The mountains, which are thought to form the planet's largest range of peaks, were discovered under Antarctic ice caps
Edinburgh University researchers uncovered almost 100 volcanoes - with the highest almost as tall as Switzerland's 3,970-metre Eiger.
Geologists think the region, which sits two kilometres below ice in west Antarctica, will dwarf east Africa's volcanic ridge, which is rated as the world's densest concentration of volcanoes.
Glacier expert Robert Bingham, who helped author the paper, warned The Guardian the range could have worrying consequences.
'If one of these volcanoes were to erupt it could further destabilise west Antarctica's ice sheets.
'Anything that causes the melting of ice - which an eruption certainly would - is likely to speed up the flow of ice into the sea.
'The big question is: how active are these volcanoes? That is something we need to determine as quickly as possible.'
