New Zealanders worrying about an earthquake, because of the Sumatra (7.6 magnitude) and Samoa (8.3) earthquakes, could be compared with Dunedin people expecting their house to shake when someone in Oamaru slammed their front door, GNS Science seismologist Bill Fry, of Lower Hutt, said.
Although Samoa and Sumatra were both on the Pacific plate, the earthquakes were unlikely to be linked because they were 10,000km apart, he said.
Melbourne seismologist Dr Gary Gibson told NZPA both the quakes occurred on a common fault line between the Pacific, Australian and Asian tectonic plates.
The earthquakes also occurred on the Pacific Ring of Fire - an area of geological activity stretching from Indonesia to Chile where several plates collide.
Nine out of 10 earthquakes in the world happen in this zone.
"The Samoan earthquake was over 8 [in magnitude] and that's very unusual for that area, but a magnitude 7 off Sumatra happens about every year," he said.
"The fact they occurred within a day could be significant but it might not be - most seismologists say that's too far away for the stress or any plate movement to have a relationship."
Dr Fry said a cluster of large earthquakes happening in a short period was not unheard of and looking at earthquakes going back hundreds of years, the rate had remained fairly stable.
The main concern for the area was the risk of aftershocks.
There had already been several in Samoa, but none was big enough to cause any further damage.
Although people need not be concerned about earthquakes in New Zealand, it was a timely reminder one could strike at any time and people should be prepared, he said.
Pacific shake-up
> In the past 30 days, there have been more than 100 earthquakes in the Pacific area with a magnitude greater than 4.
> There have been 30 earthquakes in New Zealand since August 23.
> The largest was centred 680km northeast of White Island, on September 9, with a magnitude of 6.5.
