Greek islands Santorini on alert as earthquakes shake the area

On the Greek island of Santorini, schools have closed and residents are taking precautions in the aftermath of more than 200 earthquakes over the weekend. The island on the Aegean Sea is a tourist hot spot with millions of visits per year thanks in part to its unique geography. The island's crescent shape formed during one of the largest volcanic eruptions in recorded history. The World's Marco Werman gets perspective on the latest earthquake news from seismologist Nikos Theodoulidis, who joined the show from the Institute of Engineering Seismology & Earthquake Engineering in the Greek city of Thessaloniki.