Mysterious Earthquake Swarm: Australian Town Hit With 33 QUAKES in 30 Days

A TOWN won’t stop shaking having been hit with 50 earthquakes in the last two months.

Norseman, located 720 km east of Perth in western Australia, has had more than 30 quakes this month.

The first quake – of 5.0 magnitude – shook the town on May 28 in the middle of the night. It was soon followed by an even stronger 5.1 magnitude tremor an hour later.

John Fry, works manager at the local government, said he heard a loud rumbling during the middle of night but did not realise it was an earthquake.

He said: “I thought it was just a train coming through.

“The last thing you think of is an earthquake.”

The town residents have had to deal with aftershocks – smaller quakes that follow large earthquakes – ever since.

The tremors have ranged in intensity from 2.7 to 4.2 in magnitude with the exception of a 5.6 quake earlier this month.

In 1985 the town endured five years of aftershocks after an earthquake of 5.6 in magnitude

Hugh Glanville, seismologist at Geoscience Australia, said the phenomenon is a reasonably classic earthquake sequence.

“When a large section of a fault moves quite significantly – that has relieved stress on that part of the fault.

“So the adjacent parts of the fault will move to release the stress that has been transferred to them.”

However, locals are not strangers to seismic activity.

In 1985 the town was hit by an earthquake of 5.6 magnitude triggering years of shakes.

Geoscience Australia senior seismologist Dan Jaksa said of the time: “An aftershock sequence happened for about five years afterwards, there were a number of magnitude fours and threes, and slowly the frequency of those events died away.

“We are actually seeing the same sort of activity now in 2016.”

Mr Jaksa admits there is no way to know yet if the aftershocks will last five years this time around.

The town can expect to be shaking for a couple of months longer.