Why is the Earth often called the Water Planet?
About 70% of the earth is covered by water
What is the water cycle?
Cycle where water on Earth is continuously being recycled above, across, & through ecosystems
What drives the water cycle?
The sun
Where is most of the Earth’s water?
Oceans
Evaporation
Process of liquid water changing into water vapor?
Condensation
Process of water vapor changing into liquid water, water vapor joins other gases in the atmosphere and cools as it rises high into the air. When it cools enough, it condenses and forms clouds.
Precipitation
Solid or liquid water falls from air to earth (rain, sleet, hail, snow). Drops of condensed water in clouds collide and get larger. When drops are too heavy to be held up by air currents, they fall to the Earth.
Groundwater
Water in gaps and pores in rocks below Earth’s surface, can collect in underground lakes called aquifers
What is fresh water?
Water with very low salt content
How much of the water on Earth is fresh water?
3%
How much is salt water?
97%
Why is over 3/4 of Earth’s water impossible to use?
It’s frozen
Where does almost all of the usable fresh water on Earth come from?
Groundwater
Continental shelf
Gradually sloping part of the ocean floor made of continental crust
Continental slope
Birder between continental crust and oceanic crust
Abyssal plain
Vast, flat floor of the ocean that covers almost 1/2 of Earth’s surface
Mid-ocean ridges
Mountain ranges on the ocean floor
How do oceans affect climate?
Help keep land cool during summer and warm during winter. Differences in water and land temperature cause winds to form.
Currents
Steady, stream-like movements of the ocean caused by wind, gravity, heat from the sun, and Earth’s rotation
Surface currents
Easy to predict, produced by global winds that move in patterns
How can currents cause warm climates to cool down?
Cool water currents form near poles and flow toward the equator
What are the resources of the ocean?
Water, saltwater organisms, no food products like pearls, sea salt, petroleum, sand
Water
Salt must be removed in desalination plants
Saltwater organisms
Shrimp, lobster, seaweed, etc
Sea salt
Used for cooking, agriculture, preserving, meat,refining metals, etc
How are ocean zones determined?
By depth of the water
What happens as ocean depth increases?
Less light
Intertidal zone
Area of ocean between levels of high tide and low tide, shallowest and brightest zone where environment is always changing
How do intertidal organisms handle environment changes?
Some bury themselves in sand, some hide under rock, others close shells tightly, trapping water inside.
Near-shore zone
Includes most of the ocean over the continental shelf, relatively shallow and gets a lot of sunlight
Open-ocean zone
Includes most water over the continental slope and abyssal plain; cold, deep, and dark; 90% of the ocean
Coral reefs
Large delicate structures built by living coral in shallow, sunlit water in the near-shore zone
How do coral reefs form?
Use minerals dissolved in ocean water to form hard skeletons. Living corals attach to skeletons of dead coral to slowly form a reef
What do reefs provide?
Underwater surfaces easily reached by sunlight and shelter for many kinds of animals
Deep ocean vents
Recently discovered ecosystem deep in ocean that gets energy from chemical reactions instead of the sun
What chemicals make the energy in deep ocean vents.
Volcanic vents spew hot water containing sulfur and iron chemicals. Bacteria uses these to store energy and are depended on by rest of ecosystem for energy