New Zealand quake moves country
Thursday, July 23, 2009
WELLINGTON, New Zealand -- Southern New Zealand has moved slightly closer to the east coast of neighboring Australia as a result of an earthquake last week, a scientist said Wednesday.
The magnitude 7.8 quake, centered in the ocean near Resolution Island, twisted South Island into a different shape and moved its southern tip 12 inches closer to Australia, seismologist Ken Gledhill said.
Gledhill, director of government-owned GNS Science's "GeoNet" national earthquake monitoring project, said the island's geographic shift showed the immensity of the forces involved.
"Basically, it's taken us closer to Australia," he told National Radio. "The country is deforming all the time because of being on the plate boundary, but this has done it in a few seconds, rather than waiting hundreds of years."
Last Wednesday's quake was the largest in the world this year and New Zealand's biggest in 80 years. No major damage has been found in the sparsely populated Fiordland region of South Island's west coast.
"New Zealand has been very fortunate. This earthquake anywhere else would have caused huge damage," Gledhill said. He said the quake's impact will provide "invaluable information" on the underlying structure of the country.
Martin Reyners, principal scientist for GNS Science, said earlier that a shallow temblor of such magnitude would typically cause widespread damage and loss of life. Last week's quake, however, occurred in "soft rocks" between two tectonic plates, muffling its power, he said.
Reyners said the rocks had lurched rather than snapped, causing a low-frequency rolling rather than the high-frequency waves that are known to damage buildings.