<http://schema.org/alternativeHeadline>
"Researchers took samples from sediment and wood to trace how often quakes struck to determine if fault lines have any pattern in their activity."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/earth-matters/wilderness-resources/stories/san-franciscos-deadly-1906-earthquake-was-last-of-three>