Living Among the Cook Inlet’s Shrinking Glaciers

Portage glacier 1974

The Retreating Matanuska

The tremendous Matanuska Glacier is slumping into the ground like an expired prehistoric animal, its once mighty surge punctuated by the fresh black boulders it had accumulated in its steady march, and that after thousands of years, laid once more exposed to the sun. As a child, the Matanuska represented one of my first introductions to earth geography. A field trip consisted of driving through the Matanuska Valley, stopping to examine the thick, black soil that reminded one of the fertile loam used for growing African violets. Our field guide would explain how the glacier had once held the entire valley in its frozen grip, leaving behind the tons of rich earth it had scooped up as it continued on its journey.

The valley had the extraordinary quality of being completely virgin soil. No farm implement had touched it since the last ice age, now marked only with a generous frosting of mountain glaciers. Between the long summer hours of sunlight and the nutrient rich soil, the valley would begin yielding record-breaking 30 kilograms plus cabbages, green beans in excess of twelve centimeters long and bumper crops of giant strawberries, plump potatoes, peas, carrots and other cold weather plants. For early settlers, the glacier had left behind a valuable treasure.

Our educational journey continued into the Chugach, a steep climb with towering mountains on one side, and sheered off cliffs on the other. The cliffs were the path carved by the Matanuska. You could see the rhythm on the walls of the naked cliffs in undulating patterns. Far below was the tumultuous Matanuska River.

The glacier itself, was an education in the transforming earth. You could mark the shrinkage age by the amount of flora that had sprung up around the newly exposed earth. The oldest ring consisted of spindly fir trees and brush that had finally emerged on the exposed landscape. The second layer was newly greening with grasses and tundra moss. The inner layer, next to the glacier, was the black shelf of tumbled boulders recently abandoned by the glacier’s retreat.

At the time, we were told the glacier was retreating at a rate of four centimeters a year. That was forty years ago. Now, the glacier retreats between six to ten centimeters a year. In the summer, the field of black boulders appear greater than the glacier itself.

The Matanuska River is fed from glacier and snow melt. Always turbulent, especially warm summers send it hurtling through its cavernous home, uprooting trees and flooding low-laying banks. The Matanuska can become so vigorous, it will cut new paths through the valley, carving away at the unfortunate inhabitants’ real estate. Its rushing course sends tons of fresh water into the Cook Inlet each year.

A Visit to Portage

Portage Glacier retreat
Photos of the Portage Glacier 3 decades apart (click to enlarge)

Although the Matanuska is one of Alaska’s most rapidly shrinking glaciers, nothing is quite as astonishing as a visit to Portage. Those who remember the Portage glacier of forty years ago will find very little to refresh their memories. The early pioneers saw a glacier that was primarily ice, with very little water surrounding it. The water they saw was interrupted by giant ice bergs floating close to the shore. By the late 1970′s, a definite lake had formed, although it was still punctuated by massive icebergs. The glacier dumping into the lake was still enormous. A visit now will reveal a very large lake, a few lumps of floating ice, and a shrinking glacier marked by its recent land exposure.

While the Portage does have its outlets into the Cook Inlet, much of its shrinkage is marked by evaporation. The first few weeks of spring on the Cook Inlet are usually marked by warm, clear weather. However, as the sun becomes more intense, a dense cloud builds up around Portage Glacier. The cloud becomes a rolling force spreading out over the Turnagain Arm, bringing torrential rains and cooling weather.

The cloud layer is exacerbated by the Harding Ice Field. This massive field of ice, over 1,000 kilometers long, is situated just beyond the crowning points of the Chugach that surround the Anchorage Bowl from the Turnagain Arm to the Matanuska Valley. When summers threaten to grow long and hot, massive clouds begin to gather around the ice field and roll down the graduating foot hills of the range. The change is often heralded with thunder claps; even lightening; both of which were considered a rarity for a climate that was once extremely temperate, with summer temperatures that rarely fluctuated by more than seven degrees.

Internal Geography

The Cook Inlet is a water-rich area. Located at the northern edge of the Pacific rain forest, which monopolizes the coastline of British Colombia, and dribbles into California’s giant Sequoias, the Cook Inlet is replete with hundreds of lakes, rivers, creeks and streams. It’s also filled with a great deal of under-water movement, set off by the melting of mountainous ice caps.

These underground springs have always been known to Alaskan settlers. Wherever a crop of devil’s club and wild celery occur, there is water running just under the surface. In recent years, a great many of these springs have burst out into the open. Housing developments have had problems with water flooding their basements, even in winter, as these springs find new outlets for bubbling to the surface. New road construction bogs down as it accidentally cuts into the vein of one of these swollen springs, flooding the construction site, which must then spend thousands of dollars in diverting the spring and in water removal.

While part of the emergence of new water paths can be blamed on the melting ice caps, part of it is also due to the melting permafrost that accompanies the shrinkage. In nearly all locations of Alaska, one doesn’t need to dig very far under the soil at all before encountering crystal layers of ice scant meters below the surface. This is especially true in the mountainous region or in the far north, where trees adapt by spreading their roots just under the soil, supporting each other with a network of spindly tentacles.

drunken forests
Drunken trees struggling to find purchase in the soil (click to enlarge)

As the glaciers shrink, so does the permafrost. In tundra regions where the thaw is most extreme, entire groves of evergreens twist and sway into crazy shapes, trying to find footing in the swampy terrain. Labeled drunken forests, they have become a common aspect of the Alaskan landscape.

The evergreens are not the only trees affected by the spread of warming soil and consequent liberated water flow. In the warmer regions, birch trees are beginning to feel the effect. Although they are water loving trees, violent rains and increased underwater passages have loosened the soil around them and created more water flow than they can absorb. As one tumbles over from excess pressure, it breaks the network support of its root structure, causing other birch trees to fall too.

Adapting to the Future

A fortunate aspect of Alaska’s virulent wildlife is that it’s extremely adaptable. As quickly as trees fall, young seedlings begin sprouting, flourishing into full-grown seeds within ten years. Brush develops in a single summer. New swampland quickly becomes the home of marine life and water fowl. The greatest hardship is among those whose homes have been lost to flooding or the changes in a river’s currents.

mountains bare of snow
Evidence of disappearing mountain snow (click to enlarge)

The melting glaciers often cause a cooling down effect on what first sets out to be a long, warm summer. Often, there is so much accompanying rain after the first brilliant days, that the inhabitants don’t even notice the warming trend until autumn, when the lingering cooler weather sun reveals the shrinking ice caps on the nearby mountains and warm gusts continue to sigh on days that were once greeted by morning frost.

A few years ago, the unprecedented happened. A particularly long warm spell in autumn brought with it warm winds that completely removed every bit of ice on the nearby mountains surrounding the Anchorage Bowl. Mountains that had typically had small fjords cut into their tops were completely bare by the following year. Now, all the nearby mountains on the Cook Inlet are covered with greenery before the end of summer.

This has caused a slight shift in population growth. Where once the desired habitats were found in the low lands of the Chugach Range, the population has gradually moved up the mountains, finding security in areas where water run-off is swift, and avoiding the real estate agent homes floating just barely above water in low lands close to the inlet.

Locations in the Matanuska Valley that had once been favored for their fertile farmland are now coveted for development projects that search for areas with good drainage. The potential for farming, however, continues, as the glaciers shrink ever smaller. Agriculture has introduced new products that were once deemed impossible to grow in Alaska’s climate; tomatoes, corn and even, with careful cultivation, cucumbers and melons.

The population is slowly following the retreat north, finding habitable land in a climate once considered barely habitable. The memory of snow-capped mountains fades as the summers reveal unbroken greenery from one rolling peak to another, heralding in the new norm. The glaciers that were once massive sheets, roll back from banks of tousled boulders, creating climbing trails for the nimble hiker. Alaska’s mountain glaciers are among the fastest shrinking glaciers in the world, and none are more noticeable than the shrinking glaciers of the Cook Inlet.

Sources & further reading:

http://www.groundtruthtrekking.org/Issues/ClimateChange/GlacierRetreatInAlaska.html

http://www.epa.gov/climatechange/impacts-adaptation/alaska.html

http://blogs.reuters.com/environment/2008/08/25/a-view-from-the-north-alaskas-melting-glaciers/

http://www.adn.com/2012/09/21/2634999/flooding-forces-evacuation.html

Karla Fetrow (2 Posts)

As a native Alaskan, Karla Fetrow advocates the subsistence lifestyle, which minimises the use of our renewable resources as well as creating a greater harmony with nature.


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