A 7.8 magnitude, most powerful and scariest earthquake hit the south coast of New Zealand, on November 16. It’s the most complex ever recorded earthquake. GeoNet (national quake-monitoring body) reports says that the combination of two quakes lasted two minutes, with the most severe shaking at around 50 seconds. It brought life to a halt because of its devastating impact and left fractured roads, a distressed population and total chaos.
This quake hit the seabed hard enough to split it and leave it floating towards the surface. It was type of reverse faulting observed in the February 22, 2011, Christchurch Earthquake.
In New Zealand’s case, there’s a continual scrum going on between the Pacific Plate and the 47-million square kilometre Australian Plate right along the curving boundary. They collide differently in different places.
GNS Science report says this burst could have produce one of the biggest earthquakes since European settlement of New Zealand, and would have a “major impact” on the lives of many people. Thousands of landslides and hundreds of tremors after the quake has been reported.
New Zealand is on the boundary of the Australian and Pacific tectonic plates, which form part of the so-called “Ring of Fire”, and experiences up to 15,000 tremors a year.
The quake generated a tsunami and an evacuation of coastal areas. The tsunami didn’t cause serious damage, except to one area called Little Pigeon Bay on Banks Peninsula as per Geonet reports.
Most earthquakes are the result of split on a single fault plane. But these twin quakes led to the split of at least six faults, including a newly identified one at Waipapa Bay. Due to reverse faulting a section of the seabed along a 110km stretch of coast north of Kaikoura was lifted by between 2-2.5m.
But the whole country was rattled, with the impact seen over a 7,000 sq km area. Considerable damage caused to the roads and dozens of buildings in Wellington, the capital. Residents reported being woken up by shaking. Two people were killed. Air force helicopters are mounting rescues. Residents and Tourists are told to conserve food and water supplies.
The seabed rise, marooned 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.
The total damage is anticipated to be at least NZ$12bn ($8.4bn; £6.8bn), and emergency work is expected to continued for some time.
In the interim aftershocks are reported around 2000 and scientists say more quakes are expected.