NEWS AND NOTES ABOUT SCIENCE
BURNING LAVA LAKE CONCEALED BY A VOLCANO’S GLACIAL ICE
While Earth’s surface is peppered with volcanoes, lava lakes appear to be vanishingly rare. Popular imagery of volcanoes may imply that these crowning caldrons of liquid fire are common, but there were thought to be only seven contemporary volcanoes on Earth with persistent lava lakes that have been seen to stick around beyond a single eruptive outburst.
Now, using 30 years of satellite observations, a group of scientists from University College London and the British Antarctic Survey has added an eighth volcano to that list: Mount Michael, a 3,250foot high stratovolcano on Saunders Island, a frigid outpost 1,000 miles from Antarctica, the nearest major land mass.
Monitoring this molten reservoir may improve our ability to somewhat forecast the potential hazards from other volcanoes containing lava lakes that are closer to human populations, said Jani Radebaugh, an expert in planetary satellites at Brigham Young University who was not involved with the study.
Mount Michael is an active, sputtering volcano largely covered in glacial ice. Its slopes are dangerous, and it has never been summited. It’s also so far from civilization that “it’s almost like it’s on another planet,” said Rosaly Lopes, an expert in planetary and terrestrial volcanology at NASA’s Jet Propulsion Laboratory who was not involved with the study.
That meant that finding it required satellite observations and analyses. Starting in the 1990s and early 2000s, some orbital eyes spotted prolonged thermal anomalies that hinted at a lava lake’s existence, but couldn’t prove it. But improved satellite imagery from the Landsat, Sentinel-2 and the Terra missions and better processing techniques have allowed this lake to be conclusively identified in a report published this month in the Journal of Volcanology and Geothermal Research. Its thermal signature could be seen throughout the observation period, suggesting the lake is probably persistent.
The team collected enough shots of the lake from 2003 to 2018 that clearly showed a crater floor containing a superheated lake 295 to 705 feet across. The lava is also 1,812 to 2,334 degrees Fahrenheit, with the higher end of that range about as hot as lava on Earth seems to get.
This discovery emphasizes the geographic diversity of persistent lava lakes. Others have been found within Ethiopia’s Erta Ale, Antarctica’s Mount Erebus, the Democratic Republic of Congo’s Nyiragongo, Nicaragua’s Masaya, Vanuatu’s Mount Yasur and Ambrym and Hawaii’s Kīlauea.