<http://schema.org/alternativeHeadline>
"Underneath the Earth's mantle is a large mass of water that rivals that 'sort of mass of water that's present in all the world's oceans.'"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/earth-matters/wilderness-resources/stories/earth-has-a-secret-reservoir-of-water-and-this-meteorite>