A team led by Australian National University researchers has solved the mystery behind the world's largest and most active volcanoes in Hawaii. The study used computer simulations to determine that the twin tracks that caused the volcanoes are due to a shift in the Pacific Plate's motion three million years ago. <br/><br/>Lead researcher Tim Jones said the discovery would help scientists better reconstruct Earth's history. <br/><br/>Scientists have known of the existence of the twin volcanic tracks since1849 but their cause had remained a mystery until now.