Mystery earthquake a year after major shake
ALMOST a year after the 5.8 magnitude earthquake to the north of Hayman Island seismic activity continues of the Whitsunday Coast with a 2.8 magnitude aftershock on Wednesday morning.
Geoscience Australia recorded the aftershock at 9:43am on August 2.
"It is almost a one year anniversary earthquake,” said Geoscience Australia duty seismologist Steven Tatham.
"It fits in well as an aftershock to the main event from last year.
"The aftershock sequence is slowing down. We probably had close to 40 and it has dropped down to about 10 since the start of the year.”
There was no reason for people to be concerned as it was normal behaviour of the earth after a moderate earthquake.
He said there has been 55 earthquakes have been recorded in the area in the past twelve month with the 5.8 magnitude event on August 18, 2016 being the largest earthquakes for decades.
"The epicentre is off the coast,” Mr Tatham said. "There would be movement in a pre-existing fault but not a lot is known about the area.
"Prior to the large event one would say it is seismically quiet in the area.”
He said the problem with Australian earthquakes was that they were not very well understood and difficult to predict. They were exceedingly good at occurring when least expected and in the earth had been moderately active.
Australia's nearest plate boundaries, which are areas that typically experience earthquakes, are some distance away to the north in South East Asia and Papua New Guinea and to the east in New Zealand, Samoa and Fiji.
"We are not on a plate boundary and the activity is not very well understood,” Mr Tatham said.
He said the date from the earthquakes would help scientists understand more about the seismic behaviour.
Mr Tatham said Geoscience Australia had no 'felt-reports'come in in relation to the event.