Auckland is likely to make a huge economic gain should the Christchurch Rugby World Cup games be relocated, Auckland interest groups say.

New Zealand's Urban Search and Rescue (USAR) team in Japan are settled in the northern part of the country and about to start work helping to find survivors of Friday's magnitude 9.0 earthquake and tsunami.

Christchurch's AMI stadium could be capable of hosting Rugby World Cup matches, Prime Minister John Key said today as the Government studied reports on damage caused by the February 22 earthquake.

A secret report into the state of Christchurch's AMI Stadium reportedly reveals it won't be able to host RWC games, a British news website says.

Live TV coverage from Japanese broadcaster NHK.

The Japan quake was 8000 times stronger than Christchurch's and unzipped a faultline half the size of the North Island, a NZ scientist says.

Yoshimi Okazaki lost her home and job in the Christchurch quake. Now her loved ones are missing in the devastating Japanese quake and tsunami.

Christchurch Mayor Bob Parker says the thoughts of his quake-stricken city are with Japan following Friday's magnitude 9.0 earthquake which devastated much of the country and left thousands dead.

Japanese officials have confirmed a second hydrogen explosion has occurred at the Fukushima Daiichi nuclear power plant, while a warning of a second tsunami has been cancelled.

More than half a million people have been forced from their homes in quake and tsunami-hit northern Japan, petrol has run dry and supermarkets are empty in what its prime minister says is the worst crisis to hit Japan since WWII.