Water on Earth Water Planet 6E3AC Water on Earth

6SE3: Explain the role water plays in Earth processes. a. Determine where Earth's water is located on its surface, and create a circle/pie graph to illustrate the relative proportion of water in each location.

Stem Scopes: Engage Water Description Use a potato to demonstrate the percentage of the entire water distribution on Earth. The potato represents Earth. How much of the world is water? If 71% of the world is covered in water, then 29% is land. Cut 29% out of the potato. This portion is discarded or put away to the side to represent the land.

Use the rest of the potato to represent the total amount of water on Earth.  Which percentage of water on Earth is ocean water? According to the graph, 97% of the water on Earth is found in the ocean, which is salt water. The teacher estimates and cuts out 97% of the remaining potato and discards it, only saving a small slice. Students should see that the small amount remaining of the potato represents freshwater.

Water On Earth Graph

With the tiny piece of potato remaining, explain that 70% represents glaciers, 30% groundwater, and only 1% the freshwater that is available for human consumption. The teacher should peel the skin off the tiny piece of potato remaining to represent the amount of freshwater available for us to consume. (The teacher may want to compare the remaining piece of freshwater to the whole potato.)

Water on Earth Students will create their own graph that shows the distribution of water on Earth. Using Student Worksheet Teacher prompt: What are your thoughts on Earth’s water supply? There is a lot of water on Earth, but most of it is not available for us to drink. Maybe we can find a way to make ocean water safe to drink. There is way more salt water than freshwater.

Water on Earth Pie Graph LAND 29% WATER 71%

Water on Earth StemScope: Water on Earth TedEd Where did Earth’s water come from? Lesson: http://ed.ted.com/lessons/where-did-earth- s-water-come-from-zachary-metz#digdeeper USGS Water on Earth - https://water.usgs.gov/edu/earthwherewater.html What would happen if all of the water melted? https://www.youtube.com/watch?v=b6CPsGanO_U

Where is water found on Earth: Scavenger Hunt Scavenger hunt Teacher Scavenger Hunt kids

Key Concept 1: Water covers 71% of Earth’s surface Key Concept 1: Water covers 71% of Earth’s surface. Of that, 97% is salt water, and only 3% is fresh water

Key Concept 2: Fresh water comes from sources such as rain, streams, rivers, underground water, glaciers, and most lakes. Show me the water Video

Only 3% of all water is fresh water (contains only traces of salt), but most fresh water is locked up in the frozen polar ice caps. Only water from rain, streams, rivers, melting glaciers (frozen masses of ice), underground, and most lakes is considered fresh water. Not all fresh water is suitable for drinking, due to toxic chemicals, aquatic microorganisms, or harmful minerals. It must be decontaminated in water treatment plants. Glaciers and polar ice contain the greatest reserves of freshwater. As the Earth warms and glaciers melt, this percentage could change as the fresh water drains into the oceans. Groundwater is water that has percolated through the soil and into rock layers of Earth. Natural springs are the result of groundwater rising back to the surface. Rivers, lakes, swamps, marshes, bogs, streams, bayous, and ponds are the smallest concentration of fresh water. These are typically humans’ sole sources of water for living, and they also tend to be greatly affected by pollution.

Key Concept 3: Salt water comes from sources such as oceans and saltwater marshes and some lakes.

There are four oceans divided by continental land masses There are four oceans divided by continental land masses. The largest is the Pacific, followed by the Atlantic, Indian, and Arctic. However, because none of the oceans are isolated from any of the others, together they can be thought of as Earth’s one major ocean. Deep ocean currents connect all oceans and circulate the water completely once every thousand or so years. 

Key Concept 4: Ocean floor topography starts with the continental margin, made up of the continental shelf and the continental slope, and subsequently the ocean basin floor.

Continental Shelf: The outer continental shelf starts as the water begins. This zone is shallow, slopes progressively, and holds water that is not very deep. The continental shelf width changes significantly depending on the locality, ranging from a few kilometers to hundreds of kilometers. Much of the shelves were exposed during glacial periods. Some 18,000 years ago, at the peak of the most recent ice age, much of Earth’s water was frozen in huge glaciers. The sea level dropped, exposing continental shelves, during a time in which the sea levels were perhaps 100 meters lower than they are today.

The Ocean Basin: The next major ocean bottom feature is the ocean floor with its flat areas of deep sediments called the abyssal plains (shown in bright blue on the map), deep underwater trenches, island arcs, and mountains (mid-ocean ridges).

Math of water Water Studies - The Math of Sufficient Fresh Water Read: Orme Tenn has run out of water

Math Connection from stem scope The majority of Earth’s surface is covered with water. Most of Earth’s water is salt water. Only a small amount is fresh water, including water found in many lakes, rivers, and underground streams, brooks and basins, and in the form of ice. Earth has an estimated 338,168,194 cubic miles of water. However, not all of that water is drinkable. Use the following formula to figure out just how much water is available for the human population to drink:

Percent of Water Type × Total Amount of Water=Amount of Water Type Water Source Percent of Freshwater Percent of Total Water Oceans, seas, and bays — 96.5 Ice caps, glaciers, and permanent snow 68.7 1.74 Ground water 1.69 Freshwater 30.1 0.76 Saline 0.93 Soil moisture 0.05 0.001 Ground ice and permafrost 0.86 0.022 Lakes 0.013 Fresh 0.26 0.007 0.006 Atmosphere 0.04 Swamp water 0.03 0.0008 Rivers 0.0002 Biological water 0.003 0.0001

A large body of salt water; cover most of Earth’s surface Ocean A large body of salt water; cover most of Earth’s surface

Glacier A large, slow-moving, long-lasting accumulation of snow and ice that develops on land

A body of fresh water that flows continuously towards the ocean River A body of fresh water that flows continuously towards the ocean

A large body of water surrounded by land Lake A large body of water surrounded by land

Fresh water Water found in rivers, lakes, glaciers, ice sheets, and underground that contains low concentrations of salt

Water found in oceans (and few lakes) that contains 3-4% salt Salt water Water found in oceans (and few lakes) that contains 3-4% salt

Topography A description of land surface area with reference to variation in elevation

Continental shelf Area of seabed around a large landmass where the sea is relatively shallow compared with the open ocean

The slope between the continental shelf and the ocean floor Continental slope The slope between the continental shelf and the ocean floor

Abyssal plain Underwater plain on the deep ocean floor, usually found at depths between 3000 and 6000 m

Trench Deep and narrow depressions in the seafloor where the subducted plate moves into the asthenosphere