Some Canberrans have been shaken awake a little early this morning by an earth tremor west of the capital.
And while it is unlikely they will be woken again by similar earth tremors, there will almost certainly be aftershocks, seismology professors say.
But professor Brian Kennett, who has been studying and mapping earthquakes in the ACT since 1984, said only those standing directly above the aftershocks would be likely to feel them.
This morning's magnitude 3.7 tremor originated about 40km west of the ACT, halfway between Canberra and Tumut, at 5.09am and could be felt by people up to 46km away, Geoscience Australia has reported.
Geoscience Australia duty seismologist Steve Tatham said the agency has received over 100 reports from people across the region who felt the quake.
"People are reporting shaking, earth noises, windows rattling, describing it like a heavy vehicle rumbling past," he said.
"One fellow from Canberra even reported items shaking off his bedside table."
"[It's] a very exciting event, but certainly nothing to be worried about at this magnitude."
Mr Tatham said there have been four earthquakes in the region over the past decade or so, with the largest tremor measuring 4.2 magnitude in February 1998. While the region has a moderate seismicity, Mr Tatham said most tremors usually occur further north, around Gundaroo.
He said while small aftershocks were possible, they aren't normally observed for such small tremors.
Emergency services said this morning that call centres had received a few calls, but no damage has been reported.
Readers contacting The Canberra Times have reported feeling the quake across the region, as far as Yass in the north, Batlow in the west, Clyde Mountain in the east, and Gordon in the south.
Richard from Gungahlin said he was watching the sunrise from the top of Mount Ainslie with friends when he felt the earth begin moving.
"We felt the trembling of the ledge looking over the edge," he said in an email to The Canberra Times.
"It was a slow vibration but you could definitely feel the ledge shaking. We had no idea what it was and joked about it being an earthquake only to come back home to find out it was one! Quite a surprise."
Robert from Dunlop said he was lying in bed dozing when he felt the tremors.
"It felt like I was lying in the ocean and went over a wave. Very bazar [sic]," Robert emailed in this morning.
"I have felt earth quakes before (very loud one that shook the windows and doors of our house to the point that I thought they were going to fall off or shatter), but this one just felt like I was floating in the sea!"