Water in Earth’s Processes Study Guide Our test will be December 17, 18, or 19, depending on your class period.

“The Blue Planet” 70% of the Earth’s surface is covered in water.

97% of the water on Earth is salt water.

The oceans’ salinity is too high for humans to consume. The salt in the ocean and seas comes from weathering and erosion of rocks. Sea water has a higher concentration of sodium chloride, NaCl (salt). When fresh water pours into the ocean, the salinity (salt content) stays the same because water continually evaporates out of the ocean.

3% of the water on Earth is fresh water.

Ice caps and glaciers make up 2%. The greatest amount of fresh water on Earth is found in glaciers and polar ice caps.

Groundwater makes up .9%.

Rivers, lakes, and swamps make up .1%. Lake Superior Amazon River Largest freshwater body on Earth Largest carrier of freshwater to the ocean

If new wells are created due to a population increase, the water table would drop.

Threats to Our Water Supply 1. Pollution – fertilizers, pesticides, sediments, trash, oil/gasoline, chemicals pollute groundwater 2. Drought – long periods of little or no rain can affect water supply and farming 3. Overuse- humans are consuming too much of freshwater supply

HUMANS ARE USING TOO MUCH WATER. *The average person uses between 40 to 80 gallons of water per day. *An average family of 4 uses between 160 to 320 gallons of water per day.

The Water Cycle The water cycle is powered by heat from the Sun. It is the continuous movement of water from the ocean to the atmosphere to the land and back to the ocean.

Heat energy from the sun causes evaporation and transpiration. Evaporation is when liquid water changes into water vapor and rises.

Transpiration Transpiration is evaporation of water through plant leaves. If you were to hang a wet swimsuit to dry, the heat of the sun, the speed of the wind, and the amount of water vapor in the air (humidity) would affect the evaporation/dry time.

Condensation Condensation is when water vapor cools and changes into water droplets that cling to dust particles and form clouds in the atmosphere.

Precipitation Precipitation is rain, snow, sleet, or hail that falls from clouds onto the Earth’s land and oceans.

Types of Frozen Precipitation (determined by air temperature) 1. Snow- water vapor turns directly to a solid 2. Sleet- rain drops pass through a layer of freezing temperature near Earth’s surface 3. Hail- water droplets freeze around a small ice crystal

Snow Sleet Hail

Where does precipitation go? Percolation is the downward movement of water through pores and other spaces in soil due to gravity. Runoff is precipitation that flows over land into streams and rivers. Accumulation is when water gathers in large quantities such as rivers, lakes, oceans, glaciers, ice caps, and aquifers (geological formation containing groundwater.)

Winds blowing constantly Ocean Motion 3 types Currents Waves Tides “Rivers in oceans” 2 types Surface Currents Deep Currents Caused by Caused by Caused by Winds blowing constantly Changes in temperature and salinity Winds blowing occasionally Moon’s gravitational pull on Earth upwelling

Waves Waves are mostly caused by wind, which is caused by energy from the Sun.

Sometimes undersea earthquakes or landslides can cause waves. http://www.embc.gov.bc.ca/em/tsunamis/causes_2.htm Tsunami animation

Currents A current is a movement of ocean water that forms a regular pattern.

Currents There are two types of currents: surface currents and deep currents. Currents can best be described as “rivers in the ocean.” Just keep swimming! http://www.youtube.com/watch?v=JpV7NIJTxD0

Surface Currents Surface currents are horizontal and occur within the top several hundred meters of the ocean. Surface ocean currents are caused by global winds, the Coriolis Effect, and continental deflections.

Global winds cause surface currents. Global winds are constant and unchanging. They are NOT the same as local winds that change daily. Examine global surface currents.

The Coriolis Effect steers surface currents. Observe an animation of the Coriolis effect over Earth's surface. Paper and pencil demonstration

Continental deflections steer surface currents. When a current runs into a continent, what does it have to do? It has to deflect, or go a different way.

Surface currents affect climate. How do you think the Gulf Stream affects the United Kingdom’s climate? Look at Hopedale in Canada and Stornaway in Scotland, each at about the same distance from the Equator. Which has a colder climate? Why?

Deep Currents (also known as density currents) Density differences due to salinity and temperature create deep currents, but not ocean waves. Currents are pretty cool. http://www.youtube.com/watch?v=JQZ3QkaWWqA

Density of Water Think about those molecules. More salt (higher salinity), more dense water, sinks Less salt (lower salinity), less dense water, rises Cooler water, more dense Warmer water, less dense Sinks! Rises!

Relating Cause and Effect Global Winds Surface currents Differences in ocean water density due to salinity and temperature Deep currents

Great Ocean Conveyor Belt

Tides Tides are the daily rise and fall of water levels that are caused by gravity due to the moon and sun. Water rises slowly and covers the shore twice a day then slowly falls back. Animation: http://oceanservice.noaa.gov/education/tutorial_tides/media/supp_tide05.html

High Tide Low Tide

Spring Tide and Neap Tide High spring tides are caused by an alignment of the Earth, moon, and sun. Neap tides have the smallest daily tidal change and occur when the sun and moon are at right angles relative to the Earth. The gravitational forces of the sun and moon work against each other. Animation: http://oceanservice.noaa.gov/education/kits/tides/media/sup p_tide06a.html

Spring and Neap Tides

Spring and Neap Tides Song http://www.youtube.com/watch?v=KFYf_it461s&list=UUJjstNDkwktHyvUdtcBfb2g

Ocean Topography Review Draw and label the parts of the ocean floor. Continental Shelf Seamount (Island if above sea level) Abyssal Plain Mid-Ocean Ridge Continental Slope Rift Valley Deep-sea Trench

Ocean Topography Review

Match the number to the topographical feature. 1. Steeply sloping edge of continental shelf that drops to the ocean basin 2. Volcano that does NOT rise above sea level 3. Mountain that rises ABOVE sea level 4. Relatively flat part of continent covered by sea water 5. Deepest part of the ocean, a deep ocean trough 6. Flat, almost level, area of the ocean basin, covered with layers of sediments 7. Underwater mountain chain where 2 plates diverge 8. A break in the Earth’s crust where 2 plates diverge.  

Ocean Topography Review Sonar is used to measure the depth of the ocean floor. As you go deeper into the ocean, the pressure increases; therefore, the pressure would be the greatest in a trench. Algae is found above the continental shelf since it needs sunlight to survive. Mid-ocean ridges are underwater mountain chains near active volcanoes.

Remember those mid-ocean ridges? https://www.youtube.com/watch?v=sgDM6m0lUGY&list=PLK5QnX_5Gp3Wfz4pMZOVMLd9ujDIzfAGb&index=1 Like the seams of a baseball…

Resources and Energy Recycling – reusing waste or scrap materials to help people save natural resources. One renewable resource from the ocean is wave energy.

Hydroelectric Energy Hydroelectric energy is energy created by the movement of falling water.