Ask the typical person what they saw on their Alaska cruise and one of the first things they'll say is "glaciers." It's practically guaranteed because of the way cruise lines structure their itineraries: In every 7-night Inside Passage cruise, you're almost bound to get three days in port, two days' sailing, and one day (or part of a day) at Glacier Bay, Hubbard Glacier, or Tracy Arm Fjord, home to the North and South Sawyer Glaciers.

But saying those people have really experienced glaciers is like saying someone who drives by 1600 Pennsylvania Avenue in a bus has really seen the White House. All they've really seen is the front door. The most interesting parts all lie inside, behind the white curtains -- or in the case of glaciers, up in the mountains, as the glacier snakes miles and miles back to its source. To get a glimpse of this other world, prospective Alaska cruisers should make the following budget decision: Book a less expensive cabin on the ship, gamble less, buy fewer drinks, buy fewer knickknacks in the gift shops, and use the money you've saved to fund a glacier helicopter trek, preferably one that not only takes you up above the vast bulk of a glacier but also lands you right on one of them for a hike.

If you ask why, here's my simple answer: Because if you don't do it soon, you might not be able to, ever again.

Global Warming and Alaska's Glaciers

In recent years, global warming has begun to have a devastating effect on Alaska's glaciers. All over the state, as well as in other northern lands such as Greenland and the Canadian Arctic, temperatures have risen three to five times more than the global average increase, causing glaciers, sea ice, and permafrost to melt. Juneau's popular Mendenhall Glacier, for instance, lost 656 feet of its ice in 2004 and another 269 feet in 2005, and scientists project that it will recede away from Mendenhall Lake in little more than 10 years, retreating farther and farther into the mountains. Without action on climate change, the great glaciers could disappear forever.

Now, I make my recommendation of a glacier helicopter trek knowing full well that those helicopters burn fossil fuels, adding to the problem that's causing the glaciers to melt in the first place. My recommendation for this is similar to my "save your pennies" advice above: Save up for your helicopter trek. Drive less. Recycle more. Buy carbon offsets. (See Sascha Segan's article or this off-site link for discussions of the best offsets providers.) My point is, if we know what we're in danger of losing, we're more likely to want to save it. Come. See. Care. Then tell your friends.

To understand how glaciers form and behave, I've prepared this little primer. In the section that follows it, I'll provide information on the different glacier treks typically available on Alaska cruise itineraries.

Glaciers 101

  • How They Form: Glaciers form when snow accumulates over time at high altitudes. Successive snowfalls add more and more weight, compacting the snow underneath into extremely dense glacial ice. As the accumulation assumes mass, forming what is known as an ice field, gravity takes over and the ice field begins to flow very slowly downhill through the lowest, easiest passage. The glacier's enormous mass sculpts the landscape as it goes, grinding the shale and other rock and pushing rubble and silt ahead and to the sides. This sediment is known as moraine. Terminal moraine is the accumulation of rubble at the front of a glacier; lateral moraine lines the sides of glaciers. A dark area in a glacier's center -- seen when two glaciers flow together, pushing their ice and crushed rubble together -- is median moraine.
  • Types of Glaciers: Glaciers come in several different varieties. Tidewater glaciers are the kind most often seen on postcards; they spill down out of the mountains and run all the way to the sea. Piedmont glaciers are two glaciers that have run together into one. When seen from above, piedmonts resemble a highway interchange, edged by road slush, with the median moraine looking like lane dividers. There are also mountain or alpine glaciers, which are confined by surrounding mountain terrain and unable to flow. Other types-such as hanging glaciers that spill over rounded hillsides, valley glaciers that are confined by valley walls, and cirque glaciers that sit in basins and are usually circular (as opposed to river-shaped)-are essentially variants on these three main varieties.
  • How They Behave: Glaciers are essentially rivers of ice that flow continually downhill. Depending on temperature and the rate of precipitation, glaciers may either advance or retreat. Think of glaciers as human bodies and snowfall as calories: When the accumulation of snowfall (and resultant glacial ice) is greater than the amount of ice lost to melting and calving (the process whereby ice breaks free from the glacier's face), the glacier grows, which is known as advancing. When the opposite occurs -- when melting and calving outpace new buildup of ice -- the glacier is said to be retreating. Glaciers can also be in a state of equilibrium, where the amount of snowfall roughly equals the amount of melt-off. Even where this is the case, the glacier is still a slow-moving river, always flowing downhill -- it's just that its total length remains the same, with new ice replacing old at a more or less constant rate.
  • Calving occurs when glacial ice reaches the sea, where water begins weakening its structure. Eventually, this process causes large chunks of ice to break off from the glacier's face and crash into the sea, producing a sound like two 1,000-foot bowling balls colliding. This is the behavior that cruisers look for when floating a mile from the glacier face, and who can blame them? It's primordially exciting, and it's also a natural process for which you don't have to feel guilty: Rather than necessarily being a symptom of global warming, calving is really just a symptom of the glacier having reached a large body of water. The process can occur whether a glacier is advancing or retreating. The trouble comes when the glacier's higher reaches can no longer replace the masses of ice lost to calving at its face.
  • An Iceberg Dictionary: Ice that's calved off a glacier floats away as icebergs, which are classified differently depending on their size -- a system that allows one ship's captain to warn another of the relative ice hazard. Very large chunks are officially called icebergs; pieces of moderate size (usually 7-15 ft. across) are known as bergy bits; growlers are slightly smaller still, at less than 7 feet across, with less than 3 feet showing above water; and brash ice consists of any random smaller chunks. And remember the adage: What you're seeing is only the tip. Most of the berg really is below the water.

Glacier Excursions in Alaska

The following glacier excursions are typically offered on Alaska cruise itineraries:

  • Extended Helicopter Glacier Trek (Juneau): This is the heavyweight champ, a 5-1/4 hour excursion that includes about three hours on Juneau's Mendenhall Glacier plus some 30 minutes of flight time round-trip from Juneau Airport. At the helicopters' home base, participants are outfitted with water-resistant pants, jackets, and gaiters, plus helmets and heavyweight boots. From the helicopter, you'll be able to see how truly stupendous glaciers really are, stretching for miles back into the mountains, far beyond what anyone can glimpse from sea level. After landing, you'll be issued an ice axe and spiked crampons for your boots, and given some basic instructions. The most important rule? Follow your guide, only walking where he walks. What to you looks like smooth ice might actually be snow covering a deep crevasse, a lesson I learned firsthand in May when I stepped a little too far to the right and fell in up to my chest -- not so bad, considering how deep that hole could have been. The glacier is like another planet, with its own logic and environment. As you walk, you might see vast rolling fields of white off to one side; on another, maybe jagged pinnacles concealing blue crevasses and mysterious ice caves. Amidst it all, glacial springs, pools, and streams carry meltwater that could have frozen 200 years ago, before pollutants got into the groundwater. Fill up your water bottle: It's some of the purest stuff you'll ever taste. Typical cost: $515 per person.
  • Helicopter Glacier Trek (Juneau): Similar to the above, but with two hours on the glacier instead of three. Typical cost: $400 per person.
  • Mendenhall Glacier Walkabout (Juneau): The least strenuous of the trekking options in Juneau, combining 30 minutes of flightseeing and one hour on the ice. Typical cost: $350 per person.
  • Mendenhall Glacier: Ice Age by Helicopter (Juneau): This trip combines a helicopter flightseeing tour with a landing on the Mendenhall, giving you 20 to 25 minutes to walk around the landing site and learn a bit about the glacial surface. Typical cost: $275 per person.
  • Glacier Discover by Helicopter (Skagway): Similar to the Mendenhall Ice Age tour, this excursion lifts off from Skagway's waterfront and flies over the Chilkat, Ferebee, and/or Meade glaciers before landing at a site selected for that day's conditions. Participants spend approximately 40 minutes in the air and 40 minutes on the ice. Typical cost: $265 per person.
  • Glacier Hiking (Alyeska/Anchorage): Here's one that dispenses with helicopters entirely, beginning instead with a ride up the aerial tram from the Alyeska Prince Hotel to the Glacier Express Lodge. From there, participants hike one hour to a ridge with views of the seven glaciers surrounding the Girdwood Valley. At the edge of one glacier you'll be outfitted for ice-hiking and travel out onto the glacier itself. Typical cost: $140 per person.
  • Helicopter Flightseeing with Glacier Landing (Denali): The flightseeing portion of this trip typically takes in the Susitna and Nenana Glaciers and includes a landing and walkabout on the Yanert Glacier. Typical cost: $400 per person.
  • Mt. McKinley Glacier Landing from Denali National Park (Denali): This flightseeing tour takes in Ruth Glacier, Don Sheldon Amphitheater, and many of the glaciers and peaks on the mountain's south side, and includes a landing and brief glacier walkabout. Typical cost: $400 per person.
  • Mt. McKinley Flyer with Glacier Landing (Talkeetna): After a flightseeing tour that takes in the south side of the Alaska Range, your helicopter will descend into the huge Don Sheldon Amphitheater and land on Ruth Glacier, where you'll have approximately 20 minutes on the ice. Typical cost: $290 per person.
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