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Canyons, lakes and mountains have been revealed in the most detailed maps ever made of the hidden world beneath the polar regions.

Surveys of the Antarctic and Arctic have revealed features buried under the ice including a 'mega canyon' in Greenland - bigger even than the Grand Canyon in the US.

And data from surveys of the regions has revealed the extent to which Arctic sea ice is gradually decreasing and how long it might take to disappear.

The most detailed maps ever made of the land beneath the polar ice caps in the Arctic and Antarctic have been revealed. Using various techniques researchers were able to show the elevation of bedrock beneath the ice, highlighting amazing land features (shown)

The unseen land under the ice was detailed in the new edition of the Times Comprehensive Atlas of the World.

While previous maps of the polar regions showed them as mostly near-blank whiteness, the latest data has allowed the appearance of the land under the ice to be revealed.

And the maps show the dramatic decline in Arctic sea ice in recent decades as the region is affected by rising global temperatures

Dr Peter Fretwell of the British Antarctic Survey, the joint lead author on compiling the Antarctic dataset, told MailOnline that if there was no ice at the poles the land would look almost normal.

'If the ice was taken away we would have continental features like mountains and canyons, which we don't expect from regions like Antarctica,' he says. 

The data for the maps was mainly collected using a technique known as radio-echo sounding.

This involved flying a plane over areas of interest, firing radio waves at the ground below and measuring how much they were reflected.

And the researchers also used seismic and gravity-wave data to compile the maps.

The sub-ice maps use bedrock data to show physical features such as the Antarctic's Gamburtsev Subglacial Mountains, which are as large as the Alps but completely covered in ice.

In the Antarctic, the map also shows huge trenches buried under glaciers, including the Bentley Subglacial Trench, which reaches a depth of 8,188ft (2,496 metres), and the location of Lake Vostok, lying close to 2.5 miles (4km) under the ice sheet.

The Astrolabe Trench, which contains the thickest ice in the world, is also featured on the map.

At the other end of the world, the map shows Greenland's 'mega canyon', which is more than 470 miles (750km) long and 2,600ft (800 metres) deep, running north to south under the ice sheet.

By comparison the Grand Canyon in Arizona is 277 miles (446km) long and 6,000ft (1,800 metres) deep.

Greenland's canyon - which was discovered in 2013 and is thought to be older than the ice sheet that covers it - is unnamed, although 'Greenland's Grand Canyon' or 'Grand Canyon of Greenland' have been proposed.

The incredible features appear in the new edition of the Times Comprehensive Atlas of the World. Included on the maps is a mega canyon under Greenland. It is almost twice as long and more than twice as deep as the Grand Canyon in the US

Greenland's 'mega canyon', which is more than 470 miles (750km) long and 2,600ft (800 metres) deep, running north to south under the ice sheet, is shown here in an illustration from previous data. By comparison the Grand Canyon in Arizona is 277 miles (446km) long and 6,000ft (1,800 metres) deep

The data for the maps was mainly collected using a technique known as radio-echo sounding. This involved flying a specialised plane (shown) over areas of interests, firing radio waves at the ground below and measuring how much they were reflected to reveal the land hidden under the ice

'It's very important to know how much ice there is and what the topography of the bed looks like, as this is one of the main controls on how quickly ice sheets melt with climate change,' said Dr Fretwell.

He said the data in the survey of the Antarctic bedrock was a key component in scientific models that tried to predict future sea level rises.

'As the world warms with increasing greenhouse gas emissions Antarctic ice will start to melt and cause global sea levels to rise, but the speed and amount of sea level rise is very dependent upon the bed-topography under the ice sheet,' he continued.

The new edition of the Times Comprehensive Atlas of the World also has a map which includes long-term trends in Arctic sea ice cover, showing the average summer sea ice extent from 1981 to 2010, as well as the record low minimum cover in 2012.

It also shows the minimum extent of the ice last year, 18 per cent lower than the 30-year average, using data sourced from the National Snow and Ice Data Centre in the US which tracks polar ice cover.

The sub-ice maps used bedrock data to show physical features such as the Antarctic's Gamburtsev Subglacial Mountains (middle of image), which are as large as the Alps but completely covered in ice

In addition to radio-echo sounding (shown) the researchers also measured seismic and gravity-wave data to compile the detailed maps. Dr Fretwell told MailOnline there were still one or two holes in the data with regards to Antarctica, and there may be even more features hidden underground

Arctic sea ice melts each summer, reaching its lowest extent in September, and the changes to the sea ice cover are seen by scientists as a sensitive indicator of the warming climate. 

Dr Walt Meier, research scientist at the Cryosphere Science Branch, Nasa Goddard Space Flight Centre in the US, said: 'End of summer sea ice extent averages 40 per cent less than it used to be in the early 1980s.

'The ice is also substantially thinner, about half the thickness on average than during the 1980s. 

'The loss of sea ice results in more energy being absorbed in the Arctic, contributing to amplified warming compared to the rest of the globe.'

The previous edition of the Times Atlas, published in 2011, was hit by controversy amid claims by the publishers that 15 per cent of Greenland's ice had melted in little over a decade, an assertion they were forced to admit was 'incorrect'.

A reworked map of Greenland also had to be produced after scientists said numerous glaciers could be found where the atlas showed ice-free conditions and the emergence of new land.

The maps also show the extend to which sea ice is retreating. Arctic sea ice melts each summer, reaching its lowest extent in September, and the changes to the sea ice cover are seen by scientists as a sensitive indicator of the warming climate

While previous maps of the polar regions (pictured) showed them as mostly near-blank whiteness, the latest data has allowed the appearance of the land under the ice to be revealed. And the maps show the dramatic decline in Arctic sea ice in recent decades as the region is affected by rising global temperatures