Oceanographer Ted Maksym tells us about four different types of sea ice, and what they might indicate about the changing Arctic.
With the Arctic's annual summer ice cover hovering at record lows, a new record low in global sea ice coverage recorded earlier this year, and a large crack threatening the collapse of a large ice shelf in Antarctica, it can feel like the news about Earth’s polar ice caps is all bad.
But for researchers who spend time in the frigid polar seas, ice is also a beautiful and unique phenomenon. Ever heard of frazil ice? How about pancake ice? Far from goofy names, these are key steps in the evolution of sea ice from water to a solid sheet. Oceanographer Ted Maksym shares his insights into the ice at Earth's poles.
Frazil ice (left) and nilas ice (right).
- Why do you think it is important to have names for different types of ice?
- Why don’t pancake ice pieces stick together when they bang into one another?
- How do ocean conditions affect Antarctic ice? Arctic ice?
- What does the presence of frazil ice in the Arctic tell us about ocean conditions in that region?
- Brine is water saturated with salt. Why does brine freeze the sea water below the surface? What does that tell you about the freezing point of fresh water versus salt water?
- Introduce students to the different layers of the ocean with this investigation of the effect of temperature and/or salinity on water density. Look back at the interview and have students brainstorm ways to engineer the different ice types discussed (shuga, nilas, frazil, pancake). Make sure to provide sea ice background information, you can even find a sea ice board game on this site. After reviewing each group’s ice engineering plan, let students try to create their different ice types. Have them reflect on the success of their process and revise it if necessary.
- What is the deal with brinicles? The brine becomes supercooled, so when it comes into contact with the surrounding salt water, it freezes it. Experiment with supercooled liquids by creating fruit pops from supercooled water.
- Did you know that ice needs a “seed” to get started? Learn more about ice nucleation and bacteria with this activity about the microbiome in our skies.
Next snowstorm, grab a magnifying glass and try snowflake hunting!
Vocabulary: Antarctica, Arctic, ice crystals, ice floes, sea ice, brine
Next Generation Science Standards: CCC1: Patterns, ESS3.C: Human Impacts on Earth Systems, PS3.B: Conservation of Energy and Energy Transfer. Can be used to build towards MS-PS1-4, MS-ESS3-3, HS-ESS3-6.