About Matanuska Glacier

Experience Alaska's Matanuska Glacier with self-guided access or a guided tour with gear and visits to ice caves and other glacier features.


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Kids investigate sticky, silt clay at Matanuska Glacier in Alaska

The Matanuska Glacier is a large ice flow, 27 miles long and 4 miles wide at the terminus, averaging approximately 2 miles in width. This glacier is a valley glacier; it exists on a valley floor. The majority of glaciers in Alaska today are smaller alpine glaciers which hang off mountain slopes.

The Matanuska is an active glacier which flows at one foot per day in the summer time. It takes approximately 600 years for the ice to form up-glacier and advance to the terminus. The ice of an active glacier always moves forward due to gravity; like water in a river, the ice will flow down the valley. When ice melts at a higher rate than snow accumulates, the glacier terminus 'recedes'. (The term 'receding' does not refer to the ice actually traveling back up the valley.)

A frequently asked question concerns the cause of the blue ice. The density of glacier ice allows the entire spectrum of light to be absorbed with the exception of the blue light which is reflected and can, therefore, be seen by your eye.

Glacier Terminology:

Moraine: Debris (including large boulders, gravel, and sand) that has been deposited by the glacier in various ways.

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1) a build-up of debris between the sides of the glacier and the bases of surrounding mountains from rock slides off the mountain
slopes and




Basal Ice: The debris-rich ice layer at the bottom of the glacier. This ice is easily visible in several places at the terminus. Most sediment comprising the moraines is first transported in the basal ice.



Debris Flow: A small-scale avalanche of rock, debris, and water.

Moulin: A wide vertical shaft connecting the ice surface to the glacial conduit system. Moulins are created by meltwater and can be hundreds of feet deep.



Read more about why we host the Best Alaska Glacier Tours and booking a Matanuska Glacier Hike.