Fiordland continues to rumble

Earthquakes felt in Fiordland and the West Coast on Saturday are believed to be aftershocks of a large quake that rocked the southern South Island last year.

Te Anau was shaken by two earthquakes in quick succession, while a third shook the West Coast in the early afternoon.

The first, measuring 4.7 on the Richter scale, struck at 9.36am.

It was centred 80km west of Te Anau at a depth of 12km.

The second, two minutes later and measuring 4.1, was centred 70km west of Te Anau also 12km deep, GNS Science said. At 12.39pm, a 4.1 quake hit 60km southwest of Haast at a depth of 5km.

GNS Science geologist Dr Gill Jolly said aftershocks of the 7.8 earthquake centred 100km southwest of Te Anau that struck on July 15 last year were still being felt.

"Last year's quake was the most powerful felt in New Zealand since the Napier quake in the 1930s.

"Saturday's tremors were part of the ongoing aftershocks of that quake," Dr Jolly said. GNS still has researchers specifically working on why last year's quake did not cause more damage.

Dr Jolly said that links to worldwide earthquake trends were hard to establish.

"There have been some significant earthquakes in the last year. Samoa, Vanuatu and Haiti have been hit by very powerful quakes, but any global links or patterns are very had to establish."

She said that earthquakes could happen anywhere, any time.

"Everyone in New Zealand should have an emergency kit set up, even people in areas not traditionally hit by earthquakes."

The aftershocks should subside over time, but a steady decrease could not be guaranteed, Dr Jolly said. "The effects of last year's quake could last a few more months, but another earthquake could happen that would generate its own aftershocks, so people just have to be prepared as best they can," she said.

No damage was reported from yesterday's quake.

grant.bryant@stl.co.nz