Massive &#39;ocean&#39; discovered towards Earth&#39;s core 12 June 2014 by Andy Coghlan A reservoir of water three times the volume of all the oceans has been discovered deep beneath the Earth&#39;s surface. The finding could help explain where Earth&#39;s seas came from. Blue lagoon: this crystal of blue ringwoodite is being crushed in a lab experiment. (Image: Steve Jacobsen/Northwestern University)