An earthquake on a remote Antarctic archipelago home to 850,000 King Penguins was the strongest on earth in four years, seismologists say.
Macquarie penguins appear to have escaped the worst
The quake hit 400km (250 miles) off the Macquarie Islands on Friday, measuring 8.1 on the Richter scale.
Penguins appear to have escaped a major disaster as the quake occurred deep under the sea, far from inhabited land.
There were no tsunamis, or large tidal waves, because the quake moved horizontally rather than vertically.
The tremors were felt in Tasmania, 1000km (600 miles) away, but because the epicentre was 10km underground, few observers noticed the initial quake.
Buildings on the islands shook for 15 seconds, seismologist Cvetan Sinadinovski said.
10 BIGGEST QUAKES SINCE 1900
Chile, 1960: 9.5
Alaska, 1964: 9.2
Alaska, 1957: 9.1
Kamchatka, 1952: 9.0
Near Ecuador, 1906: 8.8
Alaska, 1965: 8.7
Tibet, 1950: 8.6
Kamchatka, 1923: 8.5
Indonesia, 1938: 8.5
Kuril Islands, 1963: 8.5
Source: US Geological Survey
"If this had happened underneath a population centre it would probably have destroyed a whole city," he said.
The quake was the biggest anywhere on earth since an 8.4-magnitude tremor off the coast of Peru in June 2001. That killed 74 people.
Friday's earthquake was caused by the collision of two of the major tectonic plates which make up the earth's crust layer, the Indo-Australian and the Pacific plates.
The last quake of a similar magnitude in the Macquarie region was in 1924, Mr Sinadinovski said.
Despite its size, 22 staff of the Australian Antarctic Division slept through the tremors.
"Nobody felt anything," a spokesman said.