 years to as recently as 3,000 years and discovered eruptions are much more frequent and recent than previously suspected.”