http://seattletimes.nwsource.com/html/localnews/2014779024_bigquakes15m.html First came 2004's killer quake and tsunami off Sumatra. Then a year ago, Chile was rocked almost as hard. Now Japan is reeling from its biggest quake in recorded history. The juxtaposition of three of the world's most powerful earthquakes within a span of seven years has some scientists asking the question: Are we in an age of megaquakes?