Frozen in Time, Glaciers Age Before Your Eyes

What strikes a Californian seeing a glacier for the first time is not how slowly it moves, but how fast. Glaciers can grow, mature and retreat in the matter of a human life span, giving scientists an opportunity to predict their behavior and, often as not, find out they were wrong.

Glaciers break off in pieces right in front of you, then topple off into a new life cycle as icebergs. They carry on their faces the lives they have lived, growing wrinkled in middle age, bearing dark lines that are the road map of earth chewed up beneath them.

Short of earthquakes and volcanic eruptions, how often do we have an opportunity to see the face of the earth change before our eyes?

Travel brochures suggest that you must see glaciers from the deck of a cruise ship or miss out. Not true. Even if you’re on a business trip to Alaska, or abhor the idea of wilderness trekking, you can get close to a glacier.

The power of a great glacier is like the presence of a great mountain, only where a mountain stands tall, almost holy, the glacier flows around it, ripping away at mountain walls, churning unseen rock beneath its mass into fine glacial “flour.”

Often, glaciers flow out into a cement-colored river at its base. To see one working--and working is the word for it--is to understand, for example, why Yosemite is a valley.

Each glacier is unique, born when snow accumulates and compacts to a point at which its own weight finally forces it downhill, and it begins to flow. Almost all air bubbles are pressed out of the ice in this process, turning it into a prism unlike any ice you ever saw in your refrigerator. This hard, pristine substance absorbs all but the shortest wave lengths of color, leaving the ice turquoise.

In Alaska are half the world’s glaciers--more than 100,000--ranging from the tiniest “hanging glaciers” that can look like mere dribbles of white paint on mountaintops, to one immense field of ice called Malaspina that is larger than Switzerland. Happily, the largest glaciers are among the most accessible because the heaviest snows--400 inches a year and more--occur in southern Alaska.

From Anchorage, Portage Glacier is 50 miles southeast on the Seward Highway alongside a treacherous fiord called Turnagain Arm. It was so named because Capt. James Cook, who sailed up it in 1778, looking for the elusive Northwest Passage, ordered his explorer boats to turn back as soon as he saw them foundering in the treacherous waters.

The Arm, by the way, has one of the most dramatic tidal bores in the world, that sends walls of water (up to 38 feet high) rushing over the mud flats.

The drive from Anchorage to Portage alone is worth the trip. Bald eagles fish in Turnagain Arm. Moose and mountain sheep occasionally can be seen from the road. The damage wreaked by the Good Friday earthquake of 1964 is more visible along this stretch than in Anchorage, where there is a museum dedicated to the disaster.

Whole sections of countryside fell 10 feet in some areas along the highway, killing forests with salt water. Still visible are houses that sank into the earth. One, open to visitors, is a curious split-level affair, half above ground, half below.

Arriving at the Portage Glacier Visitor Center, you see a modest lake a few miles long in which improbable dollops of ice appear to be sailing across the surface in a strong wind.

Some of these icebergs are 60 and 70 years old, melting slowly in 36-degree water. Unseen from shore, the icebergs support a single life form: pin-sized ice worms that once were considered mythical. They live on the icy surfaces at precisely 32 degrees, eating air-borne algae and pollen.

The visitor center, a beautifully executed multimedia museum, offers a plastic pedestrian tube through which visitors can walk out over the lake, protected from what can be hurricane-force storms even in summer.

Don’t avoid glaciers in overcast weather; icebergs are bluer on gray days, and seeing glaciers on sunny days robs you of sensing the very reason for their existence.

The Portage center is built upon terminal moraine, a heap of boulders and natural debris carried downhill by the glacier at the end of its advance almost a century ago.

In 1913, the glacier ended where the parking lot is today. Now it lies three miles beyond the lake that was formed during its retreat. Although technically the Portage Glacier advances by 15 inches a year, its face melts faster, producing a net retreat of some 300 feet a year.

The big mystery is what happens in the year 2020, when it is due to recede to the end of the natural lake basin. Some scientists predict it will simply stop and rest as it did at the turn of the century. Others think it will begin a new advance, turning the lake into a bed of ice once again.

The predictions are based upon formulas that take into consideration speed, weight, mass, topography, global warming, snowfall patterns and other factors.

August is the best month to see Portage “calve.” For a closer look, a boat carries visitors near the face of the glacier, gently nudging icebergs out of its way.

The Chugach National Forest, in which the center is located, is the second-largest national forest in the United States, covering nearly six million acres, a third of which is nothing but moving ice fields.

Portage offers a lodge and camping areas. Several companies offer part-day bus tours that leave from Anchorage. The drive is an easy one, however, and if two are traveling, renting a car will not only give you a chance to stop along Turnagain Arm, it will probably be cheaper.

Because of the sheer vastness of Alaska, most glaciers are visible only by air. Dozens of air taxi services offer prearranged and custom-designed flights over major glaciers.

Flying over Alaska is almost the only way to appreciate the immensity of the state. Flights range from about $150 to $250 per person for two to three hours.

When flying, make sure weather is good. Winds can prevent planes from getting as close as you’d like to the glaciers.

Viewed from a plane on a windy day, the giant Matanuska Glacier north of Anchorage, for example, resembles the trunk of some immense albino elephant. You get an appreciation for its size, but because you are so high, the giant crevasses, which can be a hundred feet deep, are reduced to wrinkles.

Helicopter tours range from $149 to $300. Some around Juneau offer an opportunity to walk out onto a glacier. Some offer brief hikes out over Mendenhall Glacier and guided float trips down the river at its base.

The dramatic tidewater glaciers advertised by cruise lines are still incomparable. But even if you don’t want a whole cruise package, you can still see them.

Glacier Bay, the one most often photographed, is reached from Juneau. Prince William Sound, home of the mighty Columbia Glacier in Prince William Sound, is usually reached from Valdez or Anchorage.

Glacier Bay is one example of how dramatically glaciers change. When George Vancouver first saw Glacier Bay in 1794, it was merely an indentation in a river of ice a hundred miles long.

When naturalist John Muir arrived less than a hundred years later, the glacier had receded nearly 50 miles, creating a bay. Today, Glacier Bay National Park and Preserve has more than 20 large glaciers and many smaller ones.

One calves such volumes of ice that boats must stay two miles away for safety. Access to park headquarters is only by air or boat. But both make frequent runs from Juneau. Reserve flights, overnight cruises and lodging (at the single lodge in the park) in advance.

Three-day cruises range from about $400 to $600, two-day cruises from $300. You can also boat, camp or lodge at Glacier Bay. No reservations are required for campers.

From Anchorage or Valdez, you can visit the immense Columbia Glacier, a wall of turquoise ice that dwarfs large cruise ships. Take the train to Whittier (no road reaches the town), where boats offer tours for visitors to see 26 glaciers around Prince William Sound for $119.

One of the most highly recommended trips is a train ride from Anchorage along Turnagain Arm to the port of Seward. Boat tours are timed to depart upon the train’s arrival, taking visitors out into Resurrection Bay for a panoramic view of puffins, different species of whales and distant glaciers.

A daylong version requires an overnight stay in Seward but goes deep into the Kenai Fiords, affording a more intimate view of glaciers.