A rare “persistent lake” of lava has been found at the summit of Mount Michael, a snow-capped volcano in the South Sandwich Islands.
Despite their popular image, volcanoes are rarely topped by an endlessly-bubbling lake of lava — Mount Michael is one of only eight with a persistent lava lake.
British researchers detected evidence of the lake, which reaches temperatures of up to 1,812–2,334°F (989–1,279°C), using high-resolution satellite data.
The lava lake was detected by University College London geographer Danielle Gray along with Alex Burton-Johnson and Peter Fretwell of the British Antarctic Survey.
The bubbling lake of molten rock lies atop Mount Michael on the remote and uninhabited Saunders Island, which is located in the South Atlantic Ocean, around 1,000 miles (1,610 kilometres) north of the Weddell Sea’s eastern edge.
From their analysis of satellite data, experts have calculated that the lake of molten lava is around 295–705 feet (90-215 metres) in diameter.
In contrast to its snowy surroundings, the molten lava atop the mountain has been estimated to be roiling away at an extreme 1,812–2,334°F (989–1,279°C) during the period the researchers were studying it.
‘We are delighted to have discovered such a remarkable geological feature in the British Overseas Territory,’ said paper author and geologist Alex Burton-Johnson of the British Antarctic Survey.
‘Identifying the lava lake has improved our understanding of the volcanic activity and hazard on this remote island, and tells us more about these rare features.’
‘Finally, it has helped us develop techniques to monitor volcanoes from space.’
While popular culture would have every volcano topped by an ever-lasting lake of bubbling lava, the truth is that such features are incredibly rare.
Of the 1,500 active volcanoes currently known on Earth, only seven had previously been known to have persistent lava lakes, Dr Burton-Johnson told Live Science.
While temporary pools and lakes often form when volcanoes erupt, these typically dry up into solid rock within days or weeks
The rare bodies that are able to stay molten are kept at a high enough temperature by heat from such volcanic gases as carbon dioxide, sulphur dioxide and steam, Dr Burton-Johnson explained.
The first hints that Mount Michael might have a lava lake came from a heat anomaly detected on Saunders Island in low-resolution satellite data collected in 2001.
It took higher resolution satellite data — taken from 2003–2018 — and the researchers’ advanced analysis techniques to confirm the lake’s existence.
While the images are conclusive, researchers are not sure how far below the rim of the 2641 feet (805 metre) -high volcano’s crater the lava lake presently lies.
‘Mount Michael is a volcano on a remote island in the Southern Ocean,’ said Ms Gray.
‘It is extremely difficult to access, and without high-resolution satellite imagery it would have been very challenging to learn more about this amazing geological feature.’
Saunders Island belongs to the remote volcanic chain known as the South Sandwich Islands which, along with the nearby island of South Georgia, have been designated a British Overseas Territory.
In fact, the island’s secluded location has meant that few researchers have ever even been to Mount Michael.
‘It has been visited at the bottom very rarely, and no one has ever got to the summit,’ Burton-Johnson told Live Science.
With this initial study complete, Dr Burton-Johnson said that the next step would be aerial photographs of the lava lake to be taken by an aircraft or drone flying over the volcanic crater — but that such might take years to arrange.
‘The problem is that the South Sandwich Islands are so incredibly remote, there is very little ship traffic that goes past there,’ he told Live Science.
‘So there are not a huge amount of opportunities for research vessels in that area.’