ice worm FACTS

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Alaska Science Forum

April 18, 1980

 

Ice Worm Habitats

Article #391

 

by T. Neil Davis

 

This column is provided as a public service by the Geophysical

Institute, University of Alaska Fairbanks, in cooperation with the

UAF research community. T. Neil Davis is a seismologist at the

institute.

 

 

Recently I was surprised to learn that ice worms are found

occasionally in glaciers of the Alaska Range. Ice worms are numerous

in the warmer glaciers of southeastern Alaska, British Columbia and

Washington State, but they cannot tolerate temperatures much below

zero.

 

Real ice worms--not the spaghetti and ink concoctions of Klondike

poet Robert Service--live in pools of water and crawl around between

ice crystals near the glacier surface. When I expressed amazement

that ice worms could exist in the comparatively cool glaciers of the

Alaska Range, glacier expert Larry Mayo of the United States

Geological Survey stated that the glaciers there are not necessarily

all that cold.

 

Even though temperatures in the mountains are subfreezing many months

of the year, glaciologist Mayo points out that the Alaska Range

glaciers do contain water in liquid form the year around. From time

to time, crevasses become water-filled. Also, channels cut in the

glacier ice by running water sometimes get blocked up and then fill

with water.

 

In winter the water near the edges of these bodies freezes into ice

rinds that may be several tens of centimeters thick. Even so, if a

pool of water is big enough, its center remains unfrozen, proving

that the temperature at depth can remain above freezing.

 

Ice worms have been observed to move around in the ice at depths near

two meters (six feet). Even in the Alaska Range, the glacier ice at

that depth obviously can remain near freezing and so can provide at

least a marginal ice worm habitat. But life there can't be easy.