A 4.3-magnitude earthquake has struck off the Pilbara coast of Western Australia, less than 48 hours after a severe tropical cyclone swept through the region.

Key points: Locals in the Pilbara region of Western Australia are still mopping up damage caused by Ex-Tropical Cyclone Damien

Locals in the Pilbara region of Western Australia are still mopping up damage caused by Ex-Tropical Cyclone Damien Amid this, a 4.3 magnitude earthquake struck off the coast near Onslow yesterday evening

Amid this, a 4.3 magnitude earthquake struck off the coast near Onslow yesterday evening One benefit of the cyclone was that it brought much-needed rain to the previously parched region

Geoscience Australia described it as a "pretty large" earthquake, which struck about 20 kilometres north east of Onslow at 5.24pm local time yesterday.

"We had people certainly feel shaking, seeing their lights shaking and things like that, and swaying, but there are no reports of damage from the reports that we've seen," seismologist Eddie Leask, from Geoscience Australia, said.

He said residents should prepare for the possibility of aftershocks, potentially even larger than the original event.

Residents of Onslow are being warned to brace for aftershocks following the earthquake. ( ABC Pilbara: Susan Standen )

"It very likely is the honest truth. We do, for these events, get aftershocks regularly," Mr Leask said.

"They might be small ones that are too small for us to pick up on our censors.

"It is even possible that we will get a shock after that is larger than this one.

"That does happen in times and some places — just be aware that it could happen again."

Residents reported feeling the earthquake in Onslow, and even as far away as Karratha, where residents are still mopping up, after Tropical Cyclone Damien caused widespread damage throughout Saturday.

The severe wind gusts from TC Damien caused widespread damage across Karratha and surrounding towns. ( ABC Pilbara: Susan Standen )

TC Damien mop up will take weeks, months

Schools remain closed, some houses and businesses remain without power, and in Roebourne residents continue to experience difficulties with their mobile phone coverage.

Telstra said its crews were working to restore the mobile network, where six sites were impacted when power outages caused the loss of transmission.

But the cyclonic event was not all bad news, with many celebrating the biggest deluge of rain in the parched environment in a decade.

The Millstream Chichester and Karijini National Parks will be closed for a week because of debris and damage, particularly to roads, with up to 250 millimetres of rain received.

But the department's Pilbara operations manager, Geoffrey Passmore, said it very welcome.

"There is no doubt about it, we've been going about two or three years without seeing the Fortescue [River] in flood, so I guess with a cyclone of that proportion you have to take a bit of pain with the wind," he said.

"But we accept the rain with open arms because it's really refreshed the area.

"The beautiful waterfalls we have and of course, the waterholes that we have seen dry up to absolutely nothing will now be full again."

The Millstream Chichester and Karijini national parks will be closed for a week after Tropical Cyclone Damien brought up to 250mm of much-needed rain to the parched Pilbara environment. ( Supplied: Parks and Wildlife Service )

Parched region celebrates deluge

The downpour also topped up Karratha's critically-low water supply, the Harding Dam, which had to be shut off last year after levels dipped below 16 per cent.

Sharon Broad from the Water Corporation said the dam was now close to full capacity and could overflow in coming days.

"We can see that it's filled right up and is only one metre below the full supply level," she said.

"That means we've got enough water in there now to supply the west Pilbara water scheme for about 18 months."

The system continues to track inland, bringing much-needed rain to drought-stricken properties.

Ex-Tropical Cyclone Damien continued to track inland into the Southern rangelands yesterday and with it the low brought some much-needed rain to drought-stricken properties in its path.

Out at Ned's Creek, about 210 kilometres north east of Meekatharra, more than 74 millimetres has fallen since the system passed over their property.

Raelene Hall said it was a welcome relief, after just experiencing their driest season on record since 1946, recording less than 40 millimetres for the year.

"We couldn't have asked for anything better, hopefully it's spread out across the place but it's certainly going to make a big difference," she said.

"If some of this rain gone further out it will certainly get a bit of feed growing and brighten things up.

"If the weather gods are kind to us and we got a bit more in another month, we'd certainly be smiling from ear to ear."

Nearby Murchison station, Mingah Springs, recorded 206mm with reports of flooding and possible stock losses.

There were some other winners from cyclone rainfall in the Gascoyne at Milgun Station with 165mm, Three Rivers with 153 mm, Mount Vernon with 139mm, Doolgunna with 122mm and Mount Clere with 58mm.

The Beasley River in north Western Australia has broken its banks for the first time since March, 2008. ( Supplied: Robin Pensini )

Meanwhile in the West Pilbara, many of the rivers and creeks topped up by Damien are flowing more than they have in years.

The Robe River near Pannawonica is said to have reached its highest level in more than a decade, and the Beasley River near Paraburdoo broke its banks for the first time since March 2008.

An army of volunteers

The cyclone has brought out the very best in the community, with many people and businesses volunteering to help residents clear debris, to help support the SES volunteers.

Karratha resident Nick Hall has helped to form a small 'army' of volunteers to help residents clean up after Tropical Cyclone Damien. ( ABC Pilbara: Karen Michelmore )

Resident Nick Hall helped form a small army of around 30 residents and businesses and were working to respond to almost 100 requests for help through the group's Facebook group Karratha Community Cyclone Preparation Help.

Trees were felled in Karratha by ex-Tropical Cyclone Damien. ( ABC Pilbara: Susan Standen )

They have been pulling trees out of pools, off fences, putting tarpaulin on damaged roofs, and cutting up trees.

"I started up the application form Sunday morning so people could report damages, and so far we've had about 98 reports logged," Mr Hall said.

"I've completed about 20 odd jobs and then we've had so many other people where I've been palming off jobs and they've been going out to do them.

"Before the end of the week we will have hit over 100 jobs completed."

Drone footage shows trees felled by Tropical Cyclone Damien in Karratha. ( ABC Pilbara: Susan Standen )

Disaster takes emotional toll

The clean up from the system is likely to take months and recovery from the emotional toll may take longer.

Paolo Gambi lost his roof in the coastal town of Point Samson and said the experience was haunting.

Paolo Gambi lost the roof to his Point Samson house during Tropical Cyclone Damien, which he described as a "haunting" experience. ( ABC Pilbara: Susan Standen )

"The whole experience was just absolutely and totally unnerving," Mr Gambi said.

"It was just relentless … between eight to 10 hours of non-stop wind. At least in Karratha they got a bit of the eye.

"The last day or so has been quite emotional … just that absolute helplessness that you felt — standing on the second story of the house and feeling it shake around you, watching the water coming in and knowing in your heart you weren't able to do anything about it."

The roof peeled off after about six hours of pummelling, and he sought shelter with his neighbour.