Seismologists studying the Canterbury earthquakes say aftershocks from the September 2010 quake were so unusually strong because of the type of rocks along the faultline.
Billy Kristian of The Invaders shares his memories of Ray Columbus who has died at the age of 74. Islay Marsden of the University of Canterbury discusses what clearing rocks and silt from quake-induced landslides will do to the coastal environment. Kevin Furlong of Penn State University discusses the connection between the earthquakes and various faultline systems.