The Bureau of Meteorology (BOM) says there is no risk of a tsunami to Australia after people across the north of the country were awoken by a magnitude-7.6 earthquake in waters off Indonesia overnight.
At 3:17am ACST on Tuesday, the undersea earthquake struck near the Tanimbar Islands, about 600 kilometres north of Darwin.
Local authorities in the Tanimbar Islands said 15 houses and two school buildings were damaged, with one resident suffering injuries.
So far there have been no reports of damage in Australia.
The BOM said there was no threat of a tsunami to the Australian mainland, islands or territories from the quake.
Geoscience Australia (GA) also received reports of people feeling it in parts of Timor-Leste and Indonesia.
Seismologist with GA, Tanja Pejic, told ABC Radio Darwin the earthquake had a preliminary magnitude estimate of 7.6 and struck 90 kilometres under the Earth's surface.
She said the earthquake was the largest in the area since 2010, with 2,600 reports so far from people who had felt it across the NT and Western Australia.
"Kununurra, Darwin, Tennant Creek all the way to Nhulunbuy [people] were reporting light to moderate shaking," she said
She said it was "quite likely" more aftershocks would occur.
"Certainly we have recorded one so far at a magnitude-5.4," Ms Pejic said.
"So, much smaller. I'm not sure people would have felt that one."
In the event of an earthquake, Ms Pejic said people should stay where they are are and "drop, cover and hold".
This involves dropping to all-fours, seeking shelter under a sturdy table or next to an internal wall, covering your head and neck with one hand and holding onto the table or wall with the other.
Immediately following the tremor, social media lit up with reports of users being woken by shaking, many saying it was the strongest quake they had felt in the territory.
One person said they had felt shaking in Weipa, on Cape York in Queensland.
Pop star Vassy, who hails from the territory, tweeted she "ran out of the house in the middle of the night" as the shaking started.
"It was rather scary. Woke us up in the middle of the night."
Olympian and former federal senator Nova Peris tweeted that "the entire house just shook like crazy and pictures fell off the walls".
Chief Minister Natasha Fyles urged territorians to be alert for aftershocks.
"[I] suspect a few of us are going to need a coffee or four to get going later this morning after that shock," she said on social media.
NT Minister for Business, Paul Kirby, said he was woken up by "the whole house rattling".
"[It was] certainly the biggest and longest earthquake that I can remember in the 20-odd years I've been here," he said.
"I haven't heard any reports of damage which is absolutely fantastic."
Darwin residents share 'crazy' quake stories
After the early morning wake-up call, cafes were full of residents sharing their experiences of the earthquake.
For Darwin local Ann Gibb, despite living in a town used to the occasional tremor, the quake was the worst she has ever experienced.
"[I] woke up, grabbed the dog, went downstairs and listened to everything shake – car alarms going off, dogs going off," she said.
"The whole house was shaking, everything was shaking."
Darwin resident Kayla Spicer said she woke up in a fright.
"It definitely felt like a stronger sort of earthquake than what we usually experience, and I got up and I was a bit scared by it, but it didn't last too long," she said.
Travellers Kim and Steve Badham had just arrived in the NT capital from Newcastle, NSW, when they experienced the tremors from the thirteenth floor of their city hotel.
"It was crazy, we were shaking back and forth, there was a lot of movement in the building," Ms Badham said.
Her husband Steve said "being on the thirteenth floor was a bit ominous".
"We got up and had a look and everyone was looking over their balconies yelling, 'what's going on, what's going on?'," he said.
"And we said, 'it's probably an earthquake'."
The pair had also lived through the earthquake which rocked Newcastle in 1989, claiming 13 lives.
