The Hydrosphere

Unit Review Sheet

Facts and Definitions

Lesson 1: The Hydrosphere

• A solution is made when two or more substances are mixed together.
• Mass measures how much matter is in an object, and volume is the amount of space that an object takes up
• Mass is different from weight. Mass measures how much matter is in an object, while weight is a measurement of how heavy something feels
• The density of a material is its mass per unit volume. Density is mass divided by volume (D = M/V).
• All substances do not have the same density.
• The density of a solution is influenced by what the solution contains. For example, tap water is less dense than salt water.
• Salinity is a measure of how much salt is in water. Salinity and temperature influence density.
• Density plays a significant role in the movement of the oceans' waters. Variations in density due to variations in temperature and salinity drive a global pattern of interconnected ocean currents.
• The ocean exerts a major influence on weather and climate by absorbing energy from the sun, releasing it over time, and globally redistributing it through ocean currents.
• The complex patterns of the changes and the movement of water in the atmosphere, determined by winds, landforms, and ocean temperatures and currents, are major determinants of local weather patterns.

Lesson 2: Water and Its Characteristics

• Water is made from different types of atoms to form molecules.
• Water molecules are moving about and are constantly in contact with other water molecules.
• Cohesion is the attraction between two molecules of the same type; adhesion is the attraction between two molecules of different types.
• Polarity is the presence of two different charges (positive and negative) on an object.
• The polarity of molecules allows cohesion to occur.
• Surface tension is a property of the surface of a liquid that allows it to resist an external force.
• Surface tension is caused by the cohesion of like molecules and is responsible for many of the behaviors of water.

Lesson 3: Water and Its Distribution

• Groundwater is water contained in the open spaces (pores) found in soil and/or rock.
• An impermeable layer is a layer through which water does not flow or pass (for example, granite).
• A permeable layer is a layer through which water flows or passes easily (for example, limestone).
• The zone of saturation is the zone found in an aquifer that has all the pores filled with water.
• The water table is the top surface of the zone of saturation. It may be above or under ground.
• The zone of aeration is an area of an aquifer where the pores are partially filled with water and partially filled with air.
• Water continually cycles between land, ocean, and atmosphere through evaporation, condensation, precipitation, and downhill flows on land.
• Growth of living organisms like animals and humans and population increases are limited by access to water.

Lesson 4: Marine Ecosystems and Estuaries

• An estuary is a coastal area where freshwater from rivers and streams blends with saltwater from the ocean, creating a partially enclosed water body.
• Thousands of species of birds, mammals, fish, and other wildlife rely on estuarine habitats for living, feeding, and reproducing.
• Biodiversity describes the variety of species found in an ocean ecosystem.
• The integrity of an ecosystem's biodiversity is used as a measure of its health.

Lesson 5: Shaping Waters: Natural Forces and Human Impact

• Sediments are bits of soil, sand, and minerals that get into the water when runoff carries them into lakes, streams, and rivers.
• Erosion is the process where natural forces like water wear away rocks and soil from the Earth's surface.
• Eutrophication is when excess nutrients in water cause rapid algae growth, leading to oxygen depletion and harm to aquatic life.
• Hypoxia is a lack of oxygen.
• Water movements cause weathering and erosion, which change the land's surface features.
• As human populations grow and resource consumption increases, the negative effects on Earth's environment, including those from farming, typically rise—unless activities and technologies are carefully engineered to reduce harm.

Lesson 6: The Water Cycle

• The water cycle is the process where water moves between the air, land, and oceans by changing forms, like turning into vapor, forming clouds, and falling back to Earth as rain or snow.
• Transpiration is the process where water is taken in by plant roots, transported to its leaves, and released back into the atmosphere.
• Pollution is the introduction of harmful waste products, chemicals, and other substances not native to an environment.
• Stewardship is the practice by organizations, communities, and others to plan and manage environmental resources to prevent or lessen the loss of habitat and aid a habitat's recovery.

Lesson 7: Challenges for Earth's Reservoirs

• The biosphere includes all of the ecosystems found in all areas of the Earth.
• Humans depend on Earth's oceans and biosphere for many different resources. Minerals, fresh water, and biosphere resources are limited, and many are not replaceable over human lifetimes.
• Human activities have significantly altered the biosphere, sometimes damaging or destroying natural habitats and causing the extinction of other species.
• Abiotic elements are the nonliving components of the biosphere.
• Biotic elements are the living components of the biosphere.
• An inquiry is any process that has the aim of deepening knowledge, resolving doubt, or solving a problem.

Lesson 8: Water Quality

• Water quality is a measure of the condition of water relative to the requirements of the organisms it contains or the organisms that use it as a resource.
• Ecosystems are dynamic in nature; disruptions to any physical or biological component can lead to shifts in all its populations.
• Steady state is a characteristic of a system in which properties are unchanging over time.
• Oxygen is a key factor in the chemistry and biology of coastal waters, and its concentration indicates water quality, with higher levels supporting thriving ecosystems.
• Nitrogen is essential for photosynthesis in marine plants, but it must first be converted into usable forms like nitrate or ammonia before plants can absorb it.

Lesson 9: Water Quality, Algal Blooms, and Pollution Solutions

• Pollutants like chemicals, oil spills, and plastic waste can seriously harm our water, air, and land.
• Algal bloom is a rapid increase in the algae population of an area that is the result of chemical pollution.
• Conservation is important for managing natural resources like water to prevent pollution and protect ecosystems.
• Sustainable practices, such as recycling and eco-friendly farming, help meet current needs without damaging the environment.
• Environmental laws, like the Clean Water Act, are designed to reduce pollution and safeguard our natural resources.

Lesson 10: Food Webs and Food Chains

• A food chain is a representation of the feeding relationships among specific organisms in an ecological community.
• A food web is a model that demonstrates how matter and energy are transferred between prodocers, consumers, and decomposers as the three groups interact within an ecosystem.
• Terrestrial means related to land.
• Producers are the organisms that use sunlight to make food necessary for survival.
• Primary, secondary, and tertiary consumers are organisms that rely on other organisms for energy and are not capable of making their own food.
• Primary consumers (such as cows, deer, and clams) consume producers like grass and algae.
• Secondary consumers (such as bears, coyotes, some fish) consume primary consumers.
• Tertiary consumers (such as sharks, killer whales, humans) consume whatever they need.
• Decomposers (such as bacteria, marine worms, fungi, certain species of crabs, sea cucumbers) recycle nutrients from dead plant or animal matter back to the water in aquatic environments.

Final Project: Steward of the Hydrosphere

• A steward is an official who supervises or helps to manage.
• Sustainability describes how biological systems remain diverse and productive over time. For resources, it refers to the availability of amounts necessary for normal function.