ClassX Video Lessons Youtube Channel MinuteEarth These tiny shells know how much ice there is on Earth
Have you ever picked up a tiny seashell and wondered about its story? Each of these small shells was once the home of a tiny, single-celled creature called a foram. Even though forams don’t have eyes, brains, or limbs, they have a special ability to take materials from seawater and build their shells from a mineral called calcium carbonate. But here’s the cool part: each shell holds a secret number that tells us how much ice and snow there is on Earth!
These tiny sea creatures can actually give us clues about the amount of snow and ice on mountaintops, ice sheets, and glaciers all over the world. They do this by using two types of oxygen from seawater: regular oxygen, which has eight protons and eight neutrons, and heavy oxygen, which has eight protons and ten neutrons.
Water molecules with regular oxygen are lighter, so they evaporate more easily from the ocean’s surface and form clouds. Since ice sheets are made from clouds, they store a lot of this regular oxygen. When the Earth is colder, more regular oxygen is trapped in ice sheets, leaving less in the oceans.
As forams build their shells, they capture the ratio of regular oxygen to heavy oxygen in the seawater. This ratio helps scientists figure out how much ice is at the poles and what the average global temperature is. While we have thermometers and satellites to measure these things today, they only show us what’s happening right now. Forams, on the other hand, have been recording this information for hundreds of millions of years, creating a historical record on the ocean floor.
By drilling into the seafloor and pulling up long cores of ancient sediment, scientists can uncover a nearly continuous record of Earth’s temperature changes over time. Much of what we know about our planet’s climate history comes from these tiny marine organisms and their amazing shells.
This fascinating research is supported by the Heising-Simons Foundation, which is dedicated to unlocking knowledge and possibilities. To learn more about the Foundation and its Science program, which supports fundamental research in the physical sciences, visit www.heisingsimons.org.
Use clay or playdough to create a model of a foram shell. Pay attention to the details and imagine how these tiny creatures build their homes. Once your model is complete, discuss with your classmates how the shell’s structure might help scientists understand Earth’s ice levels.
Conduct a simple experiment to understand the concept of isotopes. Use two different colored beads to represent regular and heavy oxygen. Create different “water samples” with varying ratios of these beads and discuss how these ratios can indicate changes in Earth’s climate.
Work in groups to create an interactive timeline of Earth’s climate history. Use information from foram research to highlight key periods of climate change. Present your timeline to the class and explain how foram shells have contributed to our understanding of these changes.
Participate in a simulation of a seafloor drilling expedition. Use straws and layers of different colored sand or soil to represent sediment layers. “Drill” into your model to extract a core sample and analyze the layers to infer historical climate data, just like scientists do with foram shells.
Research a specific aspect of foram studies, such as their role in the carbon cycle or their use in paleoclimatology. Create a presentation to share your findings with the class, highlighting how these tiny organisms provide valuable insights into Earth’s past and present climate.
Here’s a sanitized version of the provided YouTube transcript:
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Each of these sea shells is actually quite small, as each was once home to a tiny single-celled marine lifeform called a foram. Although they lack eyes, brains, or limbs, forams manage to extract materials from seawater and construct their homes from the mineral calcium carbonate. Interestingly, each shell contains a number that indicates the amount of ice and snow present on Earth.
This means that a single-celled sea creature can provide insights into the total snow and ice on all the mountaintops, ice sheets, and glaciers across our planet! Here’s how it works: the number in the forams’ shells is derived from two types of oxygen they obtain from seawater—regular oxygen, which has eight protons and eight neutrons, and heavy oxygen, which has eight protons and ten neutrons.
Water molecules with regular oxygen are slightly lighter and more likely to evaporate from the ocean’s surface, forming clouds. Since all the ice in the ice sheets originates from clouds, these ice sheets serve as a storage facility for regular oxygen. In colder global climates, more regular oxygen is stored in the ice sheets, leaving less in the oceans.
As forams build their shells, they effectively capture the ratio of regular oxygen to heavy oxygen in the seawater. This ratio allows us to determine the amount of ice at the poles and the average global temperature. While we can measure these factors directly with thermometers and satellites, those tools only provide current data. In contrast, forams have been recording this information for hundreds of millions of years, creating a historical archive on the seafloor.
By drilling down and extracting a long core of ancient sediment, we can recover a nearly continuous record of Earth’s temperature fluctuations over time. Much of what we understand about our planet’s past climate can be attributed to these tiny marine organisms and their intricate homes.
This video was supported by the Heising-Simons Foundation, which focuses on unlocking knowledge, opportunity, and possibilities. To learn more about the Foundation and its Science program, which supports fundamental research primarily in the physical sciences, visit www.heisingsimons.org.
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This version maintains the original content while ensuring clarity and professionalism.
Foram – A type of single-celled organism found in the ocean, known for having a shell made of calcium carbonate. – Scientists study foram fossils to learn about past ocean conditions.
Shell – A hard, protective outer layer created by an animal, often made of calcium carbonate, like those of mollusks and some microorganisms. – The shell of a sea turtle helps protect it from predators.
Ice – Frozen water, a solid state of water that forms when temperatures drop below freezing. – Glaciers are large masses of ice that slowly move over land.
Oxygen – A chemical element that is essential for most life forms on Earth, used in respiration and found in the atmosphere and water. – Fish extract oxygen from the water through their gills.
Seawater – Water from the sea or ocean that contains dissolved salts and minerals. – The salinity of seawater affects the types of organisms that can live in it.
Temperature – A measure of how hot or cold something is, which can affect the living conditions for organisms. – The temperature of ocean water influences the climate of nearby coastal areas.
Climate – The long-term pattern of weather in a particular area, including temperature, precipitation, and wind. – Changes in climate can lead to shifts in ecosystems and habitats.
Sediment – Particles of rock, soil, and organic material that settle at the bottom of a body of water. – Sediment layers in a lake can provide clues about past environmental conditions.
Marine – Related to the sea or ocean, especially in terms of ecosystems and organisms. – Coral reefs are diverse marine ecosystems that support a wide variety of life.
Calcium – A chemical element that is important for the formation of bones and shells in living organisms. – Many marine animals use calcium to build their shells and skeletons.
