We’ve almost forgotten it, but Wordie wasn’t always a bay: it was once an ice shelf, and its slow disappearance is a textbook example of the powerful phenomenon of glacier collapse at work in Antarctica.
Wordie was a floating ice shelf positioned at the mouth of nine glaciers. It was the union of nine ice tongues: the Hariot, the Sans Nom, the Airy, the Seller, the Fleming, the FIP 1 and 2, the Prospect and the Carlson, at the southernmost point. They came together to form a flat expanse on the sea at the head of Marguerite Bay.
In the 1960s, an American photographer took photos of Wordie aboard a military aircraft that was criss-crossing the Antarctic Peninsula from Chile, for mapping purposes.
Based on 450 now archived images, an American-European research team showed, in the journal Nature Communications last April, that Wordie was then in good health, before his decline.
Around 300 metres thick, it measured 2,200 square kilometers and was the most northerly of the large ice shelves on the western Antarctic Peninsula. Its anchorages were numerous and made up of underwater reliefs.
From the chronological study of its disappearance, it would seem that, under the photographer’s lens in 1966, it had reached its maximum area of extension.
In 1972, the Meadows report pointed out the limits of economic growth and its impact on ecosystems, particularly via greenhouse gases.
Until 1974, wear and tear on the ice platform was limited, but became more pronounced from 1979 onwards.
Between the 1970s and the 1990s, the British Rothera station recorded a 1°C increase in atmospheric temperature. Ocean temperatures rose by 0.3°C between 1960 and 1990.
Following a series of calvings, the platform splits in two, and four years later, the Fleming’s ice barrier is no longer linked to its companions, neither Hariot nor Sans Nom. During this period, the retreat of the ice fronts doubled, and the Carlson began to stand apart before almost disappearing in 1986.
In 1988, the Intergovernmental Panel on Climate Change was established.
A 1991 study points to atmospheric warming as the main cause of Wordie’s disappearance.
In the words of Mads Dømgaard, postdoctoral fellow at the Department of Geosciences and Natural Resource Management, in a release from the University of Copenhagen’s Faculty of Science published this month: “Our findings show that the main factor behind the Wordie collapse was rising sea temperatures, which caused melting beneath the floating ice shelf.”
With the disunity of the nine glaciers at its height, a period of respite set in. Fleming picks up the pace on the water, despite the increased formation of crevasses upstream.
The decade from 1990 to 2000 saw an extension of the platform’s surface. Ocean temperatures stabilize. The bay is filled with stray ice. Former companions pick up the pieces.
In 1995, the first COP on climate was organized.
By 1998, the platform had grown to a modest 700 km2. As for its anchor points, they are not progressing: they continue to thin out and retreat towards the coast.
Between 1966 and 2001, the ice front in the Carlson sector retreated by 6.6 km. In 2002, French President Jacques Chirac declared at the 4th Earth Summit: “Our house is burning and we’re looking the other way.”
A second wave of accelerated retreat shook Wordie between 2000 and 2007. Ice debris melts in the bay. The Fleming platform disappeared in 2000. The Carlson platform came close to total disappearance in 2002. The rest of Wordie hails on all sides, detached from the coast, in an image from 2004.
The Hariot platform was extinguished in 2009, and the Reuters news agency reported the words of the U.S. Interior Secretary under President Barack Obama, Ken Salazar: “The rapid retreat of glaciers in this region demonstrates once again the profound effects that our planet is already experiencing – more rapidly than previously thought – as a result of climate change.”
Also those of glaciologist Jane Ferrigno: “This continuous and often significant retreat of glaciers is a warning signal that changes are underway… and that we need to prepare for them.”
Prospect, FIP 1 and 2 lost their advance to the sea in 2012 and 2014, and Sans Nom in 2023. Today, the site of this massive, slow and powerful melting is called Wordie Bay.
In the University of Copenhagen press release, Anders Anker Bjørk, professor at the Department of Geosciences and Natural Resource Management, explains that the phenomenon is slow, and that: “Based on the findings of studies such as this one, the risk of a very rapid and violent rise in sea level due to melting ice in Antarctica is slightly lower than expected.”
But, in view of the strength of the phenomenon, he points out that “it is more difficult to reverse the trend once it has begun. This is an unambiguous signal that we need to give priority to stopping greenhouse gas emissions now, rather than in the distant future.”
The Wordie story is not only a textbook case for the ongoing study of Antarctic glacier destabilization, but also a symbol of the history of climate policy.