SAN FRANCISCO The magnitude-7.8 Kaikoura earthquake that rattled New Zealand last month may have set up the country for another major quake underneath its capital of Wellington.

In the next year, there is a nearly 5 percent chance that a magnitude-7.8 or greater earthquake will strike the southern tip of New Zealand’s North Island, Bill Fry, a seismologist and tectonophysicist with GNS Science, a geoscience consultancy service, said Tuesday here at the American Geophysical Union’s (AGU) annual meeting.

That risk comes, in large part, from the wonky way last month’s quake ruptured faults in the area: Instead of rapidly releasing the stress on the ruptured faults , the temblor produced a kind of slow-motion, silent earthquake that is known to increase the risk of future seismic events, Fry said. [ Image Gallery: This Millennium’s Destructive Earthquakes ]

Complex cataclysm