Milford Sound

There are three ways to Milford, a fingerlike indentation in the coast of Fiordland National Park – by road, by plane and on foot, each giving a different and equally memorable perspective. At the end lie the deep waters of Milford Sound from which rises the sheer glaciated slab of Mitre Peak to lend the fiord its special charm. Much photographed, the pinnacle promises to be a perfect cone, an illusion dispelled when it is seen from the sea as simply one peak in a chain.

From hanging valleys where once subsidiary glaciers joined the departed main ice flow, tall falls now drop their mountain-fresh waters cleanly into the sea. The mingling of mountain, bush and fiord is broken only by a smattering of fishing boats and a scattering of buildings at the head of the Sound. The region’s annual rainfall ranks with the country’s highest, a phenomenal 6,240 mm.

The Maori knew Milford Sound as Piopiotahi („the single thrush“) as the fabled creator-discoverer Maui is said to have had with him a large bird brought from Hawaiki. When Maui was crushed to death between the thighs of Hine-nui-te-po, the sorrowful bird, who witnessed the tragedy, fled here to give its lonely name to the secluded Sound. The origin of the Pakeha named is uncertain.
Today, the large Fiordland crested penguin, with its distinctive yellow crest, and the small blue penguin, may both be seen. Periodically dolphins accompany the launches as they ply the Sound.

A fiord is formed where the sea enters a deeply excavated glacial trough after the melting-away of the ice. One of the finest of the New Zealand fiords is Milford Sound, enclosed by walls that rise 1,200 metres vertically from the sea. Its most striking geological feature is the steep-walled, flat-floored depression that occupies the middle third of the fiord. The Entrance Sill ceases at a depth of 120 metres, to the west of Stirling Falls at a point where steep rock spurs narrow the Sound. To the east the Sound broadens but at the same time plunges steeply to a depth of 290 metres, so that the water inside the fiord is very much deeper than it is at its entrance.

The phenomenon has been interpreted as a rock-basin cut from the bed of an existing glacial valley during a later phase of glacial advance. The Entrance Sill, at the seaward end of the basin, is a rock barrier and not terminal moraine from the younger glacier – a theory reinforced by the hard rock spurs to the north and south of the Sill. The thickness of the ice that excavated the basin is shown by the height of the subvertical cliffs, practically devoid of vegetation, that rise from below sea level to truncate the U-shaped profiles of older glacier valleys. These „hanging valleys“ are particularly noticeable in the area. Where once smaller glaciers served as tributaries to the main iceflow, streams now run and enter the principal valley as waterfalls, e.g. the Bowen, Stirling and Sutherland Falls. Sinbad Gully is another hanging valley, but this can escape notice as its mouth is at sea level. The Jervois Glacier on Mt Elliott is the surviving fragment of the great glacier that formed both the Arthur Valley and Milford Sound.