The above video, from the day of the quake, shows many of the buildings where hundreds were trapped, and where many died.
A detail from a larger image of Christchurch shortly after the February 22 quake struck :
Rebuilding continues.
Mr Ring, who lives in Auckland, uses the moon, sun and tidal activity for the basis of his theories, which have been dismissed by scientists.His warning is clear.
"If I lived in Christchurch, I'd get out for a few days over that time, go camping, visit friends, just get out and keep safe," he said.
"And if you don't live there, stay away."
Mr Ring claims he got it right last time :
On Valentine's Day, he issued a tweet stating that conditions were "potent" for a quake in Christchurch between February 15 and 25.The day when scientists can accurately predict the eruption of an earthquake below a city will be one of the pinnacles of our understanding of this planet's thin, unstable skin that we base our entire existence upon.
A 6.3-magnitude earthquake struck on February 22, killing as many as 240 people.
Eerily, he warned people to watch for "special signs", such as silent birds or scared pets, and said "stay away from old cracked buildings".
Blogger Peter Hyde, who lives in the south-east of Christchurch, said he was living in "refugee city".
It was populated by 50,000 to 100,000 people who have been living on broken streets with little access to power, water, gas and other services, he said.
"Their houses may or may not be intact. Their streets may be clear, broken, or full of silt. Or sewage. There are no showers. Or ways to wash clothes. Or to wash dishes. Or to heat the "must boil" water that is available - assuming they can make it to the nearest water truck, day after day. No refrigeration. No working toilets, and precious few portaloos. No face masks to defend against the blown silt.
"They have no internet either, and usually no phones. And their radio batteries are dead or dying."
"It was extremely violent. I was sitting there with a friend and the building just like exploded. It was like a movie. It took two or three seconds to comprehend what was going on ... and then we ran onto the street and the front fell out of the building right in front of me."
"It was just scary. [The cathedral], it just came down, like shit, within about two seconds. Unbelievable, unbelievable."
"It was very, very strong, I was up on the top floor of the council building and I got thrown quite a distance. I got down to the street, scenes of great confusion, some very, very upset people, a lot of people crying. I know of people in our building that have been injured." -
"I was in the square right outside the cathedral - the whole front has fallen down and there were people running from there. There were people inside as well."