Water on Land. The Hydrosphere. Hydrosphere. The Earth Consists of Overlapping Layers:

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1 The Hydrosphere Earth and Space Continued The Earth Consists of Overlapping Layers: 1. Hydrosphere + Cryosphere 2. Atmosphere 3. Biosphere 4. Lithosphere Hydrosphere The is earth s outer layer of water. Water can be found in many forms on earth: Salt water in oceans Fresh water on land Brackish water in oceans à brackish water is a mix of fresh and salt water Frozen as ice in: 1) Ice Floes / Sea Ice (Ice in water) 2) Glaciers/Ice Caps (Ice on land) Water on Land

2 Catchment Areas AKA Watersheds A Catchment Area or Watershed is an area on land where all inland water (such as ) meet to drain into the same larger body of water ( ) Simple Definition: A catchment area is a territory of land surrounding a waterway Catchment Areas AKA Watersheds Factors affecting the flow of water in the watershed 5 Factors affecting the flow of water in the watershed: 1) Topography : the shape, slope and terrain of the area 2) Geology: the type, depth and structure of rock, ability of the soil to absorb the moisture 3) Climate: precipitation, temperature and winds 4) Vegetation: density and diversity of plant life. 5) Human Activity: Agricultural, industrial and urban developments 1) : the shape, slope and terrain of the area Shape Terrain Slope For Example: If there is a mountain, then the water will flow down one side or the other

3 Water has been added to both Sand and Rocks. What do you observe? Factors affecting the flow of water in the watershed 2) : the type, depth and structure of rock, ability of the soil to absorb the moisture For Example: Sand can absorb moisture but gravel rock cannot, this means that water will drain right through large rocks but will get partly absorbed into sand and fine particles if flowing slowly. Sand Gravel Factors affecting the flow of water in the watershed 3) : precipitation (rain/snow), temperature and winds Excessive amount of precipitation can increase the amount of water / cause flooding of areas Amount of sun and wind can affect the amount of evaporation of water occurring. Given the image below, what impact do you think trees have on the ability of water to flow over an area?

4 Factors affecting the flow of water in the watershed With the person next to you, discuss how the flow of water could be affected by the following Human Activities: 4) : density and diversity of plant life. à Plants absorb water and keep water in the soil around them. This means that more water will stay in the are than if there were to plants. Example: If an area has lots of trees, then their roots will keep soil and rocks in place. This allows for resistance to erosion (leaving of soil) when water flows over the land. A) Agricultural Fields AND B) Industrial (such as mining) and Urban Developments Factors affecting the flow of water in the watershed Pollution 5) Human Activity: Agricultural, industrial and urban developments Agricultural: Polluting upriver, can have devastating effects downstream in the watershed. Industrial and Urban Developments: Video For Reference:

5 The Oceans The Oceans Oceans are divided by the continents: Pacific Ocean, Atlantic Ocean, Indian Ocean, Arctic Ocean and the Antarctic (Southern) Ocean Oceans contain 97% of the The Oceans The Oceans Ocean waters are moved by that carry them all around the world à the water in oceans is constantly circulating. Water Temperature and Salinity (the amount of salt in the ocean) are important characteristics of the ocean and determine current movement

6 The Thermohaline Circulation AKA Oceanic Circulation Factors that affect the Thermohaline Circulation Thermo means Temperature Haline means Salt Ocean circulations are determined by the temperature (thermo) and amount of salt (haline) in the water in different areas! 1) Temperature 2) Salinity ß à Density of ocean water 3) Winds 4) Earth s Rotation Factors that affect the Thermohaline Circulation 1) is affected by the following: a. Depth à the deeper the water is, the less sunlight there is to warm the water, therefore the water is colder b. Seasons à less direct sunlight in winter c. Latitude à water near the equator is warmer than water near the poles Temperature of the Oceans In Words As you decrease in depth (as you go deeper in the ocean) the temperature of the water gets colder. This make sense because the sun warms up the water, so the closer to the surface the water is, the warmer the water is.

7 Factors that affect the Thermohaline Circulation 2) (amount of salt dissolved in a liquid) is affected by: Factors that affect the Thermohaline Circulation 3) : Surface ocean currents are primarily affected by wind patterns. Trade winds (strong seasonal winds) can push water along the top of the ocean and aid in the formation of surface currents. a. Heat and drought à when there is a lot of heat, the water will evaporate, leaving more salts in the water (raising the concentration of salts) b. Freezing Sea water à salt is forced out of the ice crystals when sea ice forms, causing the surrounding water to become saltier b. Melting pack ice and glaciers à dilute the seawater and reduce the salt content Factors that affect the Thermohaline Circulation 4) : You can see the ocean currents deflecting due to Earth s rotation in the Northern and Southern Hemispheres.

8 Oceanic Circulation Density and Subsurface Currents An is the movement of seawater in a certain direction 2 main types of ocean currents: 1. surface currents: mostly wind driven, they move horizontally 2. subsurface currents: mostly due to variations in density Ocean circulation is the combined effect of all the currents that move across the ocean Subsurface currents: mostly due to variations in density. The the water, the more it is, so it sinks below the less dense water and moves along the ocean floor. Density differences are also caused by differences in salinity. à the more salt there is in the water the more dense it is. Density of Ocean Water Less Dense More Dense Salinity (Amount of Salt) Temperature

9 Thermohaline Circulation Thermohaline circulation is a huge conveyor belt formed by surface and subsurface currents that moves water all around the world. It helps to regulate the Earth s climate by moving heat around the world Ocean Conveyor Belt - Animation The Cryosphere à All of the frozen Ice on Earth

10 2 Types of Frozen Water: 1) (Ice Floes) : Composed of seawater that has frozen in the winter Expands during winter to cover about 5% of the northern oceans and 8% of the southern oceans Is important to global ocean circulation and climate patterns Pack ice itself is now endangered because of global warming The Global Effects of Melting Pack Ice 1) Melting Pack Ice Increases the Amount of Water in the surrounding area: Changes in freshwater inputs to the North Atlantic may alter the global ocean currents with far-reaching effects on the global climate. 2) The amount of solar energy absorbed by Arctic seas increases with large areas of open water. à This causes even warmer seas. 3) Warming temperatures are leading to the release of methane a powerful greenhouse gas from the seabed and melting tundra, wetlands and lakes in the Arctic. 4) These changes could potentially impact global weather patterns and ocean circulation. 2 Types of Frozen Water: 2) /icebergs/ice shelves: Frozen fresh water on land Contains 79% of the world s fresh water reserves Melting ice caps/glaciers can cause: a raise sea levels, a loss of fresh water reserves, cause a decrease in salinity and density of the water in oceans

11 What if all the ice melted? What happens to sea levels if Sea Ice melts? Sea Level Rise - Why do we care if the oceans levels rise? The above website allows you to pay with the levels of sea level rise, to see what global effects that amount of water would have. What happens to sea levels if Glaciers melt? For reference: