WELLINGTON • Two earthquakes struck New Zealand yesterday, with a 5.6-magnitude tremor rattling the North Island and a 5.7- magnitude quake shaking the South Island hours later.
No major damage was reported.
The tremors came a little more than a week after a 7.8-magnitude quake centred in the upper South Island rocked the country and killed two people.
That quake, one of the most powerful recorded in the country, triggered thousands of landslides, blocked roads and rail lines and lifted the seabed in some areas out of the water.
The quake badly affected the coastal town of Kaikoura to the north of Christchurch, and thousands of aftershocks have been registered since then.
Yesterday's North Island quake was centred off the east coast 138km from Palmerston North at a depth of 37km and was felt in the capital Wellington.
The second quake hit in the evening 20km south-east of the town of Culverden.
Earthquake scientist John Townend of Victoria University told the New Zealand Herald that no one should draw any connection between yesterday's earthquake in Japan and the Kaikoura quake.
"The basic explanation of the earthquake in Japan is they had a magnitude-9.0 quake in 2011 and a magnitude 9 generates large aftershocks and an extended aftershock sequence," he said. "So we are just seeing that ongoing activity in that part of the world."
Dr Townend also said New Zealanders should not see a link with the 2011 Japan earthquake and tsunami and the 2010 and 2011 Canterbury and Christchurch quakes. He said there was no evidence to suggest any elevated activity across the Ring of Fire, which refers to tectonic plate boundaries around the Pacific that trigger earthquakes and volcanoes.
"Patterns are very hard to detect from big quakes because they happen so infrequently," he said.
"So when you have two in close proximity, it seems natural to draw a conclusion about there being an elevated rate - but as far as I'm aware, there's no evidence for that."