It was given its name in the 1940s due to the rocks surrounding it on Garbh Choire Mor, a glacial trough carved into the rock.
Records show that in the 20th century it melted on three occasions – 1933, 1959 and in 1996.
So far during the 21st century, it has melted eight times in 24 years.
READ MORE: Northern Lights sightings possible in Scotland this weekend
This year it has melted for the fourth year in a row, which has been attributed to climate change, and it is believed to be the 11th occasion it has melted since the 1700s.
Citizen scientist Iain Cameron, 51, from near Stirling, has monitored it closely for 20 years and believes the ice patch is a “barometer for climate change”.
Mr Cameron visited on Thursday and said the patch measured around 0.5m – and will have melted overnight.
He described it as “like visiting an elderly relative”, having seen it measure between 2m and 50m in previous years.
Mr Cameron said: “It is the 11th time since the 1700s that it has melted.
A sad day today. The Sphinx will melt in the early hours of tomorrow morning, meaning that’s the fourth consecutive year it has done so.
This patch was once considered permanent. It has now melted completely since the 1700s in the following years:
1933
1959
1996
2003
2006
2017… pic.twitter.com/yV5T9yulA4— Iain Cameron (@theiaincameron) October 3, 2024
Citing reasons for the increasing melt, he added: “There have been far fewer western-facing storms from the Atlantic. There’s not as much snow falling in winter. We don’t get as much snow as we used to get, precipitation is mostly rain.”
It has never before melted four years in a row, according to 200 years of data.
The ice patch was initially monitored in the 1840s by the Scottish Mountaineering Club. In 1933 a letter was written to The Times newspaper noting that it had melted for the first time in living memory, by a cohort of mountaineers whose lived experience dated to the mid-1800s.
In 2003 and 2006, it vanished, and it did so again in 2017 and 2018. Scotland was hit by the Beast from the East in 2018 but it did not benefit the Sphinx as it is eastern-facing.
Since 2020, the patch has vanished every year.
Mr Cameron wrote a book about his enthusiasm for snow, The Vanishing Ice, in 2021, and said he initially felt the title was pessimistic – but he now feels it was accurate.
He said the size of the Sphinx depends on factors including summer temperature and winter snowfall.
Mr Cameron said: “The Sphinx is a vestige of the last Ice Age. It is the place in Scotland where glacial regeneration will occur.
“Importantly, we can see that patches of snow which lasted through decades and centuries are dispersing.
“These patches of snow act as barometers for climate change.
“I’m not a scientist or climatologist, I’m just someone who writes about these things.
“It makes me feel sad – I’m used to seeing them survive, it’s like visiting an elderly relative.”
