"I'm in a solid brick house and I woke up to the bed rocking," the author and former Katherine Town councillor said.

"There was shaking for at least 20 seconds, I looked over at the clock which said 4am and I thought 'holy cow '."

The 7.3 magnitude earthquake's epicentre was northwest of Darwin in the Banda Sea off Timor Leste at 3.25am.

It was felt widely in the Territory around 4am on December 30 with more than 2000 "felt" reports recorded by Geosciences Australia from as far as Alice Springs in the Territory, the middle of Queensland and the top end of Western Australia.

Ms Toni Tapp Coutts said she was one of many people shaken awake by the tremors.

"I definitely thought that it was an earth tremor because we do get a lot, I was just hoping it was way out to sea and couldn't create a tsunami," she said.

"That was my first thought because it's been so many years since the Boxing Day one (2004 Indian Ocean earthquake and tsunami).

"My daughter lives in an upstairs house and she said the doors were shaking and floors rattling. It's a bit of disbelief but we do have them in the top end and know what they are."

Member for Katherine, Jo Hersey said it was strong in Darwin where she was staying overnight.

"It certainly woke me up, it was definitely shaking the fan and the building," she said.

"I've felt tremors in Katherine before but this was probably the strongest."

Katherine resident Jo-La Burks said she initially mistook the aftershocks.

"I grew up in California so I was very used to what we call 'aftershocks' but I didn't know the Australia and even the territory could get them. I just wrote it off to my muscles shaking from sleeping in the wrong position," she said.

"The dogs were barking so I assumed it was the same as every morning when they were barking at another dog walking past.

"Once I properly woke up I worked out my half sleep logic was wrong."

Chief Minister Michael Gunner posted on his Facebook account about the quake,

"About 4am this morning, Darwin felt the tremble of an earthquake off the Barat Daya Islands in Indonesia," his account said.

"It was certainly one of the biggest we've experienced in the Territory in a while."