An underwater robot first sent out four years ago has returned the first high-resolution 3D maps of Antarctic sea ice, providing a better snapshot of the impact of climate change.

Measuring the thickness of Antarctic sea ice has long been a challenge and traditional methods are less than ideal.

Dr Rob Massom, senior research scientist with The Australian Antarctic Division, said to date the job was low-tech and manual.

"We look over the side of icebreakers and we look at the way that the icebreaker overturns the sea ice and we do a visual estimate on the hour every hour," he said.

"We also spend many hours drilling many holes through the ice and that's very labour-intensive."

But not any more, according to a research paper that published the findings of scientists from the UK, USA and Australia.

The report detailed how an underwater robot, or Autonomous Underwater Vehicle, which was sent out to east and west Antarctica in 2010 and 2012 had delivered the first extensive and precise measurements of Antarctic sea ice.

Sorry, this video has expired Antarctic sea ice retreat ( NASA Goddard Space Flight Center )

Co-author Dr Guy Williams from the Institute of Marine and Antarctic Studies said the results found sea ice depths ranged from about one metre to 15 metres.

"We had average flow thickness between 1.5 metres to up to 5 metres, and in some places the thickness was up to 10 metres to a maximum of 15," he said.

Dr Williams was not surprised by the finding, but it was the first time an accurate measurement was available.

"We've previously thought the sea ice was this thick, certainly divers next to the ship have seen very thick ice," he said.

"But really, measuring is believing, this is the first time we've been able to measure it."

Robot allows more accurate gauge of climate change

Ice core researcher Dr Tas van Ommen said sea ice depth was one measure of climate change.

"It's not a simple indicator, but yes it's an indicator because sea ice is controlled by a range of things - winds, temperatures of the atmosphere, temperature of the ocean," he said.

Recently climate changes sceptics had pounced on the growing amounts of sea ice measured from satellites.

Dr Van Ommen said being able to measure thickness will provide a better snapshot of the impact of climate change on the sea ice.

"At the moment we can only take large-scale measurements from space about the spread or extent of sea ice, we can't measure its thickness and that's why this study is so important," he said.

"Allowing us for the first time to get an indication of the thickness of the ice, and understand the processes by which it grows and decays."

Dr Massom agreed.

"We know its expansion and contraction every year, from about 19 or 20 million square kilometres to about four million in summer, but what we haven't had is the thickness of this ice," he said.

Dr Van Ommen said using the data to compare with future studies and satellite measurements will give a much more precise reading of what the sea ice is doing.

"One of the big challenges for our researchers is to take the new technology and find a way to actually combine that with information from satellites and ship based information," he said.