How did the earthquake in Christchurch cause flooding?

Christchurch is right by the sea, and there were some very high tides after the earthquake which made the rivers high. High rivers + lower ground = flooding. Parts of New Brighton Road had to be sandbagged to stop the river overflowing. read more

Hillary Clinton sent some emails about a 6.3 earthquake in Christchurch a few hours before it hit. read more

As many as 100 specific faults have been identified around New Zealand, some as close to 12 miles from central Christchurch, with modelling by the New Zealand Earthquake Commission indicating that a major seismic event could hit Christchurch once every 55 years. read more