Julius von Haast, geologist and explorer, named Franz Josef Glacier in 1863, after Emperor Franz Josef of the Austro-Hungarian Empire.
The Maori name for the glacier is Ka Roimata o Hine Hukatere The Tears of Hine Hukatere, named after the Maori legend of lovers Hine Hukatere and Tuawe. Tuawe fell to his death while exploring Fox Glacier and Hine's tears of grief formed the Franz Josef Glacier.
During the last Ice Age over 13,000 years ago, ice-sheets extended over the lowlands of New Zealand and down to the sea. Temperatures were at least 4 degrees Celsius cooler than at present.
The Franz Josef Glacier is approximately 7000 years old, and a remnant of a much older and larger glacier which originally swept right to the sea. Today it is 12 kilometres long, from the high snowfields of the Southern Alps.
Scenic reserves were established to protect the glaciers and local lakes in 1910. In 1990 2.6 million hectares of South West New Zealand was declared a World Heritage Area. The World Heritage Area protects Fiordland, Mt Aspiring, Westland and Mt Cook National Parks.
Today the terminal face of Franz Josef is just 19 kilometres from the sea and only 5 kilometres from Franz Josef township. The relatively easy access provided by this unique glacier means you can enjoy a guided walk on the glacier, a scenic snow-landing flight or a heli-hike.
Layer after layer of snow is compressed into hard ice in the neve and then the glacier begins to flow down the valley as a river of ice, rocks and stones. The uneven valley floor and steady slow movement causes crevasses and pinnacles to form, creating the unique and ever changing landscape of the glacier.
The vivid blue colour of the glacier ice makes for some stunning photographs and is caused by refraction (bending of light as it passes through the ice crystals).
The speed of glacial ice flow depends on the steepness of the valley, with the Franz Josef Glacier taking about five years for ice to flow from the neve to its terminal and Fox Glacier taking about seven years to reach its current terminal face.
Since the last Ice Age glaciers around the world have generally retreated, but there have been several big advances over those years. Advances are usually caused by extra snow falling in the neve on a short term basis.
Franz Josef's glacier terminal was over Sentinel Rock in the 1890's and at the same location as the present car park as recently as 1920.
Due to strong snowfall in the snowfield at the neve of Franz Josef, it is one of the few glaciers in New Zealand which is still growing, as of 2007. The flow rate is about 10 times faster than that of normal glaciers, resulting in movement of about 70 cm per day when the glacier is advancing.