Fox Glacier facts: size, retreat and what is changing

Fox Glacier / Te Moeka o Tuawe is the name of both the glacier and the nearby village.⁵ Glacier Country, the regional tourism group, says it is fed by four alpine glaciers, is longer and faster moving than the Franz Josef Glacier, and has a terminal face five kilometres from the village.¹ The same body calls both glaciers the most accessible rivers of ice in the world, plunging through rainforest almost to sea level.⁶

People often ask how big is Fox Glacier, and the honest answer is that the official pages used here give distances, not one length or area, so this page does not quote a total. What they do give is useful. Franz Josef Glacier, for comparison, is six kilometres from the centre of its own village and descends from the tops of the Southern Alps into rainforest close to sea level.⁷

The ice moves. A helicopter operator that flies both glaciers says the Fox sits unusually close to both an ocean and a rain forest, and that its ice flows at up to 3 metres per day in places.⁸ That speed is one reason ice features come and go so quickly, and why a guide who walked a route yesterday may need to cut a new one today.

Since the 1970s the national science agency NIWA, now part of Earth Sciences New Zealand, has flown over the Southern Alps each year for its end of summer snowline survey.¹² The 2023 flight was the 46th, a collaboration between NIWA, Victoria University of Wellington and the Department of Conservation, and it photographed over 50 Southern Alps glaciers.¹³ Some of the photographs are used to build 3D models that track changes in ice volume.²⁶

So is Fox Glacier retreating? The scientists say yes. Professor Andrew Mackintosh said in 2023 that iconic glaciers such as Fox and Franz Josef have retreated markedly, and that the scale of retreat is confronting, even to a glaciologist.² NIWA scientist Andrew Lorrey added that the snowline has been rising, and that in recent years the rise is accelerating.²⁷

The picture is not a straight line downward every year. A later release said that half a century after the first aerial survey, late snow and a variable summer gave a temporary reprieve from rapid ice loss.¹⁴ Dr Lorrey called it a stay of execution and not a reversal in the long-term decline of ice coverage.¹⁵ Earth Sciences NZ adds that every year in the past decade was among the warmest.²⁸

Fox Glacier Guiding says the glacier is there all year because snow falls on its top, in an area known as the Neve, throughout the year and feeds the river of ice.²⁵ The operator guarantees that ice is present, but not any specific ice feature, since features come and go very quickly as the glacier moves while new ones form constantly.⁴ That is the practical meaning of retreat for a visitor: the ice is real, the details are never fixed.

Dr Lorrey said tourism operators are having to penetrate further and further into the mountains to reach New Zealand glaciers.⁴⁰ On Fox Glacier that is one reason a helicopter is the standard way onto the ice. Guiding itself has a long history here: it came alive in 1928, when the Fox Hotel first offered guided trips onto the glacier,¹⁰ and Glacier Helicopters says it pioneered snow landings in New Zealand in 1970.¹¹

On a heli hike, weather permitting, ice time is up to 3 hours, and the operator gives no guarantee that specific features will be seen.²³ The terminal face is far down the valley and out of reach on foot, so a flight is the only way to be standing on the ice itself. Come with the idea of seeing a glacier at work, not a monument, and the retreat becomes part of the story.