The Sphinx, a well-known snow patch in the Cairngorms of the Scottish Highlands, has fully melted for what’s thought to be just the eighth time in the last 300 years. “Snow hunter” Iain Cameron reported the finding today.
In recent weeks, visitors found the snow patch had dwindled to the size of a sheet of A4 paper. Historically, it rarely melts entirely, although it has done so more frequently over the last two decades. The BBC cites records that show that The Sphinx also vanished entirely in 1933, 1959, 1996, 2003, 2006, 2017, and 2018.
Before 1933, it’s thought that the last time it disappeared was during the 1700s.
Two types of snow patches exist –- perennials, which endure at least two summers in a row, and seasonals, which melt every summer. The Sphinx, which has now melted five times in the last 18 years, seems to be on the brink on the brink of becoming seasonal.
The disappearing Sphinx: conditions and history
Cameron has studied snow patches in Scotland for 25 years, and written a book on the topic called The Vanishing Ice. He said that The Sphinx is historically the UK’s “most durable” snow patch.
Cameron investigates a snow patch tunnel. Photo: Iain Cameron
Cameron indicates that warmer temperatures from climate change “seemed to be the logical” explanation for the increased melting rate.
“What we are seeing from research are smaller and fewer patches of snow. Less snow is falling now in winter than in the 1980s and even the 1990s,” he said.
A 2020 report commissioned by Cairngorms National Park Authority corroborates Cameron’s claims. Focused on Cairngorm Mountain, the report showed both declining snow cover and fewer snowy days since 1983-84.
It shows that although average monthly precipitation has increased in November, December, and January since 1960, snowpack in the same area has decreased. Since winter 1983-84, maximum snow depth has decreased by about 10 cm, and the overall average has decreased by about 3 cm.
Iain Cameron and Dr. Blair Fyffe at another perennial snow patch, the Observatory Gully patch on Ben Nevis, August 2008. Photo: Mark Atkinson
Long before the National Park’s study, the Scottish Mountaineering Club started monitoring The Sphinx. It lies at the base of Braeriach (the UK’s third-highest mountain at 1,296m) near a climbing route of the same name. The club started noting the snow patch’s status in the 1840s.
In the next week, the Cairngorms National Park forecast shows some chance of rain, but temperatures are still too mild for snow, at around 7˚C, to begin building up the patch again.
Snow patches near Ben Nevis in the Scottish Highlands. Photo: Shutterstock
Why is the snow patch red? ‘Blood’ snow, algae, and melting
The red tinge to the snow, visible behind Cameron in our lead photo from early October, comes from a film of live algae. Sometimes called watermelon snow or blood snow, the effect results from a species of green algae that contains both chlorophyll and carotenoid pigment.
Unlike most algae, it thrives in cold water. When colonies grow on snow, they darken the surface slightly, and the snow melts faster. That means more cold water for the algae and better growing conditions.
Watermelon snow in California. Photo: Paul Wade
John Ross, captain of an 1818 English expedition to the Arctic, made the western world’s first note of the effect. He noticed it while rounding Greenland’s Cape York and named the area “the Crimson Cliffs.”
According to the National Snow and Ice Data Center, snow algae continues to become more common worldwide, exacerbating snowmelt.
