A subduction zone-style earthquake is what was thought to cause the tsunami that struck the eastern coastline, as only this type of fault – where one slides down over another – can move so much water as to cause a tsunami.
Waves reached a height of 2 meters (6.6 feet). For comparison, the tsunami that hit Japan’s eastern seaboard in 2011 were up to 39 meters (128 feet), so things could have been far worse.
The event took place across an area of about 12,000 square kilometers (4,633 square miles), and was felt particularly strongly in Christchurch – still recovering from the devastating 2011 event – and Wellington.
“I was on the third level of my flat when I felt the earthquake,” Dr Manda Safavi, a scientific advisor to the Environmental Protection Authority in Wellington, told IFLScience. Describing the “continuous aftershocks,” she said that “this has been the longest twenty-four hours of my life.”
Some unfortunate cows were stranded after the primary earthquake caused a few landslides. Associated Press via YouTube
Destroying plenty of infrastructure, and even cutting off the town of Kaikoura through landslides, it was the most powerful quake in the region since 1929. Disconcertingly, the location of the earthquake may mean that the danger will not be over for some time.
“Because of the complexity of this plate boundary region, strain is being accommodated on many different structures of varying orientations, making it possible that more than one fault may be activated in this earthquake sequence,” the USGS said in a statement.