'Like a train': remote earthquake biggest in decades

An earthquake that sounded "like a train" and rattled cupboards was the largest in southwest Tasmania in two decades and felt across the island.

The 4.1-magnitude tremor struck at 6.38am on Thursday near Lake Pedder at a depth of 14km.

More than 120 people reported the earthquake to Geoscience Australia, including in Hobart, in Queenstown on the west coast and in Launceston in the north.

One resident in Burnie posted on social media that it sounded like a train going down the street, another south of Hobart reported glassware rattling in cupboards.

There had been no calls for assistance or damage reported, the state's emergency service said.

Geoscience Australia senior seismologist Hadi Ghasemi said it was the largest quake within a 100km radius of the epicentre in 20 years.

"Tasmania is not high seismicity," he said.

"But this event …. is testament that earthquakes can happen anywhere in Tasmania."

Dr Ghasemi said the largest earthquake documented in Tasmania was a mid-to-high magnitude six in the late 1800s off Flinders Island.

Hydro Tasmania said no damage had been identified to its dams in the region including Edgar Dam, which is undergoing upgrades.

The dam, about 30km from the earthquake, could withstand tremors of up to 6.8 magnitude along the Lake Edgar fault line, the electricity provider said.

"This earthquake was well below that and was not on the fault line," Hydro Tasmania's general manager of assets and infrastructure Jesse Clark said.

"The upgrade will strengthen the dam even further."

Hydro Tasmania said it had extensive seismic monitoring and would continue to inspect and monitor infrastructure over coming days.