Photo: ReutersThe powerful earthquake that struck New Zealand is unusual in that a big event on one fault may have immediately triggered a big event on a second fault, experts say. Monday's 7.5 magnitude quake hit near Hanmer Springs at 12.02 am killing two people, damaging roads and buildings and setting off hundreds of strong aftershocks. A 9.0 magnitude earthquake in Japan in 2011 that also triggered a tsunami and killed thousands of people was preceded by a quake of magnitude 7.3 and three magnitude-6.0 quakes. "It was a tectonic earthquake that was occurring on a plate boundary, which is pretty normal. As a result, New Zealand's earthquake on Monday appeared to be causing aftershocks on two separate fault lines, he said.

Source: Otago Daily Times November 14, 2016 21:24 UTC