The opportunity to see Alaska’s glaciers up close on the open water is a favorite on many bucket lists. If you’re planning to go on a cruise around Alaska’s mainland or the Aleutian Islands, you’re probably looking forward to the breathtaking tundra scenery. But what makes the glaciers a sight worth seeing? Keep reading for some lesser-known facts about glaciers and other travel knowledge.
In This Article
- What Is a Glacier and Why Is It Important?
- Glaciers Are a Rare Sight Today Compared to the Past
- Glaciers Store Most of the Earth’s Fresh Water
- A Glacier Can Take Centuries to Form
- Glaciers Are Considered a Type of Monomineralic Rock
- Glaciers Are Classified by Size
- Glaciers Can Move About 50 Feet Per Day
- Glaciers Produce Rock Flour
- Glaciers May Appear Blue
- Glaciers Can Form Over Active Volcanos
- Glaciers Can Form Near the Equator
- They Are Unlikely to Contain Fossils
- There Are Surging Glaciers
- Tidewater Glaciers Can Shoot Ice Like Missiles
- Glaciers Have Texture
- Some Glaciers Are Ancient
- The World’s Largest Glacier Is in Antarctica
- Glaciers Are Widespread
- NASA Carefully Observes Glaciers
- Glaciers Leave a Trail
- Glaciers Play a Role in the Earth’s Homeostasis
- Glaciers Have Names
- Where to Find Glaciers in Alaska
- Spot Alaskan Glaciers With Windstar Cruises
What Is a Glacier and Why Is It Important?
Glaciers are large, slow-moving deposits of ice and snow that drift down into the ocean, forming solid, floating structures of crystalline ice. Alpine glaciers initially form on mountains and tend to move in the direction that gravity pushes them in, whereas ice sheets spread out from the center as they continue growing. The origin of a glacier is melted snow, requiring an area of heavy snowfall to have the opportunity to refreeze and collect into a pocket of solid ice.
Glaciers slowly shape the landscape even in modern times. Glacial ice has been carving valleys and depositing minerals in neighboring regions long before humans dominated the Earth. For more interesting glacier facts, expand your knowledge with the following list.
1. Glaciers Are a Rare Sight Today Compared to the Past
Only around 10% of the Earth is covered by glacial ice, which includes the expansive polar ice caps and sheet ice in Greenland and Antarctica. Of that number, you can find less than 1% of all glaciers in Alaska, which is an accessible location to explore for those who live in the United States or Canada.
The current composition of the Earth is very different from the last ice age, when glaciers covered about 32% of the land. The world had a smaller scale ice age starting in the early 14th century and ending right around the 19th century. During that time, glaciers were able to maintain homeostasis and continue growing without disturbing flora and fauna.
They have been so rare and slow to develop in recent years that animals living in the colder regions have had enough time to adapt to their presence.
2. Glaciers Store Most of the Earth’s Fresh Water
This glacier fact is difficult to fathom. The glaciers you can view today store around 69% of the Earth’s fresh water as ice. That is an impressive amount of water for the small surface area glaciers take up. In the United States alone, glaciers only cover about 35,000 square miles, and nearly all of that glacial ice is in Alaska, where temperatures stay cold enough for it to develop.
If all glaciers melted, the sea level would rise across the globe by around 230 feet. This would be significant enough to flood coastal cities that currently rest below or near sea level.
3. A Glacier Can Take Centuries to Form
Glaciers form so slowly that the process can take longer than you might expect. Glacial ice accumulates over hundreds of years to build into permanent structures. The melting season must be shorter than the cooling period for this to happen. Ice that melts too quickly loses its glacial nature when the snow crystals deteriorate, spilling as fresh water into the oceans, unable to entirely reform during the next cooling period.
4. Glaciers Are Considered a Type of Monomineralic Rock
Rocks formed from a single mineral are monomineralic, and glaciers count as this type of rock because of the crystalline structure of the snowflakes that serve as their building blocks. As snowflakes combine, the ice crystals inside a glacier expand to be about as large as baseballs, making glaciers surprisingly strong. A chunk of solid glacial ice behaves exactly like a rock until temperatures increase enough for it to melt into liquid water.
5. Glaciers Are Classified by Size
In order for U.S. Geological Survey scientists to consider an ice body to be a glacier, the ice must cover at least 0.1 square kilometers. This is large enough for the ice to establish some permanency. That means even the smallest glaciers are nearly 25 acres across. In order to get that large, a significant amount of snow must land over a period of several years.
6. Glaciers Can Move About 50 Feet Per Day
Although they travel slowly, glaciers are capable of sliding across the land with the help of gravity. The average speed of a glacier depends on its size and shape and the surrounding terrain. Each day, a glacier moves around 50 feet, but some are over double as fast and others are much slower. Eventually, smaller chunks of ice drop into the ocean to become icebergs.
7. Glaciers Produce Rock Flour
Glaciers rub against the sediments below to create a fine mineral powder with the texture of silt. Grated bedrock that spills into a small body of water suspends rather than sinking to the bottom. This produces a stunning visual effect by turning the water a bright turquoise color.
8. Glaciers May Appear Blue
Solid glaciers are unable to absorb blue light, so they appear to have a blue glow to the naked eye and your camera. The ice crystals reflect blue light while letting other wavelengths pass through them. This is why many photographs of glaciers have a natural azure tinge.
9. Glaciers Can Form Over Active Volcanos
It might seem contradictory that a volcano would receive enough snowfall to produce a favorable environment for a glacier, but it has happened before. In frigid temperatures, the crust of an active volcano can remain cool enough for the snow to accumulate on top. When Iceland’s Grímsvötn volcano erupted in 1996, its lava melted the glacial ice encasing it and flooded the surrounding areas, causing several million dollars in damages.
10. Glaciers Can Form Near the Equator
Glaciers are known for forming in the coldest locations on Earth, but Mexico and the Ecuadorian Andes also have some. Mountainous regions are ideal for the formation of alpine glaciers, which slowly slide down the cliffs until they carve and shape the valleys below.
11. They Are Unlikely to Contain Fossils
You might have heard of researchers digging well-preserved woolly mammoths out of the ice, but as the outermost layer, a glacier is the least likely place where you would see a mammoth. Instead, fossils can be found in the permafrost under the ground. Permafrost is composed of frozen sediments where water has leaked into the soil and become trapped.
In 1991, a tourist did make an unusual discovery of a mummy preserved in the ice of the Similaun Glacier, estimated to have perished as long ago as 3350 BC. He became known as the “Ice Man” of the Tirolean Ötztal Alps and was later given the name Ötzi. A rare find like this can happen when the glacial ice recedes enough to reveal a past from thousands of years earlier.
12. There Are Surging Glaciers
While most glaciers travel slowly, some go through periods of rapid advancement as they move down a mountainside or a steep incline. If you know where to look, you can observe these glaciers when they’re in a more active phase. Many of the surging glaciers can be found in Alaska. The Russell Fjord Wilderness has a glacier that usually travels at average speeds but surges every few decades or so.
13. Tidewater Glaciers Can Shoot Ice Like Missiles
When a glacier calves, it cracks at the front near the ocean, and pieces of ice drop into the water. When tidewater glaciers like the Worthington Glacier calve from under the water, they launch ice, causing impressive splashes. Tidewater glaciers calve on a daily basis, making this a possible sight to record.
14. Glaciers Have Texture
Ridges and crevasses form on the surface of glaciers as they move. Rather than remaining smooth like a snowball, they gradually become more textured. As a glacier slides over bedrock, its internal structure is exposed to stress from motion, which releases in the form of cracks. A glacier can also gain texture when different parts travel at uneven speeds from the rough terrain.
Glaciers tend to move slightly faster in the middle, with the sides scraping against cliffs and rock. If you tour a glacier and have the opportunity to walk on its surface, make sure to obey your guide’s directions and watch your step for crevasses.
15. Some Glaciers Are Ancient
A glacier can take centuries to form, but several are far older. Scientists estimate that some glaciers have been around for millions of years. In fact, some researchers found an 8 million-year-old glacier in Antarctica. Glaciers can stay frozen for so long because summer temperatures stay cool enough to preserve them until fresh snowfall repairs the outermost layers.
16. The World’s Largest Glacier Is in Antarctica
Antarctica is the home of most large glaciers. The Lambert Glacier is the world’s biggest glacier, estimated to be a massive 100 kilometers wide and 400 kilometers long. Its total depth is about 2.5 kilometers, or nearly 2 miles, of solid ice.
17. Glaciers Are Widespread
Most of the world’s glaciers are found in Greenland or Antarctica, but every continent has some glaciers. Areas of at least 47 countries have conditions that favor their development. Glaciers can also be found on other planets and moons. It’s believed that they might have once occupied Earth’s neighbor Mars, carving the landscape similar to our own planet’s surface before the ice eventually dried up.
18. NASA Carefully Observes Glaciers
NASA uses certain satellites and aircraft to keep Earth’s glaciers under close observation. IceBridge is responsible for recording the annual amount of growth and depletion of the prominent glaciers, and the GRACE satellite collects data on shrinking glaciers and sea level rise.
It’s also fairly common to see field researchers and glaciologists studying Alaska’s popularly toured glaciers. Many scientists and local university students are fascinated with the icy giants and hope to discover important clues about climate change among them.
19. Glaciers Leave a Trail
Glaciers flow like rivers running in slow motion and weigh thousands of metric tons. They are large and heavy enough to leave noticeable impressions in the sediments they slide over, carving deeper valleys and scraping against cliffs. They are also strong enough to transport rocks, boulders and other materials that become trapped in the ice. You can usually tell where a glacier has been even if it’s hard to detect any movement.
20. Glaciers Play a Role in the Earth’s Homeostasis
Both land and oceans are dark in color, causing them to absorb enough sunlight to trap heat. Even the thickest ice reflects sunlight, however. Glaciers take up a large surface area, playing a valuable part in regulating the Earth’s habitable temperatures.
21. Glaciers Have Names
Much like mountains and oceans, all of the prominent glaciers are given names. Some of Alaska’s most famous are the Mendenhall, Exit and Hubbard Glaciers. The term “glacier” is straightforward on its own, stemming from the French word for ice, “glace,” pronounced “glah-say.”
Where to Find Glaciers in Alaska
Alaska is one of the best places to go for glacier tours and scenic cruises. Below are a few of the best to look out for:
- Prince William Sound: For a closer view of the tidewater glaciers towering high above the ocean, go on a cruise around the Prince William Sound. The majestic blue pillars of ice make up the largest collection of tidewater glaciers anywhere else on Earth. The waters are turquoise near the shallows from the rock flour, and in the summer, the beaches are lined with abundant green.
- Columbia Glacier: This glacier has been in decline, making it highly active. Coming near the Columbia Glacier on a cruise line might be the perfect chance to see some calving and ice breaks. You can access the quickly accumulating ruins of ice via the Prince William Sound.
- Exit Glacier: Named for the finishing length of a 1968 expedition through the Harding Icefield, Exit Glacier can be reached on foot after you disembark from a cruise. This glacier is smaller than some of the others, but its recession over the years has made it a common interest of glaciologists.
- Twin Sawyer Glaciers: For a closer look at stable tidewater glaciers, join a cruise through the narrow Tracy Arm. You will have an excellent view of the cliffs on either side of the inlet as you pass through to the Twin Sawyer Glaciers, with waterfalls pouring down and the occasional visible cave face.
- Hubbard Glacier: You can take a cruise to see this large tidewater glacier near the coast of Yakutat. With most of its massive ice stores below the ocean’s surface, this glacier still stands around 400 feet above the ships that come to visit.
Spot Alaskan Glaciers With Windstar Cruises
Would you like to go hunting for majestic glaciers on your next vacation? The United States is home to a large number of ice formations in its northernmost state. Go on a Windstar Cruise to Alaska and enjoy the premium onboard services and sight-seeing tips from our knowledgeable staff. Our small ship sizes can enter narrow inlets, making for an engaging travel experience that gets you close to nature.
If you have questions about our cruise packages or which glaciers you might encounter on a cruise with us, please contact us online to learn more.