Margerie Glacier is a tidewater glacier in the Glacier Bay National Park and Preserve, Alaska. The 34 km (~21 mi) long and 1.6 km (1 mi) wide glacier is named after Emmanuel de Margerie, who visited the bay in 1913.
A tidewater glacier is a valley glacier that starts on land and, through falling snow, flows out to sea (or rivers and lakes). In the case of Margerie Glacier, it begins on the south slope of Mount Root and flows to Tarr Inlet. When the ice flow enters the water it begins to float. Margerie has a height of 110 m (360 ft), but only 76 m (~249 ft) of that is above the water level. The remaining 34 m (~111 ft) is below water level. Tidal waters can cause ice to break away from tidewater glaciers resulting in icebergs and smaller chunks of floating ice, a process known as ‘calving’.
Margerie Glacier can be reached only by air or water. Boats and cruise ships are able to anchor near to the glacier, offering exceptional views of Margerie to all on board. It is one of the more pristine of the Glacier Bay glaciers and up close, spectators can experience the magnificent sculpture-like quality of the glacier and the jewel-like blue ice. Hours can be lost looking at the endless jagged peaks and distinctive ice formations.
Margerie Glacier is also one of the most active glaciers in the bay and is thought to be stable – that is, not receding. Lucky spectators may witness ‘calving’. The awesome sight of this natural phenomenon is accompanied by an incredible sound as the ice cracks and falls thunderously into the water.