Earthquake shakes remote Nullabor roadhouse overnight

An earthquake in Western Australia that was picked up by seismometers across the country was only reported to have been felt by one person due to the remoteness of the location.Geoscience Australia said the 4.7-magnitude earthquake was detected near the Cocklebiddy Roadhouse, more than 1,000km east of Perth on the Eyre Highway, about 3am today.Tyson Allamson was one of the only people at the roadhouse, which sits on Australia's iconic Nullarbor Plain."I woke up and was like, 'That's not normal'," Mr Allamson said. "It went for about three minutes, then stopped."There have been no reports of damage.Mr Allamson was the only person to record a "felt" report to Geoscience Australia, which has 100 seismometers to record earthquakes.Senior seismologist Jonathan Griffin said the quake was picked up by seismometers across the country."[We picked] this one up on instruments in Darwin and Canberra and Charters Towers and places like that," Dr Griffin said.He said an earthquake of that magnitude was a reasonably "decent-sized event"."Getting up towards magnitude-5 is around where you might start to see some damage if it's very close to buildings and things that aren't super well constructed," he said.History of quakes in regionIt is the biggest recorded earthquake in WA this year. Last year, a magnitude-4.7 quake was detected in Wyalkatchem in July, and a magnitude-4.7 quake was recorded offshore in August.In April, there was a 5.5-magnitude earthquake recorded in remote South Australia near the Northern Territory border.Jonathan Griffin says the quake was shallow at a depth of about 5 kilometres. (Supplied: Geoscience Australia)In 2010, a magnitude-5 earthquake hit Kalgoorlie-Boulder, the closest regional city to Cocklebiddy.At the time, it was the biggest earthquake recorded in the region, and it severely damaged several buildings and led to the evacuation of Kalgoorlie's Super Pit gold mine.Dr Griffin said Australia experienced on average one magnitude-5 earthquake every year, and about 100 with a magnitude of 3."Magnitude-5 is about 30 times larger than a magnitude-4, in terms of the energy released," he said.