Strong shallow earthquakes in South Island

Two strong, shallow earthquakes near Haast on the West Coast early today reportedly caused minimal damage, but were felt as far away as Christchurch.

The first quake, measuring 6 on the Richter scale, struck at 3.35am 10km south of Haast, the second five minutes later measured 5.7 and was 10km southwest of the town. Both were between 10km and 15km deep.

Institute of Geological and Nuclear Sciences seismologist Ken Gledhill told NZPA the quakes appeared to have been strongly felt in Haast.

"But I think they're rugged individuals there. I talked to someone who runs a motel there, who said it was a decent earthquake but no real damage. It sounded like some goods off shelves."

The centres of the two earthquakes had been close together and close to the Alpine Fault, which ran almost the length of the South Island, Dr Gledhill said.

But today's quakes appeared to be a kind of pushing up motion, rather than along, so were probably not directly related to the fault.

The second earthquake was larger than normal for an aftershock, but otherwise there had been fewer and smaller aftershocks than would have been expected.

A couple of magnitude 3 aftershocks had been felt, but for a shallow magnitude 6 earthquake, several magnitude 5 aftershocks would have been expected, he said.

Scientists were considering whether to move extra equipment to the area to get more information about today's earthquakes, but that would only be worthwhile if there were many aftershocks.

The quake was strong enough to wake people on the other side of the South Island. The first shake was felt in Christchurch, 360km from Haast, as a strong, sharp swaying for about 10 seconds. The aftershock was felt for about five seconds.

- NZPA, HERALD STAFF