Morning earthquake is upgraded to 8.1 from 7.2 on the Richter scale, making it a "great" earthquake
24 December 2004
Seismologists have upgraded this morning's earthquake in the Southern Ocean to 8.1 on the Richter scale, making it the biggest anywhere for three and a half years.
It was originally reported as being magnitude 7.2 and 450 kilometres west of the Auckland Islands
It hit just before 4 o'clock this morning, lasting about seven seconds..
Duty Seismologist Dr Ken Gledhill says we are lucky it was centred 820 kilometres south of Invercargill.
He says this was a so-called "great" earthquake, and if it had been directly underneath anyone, he says they would have been in deep trouble.
The earthquake caused a small tsunami, measured at 20cm in Bluff.
Dr Gledhill says they have had around 100 reports of the 4 am quake being felt in the South Island and also in Australia.
"Great" earthquakes measure more than 8 on the Richter scale, and when they occur in populated areas, cause great destruction and loss of life.
The famous San Francisco earthquake of 1906 was a great earthquake.
