----------------------------------------------------------

Fed by four alpine glaciers, Fox Glacier falls 2,600 m (8,500 ft) on its 13 km journey from the Southern Alps down to the coast, with it having the distinction of being one of the few glaciers to end among lush rainforest only 300 metres (980 ft) above sea level.

----------------------------------------------------------

----------------------------------------------------------

Although retreating throughout most of the last 100 years, it has been advancing since 1985. In 2006 the average rate of advance was about a metre a week. In January 2009, the terminal face of the glacier was still advancing and had vertical or overhanging faces which were continually collapsing.

----------------------------------------------------------

----------------------------------------------------------

The outflow of the glacier forms the Fox River. During the last ice age, its ice reached beyond the present coastline, and the glacier left behind many moraines during its retreat. Lake Matheson formed as a kettle lake within one of these.

----------------------------------------------------------

----------------------------------------------------------

The glacier is currently 12 km (7.5 mi) long and terminates 19 km (12 mi) from the Tasman Sea. Fed by a 20-square-kilometre (7.7 sq mi) large snowfield at high altitude, it exhibits a cyclic pattern of advance and retreat, driven by differences between the volume of meltwater at the foot of the glacier and volume of snowfall feeding the neve.

----------------------------------------------------------

----------------------------------------------------------

Having retreated several kilometres between the 1940s and 1980s, the glacier entered an advancing phase in 1984 and at times has advanced at the phenomenal (by glacial standards) rate of 70 cm a day. The flow rate is about 10 times that of typical glaciers. Over the longer term, the glacier has retreated since the last ice age, and it is believed that it extended into the sea some 10,000 to 15,000 years ago.

----------------------------------------------------------