By Poppy Wilson
The continent of Antarctica was first sighted two hundred years ago, proving the existence of erra Australis Incognita (“Unknown Southern Land”). Coinciding with the anniversary of this significant discovery, scientists have successfully drilled into one of this continent’s most unstable glaciers.
Thwaites Glacier is roughly the size of Britain. Its location is remote and hostile, even for Antarctica’s standards, being 1600km from the nearest research station.
The glacier has lost 54 billion tonnes of ice since the 1980s
Despite long being hailed as one of the world’s “most important” glaciers, Thwaites Glacier is remarkably understudied – the extreme remoteness and hostile environment are key factors in this.
The instability of Thwaites Glacier was highlighted last year when NASA reported finding a massive cavity, roughly the size of Cambridge, growing at the bottom. The hole could have held 14 billion tonnes of ice, most of which is predicted to have melted in only the three years prior to its discovery.
Indeed, since the 1980s it is predicted that the Thwaites Glacier has lost approximately 54 billion tonnes of ice, with the melting rate doubling across the last 30 years. With the glacier already contributing 4% of global sea level rise each year, it’s crucial to determine how this may increase in the future. In a cautionary manner, glaciologists have suitably coined Thwaites as the “doomsday” glacier, as its melting would hike sea levels by over half a metre. For perspective, 40% of the world’s population live within 100km of the coast and significant sea level rise could displace millions. It is precisely for these reasons that the International Thwaites Glacier Collaboration (ITGC) was set up in 2018.
Melting of the Thwaites glacier could cause sea levels to rise by over half a metre
The ITGC is a five-year long joint UK and US project, involving over 100 scientists and costing £38 million. They aim to seek the answers to two key questions: how much could the Thwaites Glacier contribute to sea level rise, and how soon could this materialise? They aim to explicitly examine the stability of the titanic Thwaites Glacier.
In the last couple of weeks, the scientists working as part of the MELT division have successfully drilled into Thwaites Glacier. Using hot water to melt the ice they created a 600-700m long hole through the ice sheet.
The glacier already contributes to 4% of sea level rise
The group then dropped the NASA-funded IceFin robot through this hole to the grounding zone, which is the point at which the base of the ice sheet comes afloat, meeting the ocean water.
IceFin has provided crucial information regarding the interaction between the glacier and the ocean. The robot has proven that warm circumpolar ocean water has reached the front of the Thwaites Glacier and is “set- ting the glacier on fire”. Climate change is responsible for this worrying interaction as shifting wind patterns due to a warming Pacific Ocean are to blame.
Understanding what is happening to the Thwaites Glacier is key for us to accurately predict future sea level rise. Thwaites may not be going anywhere fast – in fact, scientists say it could take over a century to disappear – but we simply cannot choose to ignore this data. Acting now is imperative to mitigate climate change induced sea level rise.
Image: Kimberly Vardeman via Flickr