Snow, Sea Ice, Glaciers, Ice Shelves, Ice Sheets…and More!
What’s the difference between the things listed in the title above? Today I’ll give you some basic information which will help you learn the things they have in common and what is particular to each. This information is important because WISSARD scientists are studying the movement of the West Antarctic Ice Sheet, subglacial water environments, and glaciers.
But first, here is an awesome animation that I found through a good friend and ANDRILL education colleague, Matteo Cattadori. Created by the combined efforts of Matteo (progettoSMILLA.it) and IPRASE (Trentino Provincial Institute of Education Research and Experimentation), this animated map shows many important bits of information such as size of other continents compared to Antarctica, sea ice changes from winter to summer, and names of the oceans that connect with the Southern Ocean which surrounds Antarctica. The website is in Italian, but you can navigate the map easily, even if you do not know this language.
Some helpful hints: once the map loads on your screen, use the tools at the bottom of the map to guide you.
** The circular yellow buttons on the bottom left of the map are to show you the size of different continents put inside of Antarctica to show scale. Just click on the yellow circles to see this happen. By clicking the arrow buttons you can rotate the position of the continent to the left or right. The straight up arrow moves the continent back to its starting position. Very cool features!
** The snowflake button can be clicked to show how the amount of sea ice increases during the winter months in Antarctica. By clicking the button again, you will see how much ice is present during the summer months (the sun icon).
While I was checking out this animation, I clicked on the tiny icon for NSIDC (bottom right corner). What I found was a website full of great information I’d like to relay to you. Any information that is in “italics” was retrieved from the website. Anything in “print” is my own text. All photos are my own, unless otherwise noted.
The National Snow and Ice Data Center, University of Colorado, Boulder
What is the cryosphere?
Some places on Earth are so cold that water is a solid—ice or snow.
Scientists call these frozen places of our planet the “cryosphere.” The word “cryosphere” comes from the Greek word for cold, “kryos.”
Why does the cryosphere matter?
The cold regions of our planet influence our entire world’s climate. Plus, the cryosphere is central to the daily lives of the people, plants, and animals that have made it their home.
Where is the cryosphere?
When scientists talk about the cryosphere, they mean the places where water is in its solid form, where low temperatures freeze water and turn it into ice.
People most often think of the cryosphere as being at the top and bottom of our planet, in the polar regions. We call the area around the North Pole the Arctic and the area around the South Pole the Antarctic. But snow and ice are also found at many other locations on Earth.
Sea ice is one important aspect of both the Arctic region and Antarctica.
The photo above shows the sea ice in McMurdo Sound, Antarctica. Right now that sea ice is breaking apart and melting. I see an increasing amount of ocean each day.
The North Pole is covered by a cold ocean called the Arctic Ocean. In the Arctic Ocean, sea ice grows in the winter and shrinks in the summer.
Frozen ground and permafrost ring the Arctic Ocean. Glaciers, snow, and ice cover the nearby land, including a thick sheet of snow and ice covering Greenland.
Antarctica, at Earth’s South Pole, is an icy continent. A huge ice sheet covers the land mass of Antarctica and, in some places, shelves of floating ice extend into the ocean. The outer sections of ice break off or “calve” from these shelves and form icebergs. The icebergs float in the oceans, melting and falling apart as they drift into warmer waters.
The frozen lands of the cryosphere exist beyond the polar regions, in places like Mount Rainier National Park in Washington.
The cryosphere also exists in places far away from the cold poles, at high elevations. For example, the snow on Mount Kilimanjaro is in Africa. Frozen soil can be found high in the mountains of the United States, as well as in the northern reaches of Canada, China, and Russia.
The cryosphere expands during the cold winter months. Seasonal areas of the cryosphere include places where snow falls, and where soil, rivers, and lakes freeze.
What is in the cryosphere?
Snow, ice, or both are key ingredients in every aspect of the cryosphere, including sea ice, glaciers, ice shelves, icebergs, and frozen ground.
Snow is precipitation made up of ice crystals. When cold temperatures and high humidity levels combine in the atmosphere, snow crystals form. As long as air temperature remains below freezing, the crystals will fall to the Earth as snow.
- can be found all over the world, even near the equator at high elevations
- reflects sunlight and affects our planet’s climate
- provides a habitat for some animals and plants
- supplies water for people, plants, and animals around the world
- is an important part of the world’s climate.
Ice is the basis for glaciers, sea ice, ice shelves, icebergs, and frozen ground.
Ice forms when temperatures drop below the freezing point and liquid water becomes a solid, creating a tightly bonded substance. Ice is a key ingredient in glaciers, sea ice, ice shelves, icebergs, and frozen ground.
Naturally occurring ice:
- exists all over the world, but mostly forms in the high latitudes, at high elevations, or at night when temperatures cool
- in oceans, lakes, and rivers may not be as common if climate continues to change and temperatures warm
- provides water for people, animals, and plants
- on lakes and in oceans can get so thick that special ships called icebreakers have to create a path through the ice
- can tell scientists about the past climate of Earth through ice cores.
Arctic sea ice influences our entire planet’s climate.
Sea ice forms when water in the oceans is cooled to temperatures below freezing. Most sea ice forms in the Arctic and Antarctic Oceans.
The following two sea ice photographs were taken by Gordon Bain while he was on an expedition with the Australian Antarctic Division.
Aren’t the differences fantastic?
- does not raise sea level when it melts, because it forms from ocean water
- is closely linked with our planet’s climate, so scientists are concerned about its recent decline
- fills a central role in the lives and customs of native Arctic people
- provides a place for polar bears, seals, and other animals to live
- is one way that scientists study the effects of climate change.
Glaciers are thick masses of ice on land. The ice has built up from many seasons of snowfall. Glaciers move downhill very slowly.
- cover 10 percent of the world’s land
- are smaller, today, than they used to be because of climate change
- sometimes look pink because of the algae living in the top layers of the snow and ice
- store 75 percent of the world’s fresh water and provide water for many people around the world
- change the land they flow through, carving landscapes with their weight.
Ice shelves and icebergs
Ice shelves are platforms of ice that form where ice sheets and glaciers move out into the oceans. Ice shelves exist mostly in Antarctica and Greenland, as well as in the Arctic near Canada and Alaska. Icebergs are chunks of ice that break off glaciers and ice shelves and drift in the oceans.
Ice shelves and icebergs:
- raise sea level only when they first leave land and push into the water, but not when they melt in the water
- break off and melt as temperatures rise; in 2002, Antarctica’s huge Larsen B Ice Shelf shattered in only a few months, sending hundreds of icebergs into the ocean
- provide shelter for krill, small fish that penguins, seals, whales, and sea birds eat
- are one important area of study for a wide range of scientists who study biology, glaciers, climate, and other fields
- may hold clues to the future of ice sheets and glaciers in a world with warming temperatures.
Frozen ground is soil or rock in which part or all of the water has frozen. If the ground is frozen all year long, we call it “permafrost,” or permanently frozen ground.
- exists mostly in the Arctic and Antarctic, but frozen ground can also be found at high elevations
- has begun to melt as climate warms
- often has an “active layer” near the surface, where plants can live because the soil is thawed for at least part of the year
- creates problems for people who are building structures, roads, or dams because it can shift them when it melts
- stores greenhouse gases like carbon and methane; scientists are studying how these gases will affect climate as temperatures warm and permafrost thaws.
Learn more about snow, ice, glaciers, ice sheets, ice shelves, sea ice…follow the links below!
These links from The National Snow and Ice Data Center website are great places for more learning!
A great photo gallery to look through!
Cryosphere Quick Facts
Photos and facts about: Arctic sea ice, ice sheets, ice shelves, and icebergs.
Is the cryosphere sending signals about climate change?
The cryosphere, where water is frozen, provides us with direct, visual evidence of temperature changes. Ice and snow exist relatively close to their melting point and may frequently change from solid to liquid and back again, resulting in dramatic visual changes across the landscape as features like glaciers and ice sheets shrink or grow.
Research in Harsh Conditions:
Field work on the East Antarctic Plateau may sound like a fun adventure. But imagine coming in from working in the constant freezing wind to warm up in a tent that is 28°F. As NSIDC researcher Ted Scambos says, “Staying warm and protecting your skin are the main concerns. Temperatures are frigid even in summer, -5 to -22°F. But the wind is the real danger.” Wind chill temperatures can reach -51°F. Now imagine living and working in those conditions for weeks.
** Ice Trek: Exploring the Lifecycle of a Drifting Antarctic Iceberg
** Arctic Megadunes (huge snow dunes)
** The Arctic Ice Dynamics Joint Experiment (research from 1972, 1975, 1976 in the Beaufort Sea; the first major Western sea ice experiment to answer questions about sea ice movement and changes in response to the influence of the atmosphere and ocean)
** Cryosphere Glossary
** Cold Link: Digital Library for Earth System Education
** Atlas of the Cryosphere
** Repeat Photography of Glaciers (photographs from the same location, years apart; showing changes of a particular glacier)
** Data on Virtual Globes: Google Earth files
** Print and Multimedia Resources