New Zealand's earthquakes

From BBC
New Zealand quake: The geological impact of a 'complex' tremor
The powerful earthquakes which hit New Zealand were some of the most complex ever recorded, say scientists.

Earthquakes are caused by a sudden slip on a fault, the fractures in Earth's crust. There are three types of faults: strike-slip, normal and reverse faults. These faults indicate different movements of rocks.

Tonkin and Taylor, an engineering firm surveying the damage, said a section of the seabed along a 110km stretch of coast north of Kaikoura was lifted by between 2-2.5m. Prof Nicol said this was likely due to "reverse faulting".

The seabed rise stranded huge amounts of marine life, including crayfish and paua - an edible sea snail harvested for its meat and shells. Experts say it could take years for the wildlife to recover, a serious concern for the fishing industry.