Grade 8 Science: Unit E - Section 1 and 2

what else can earth be called?

blue planet or water planet.

How much drinking water on Earth is available for humans to drink?

0.003%

Where is most of the freshwater on Earth?

ice in Antarctica and the arctic.

What portion of the Earth's surface is covered with water?

74%

potable water

water that is safe to drink

reservoir

tanks that store liquids.

Where is most of the freshwater on Earth? Is it readily available for humans to use? Why or why not? How much of all the water on Earth is available for humans to drink?

-Ice in antarctica and the arctic
-Probably not because there is sometimes bacteria and germs in ice.
-0.003%

Describe the breakdown of all the water on the Earth using percents (%). If all the water on Earth is represented by a 1000 L tank, how many milliliters (mL) of that would be available for humans to drink (that is, potable water)?

30 mL is drinkable.

what percent of earths water is: fresh water

3%

what percent of earths water is: salt water

97%

what percent of earths water is: rivers, lakes and wetlands

1%

what percent of earths water is: groundwater

22%

what percent of earths water is: ice

77%

water quality

how pure the water is.

Salinity

A measure of the amount of dissolved salts in a given amount of liquid

hard water

water containing a lot of calcium and magnesium

distillation

how to separate solutions using boiling water and condensation.

reverse osmosis

movement of water through a membrane from a low water concentration to a high water concentration

items drinking water is tested for:

-taste and odour
-cloudiness and colour
-toxic substances and other pollutants
-bacteria
-hardness or mineral content
-acid in the water (pH)
-dissolved oxygen
-solids and floating materials
-dissolved solids

How can you determine water quality?

by measuring how much substances beside the water are inside of the water.

where is most fresh water locked up in?

ice and in the ground

Hard water contains a high concentration of which minerals? How might you be able to tell if you have hard water? What do you think soft water is?

-Calcium and magnesium
-When hand soap doesn't lather very much.
-More clear and less calcium and magnesium

How does the salinity of freshwater and saltwater compare?

saltwater has more salinity (average of 3.5% and contains golds and silver too) then freshwater.

Where do most cities and towns get their drinking water from? How do they ensure this water is at a level of quality that is safe for human use?

lakes, rivers, waterfalls and oceans. They test the water and put it through procedures to turn it into freshwater.

Water is filtered and treated with chemicals, such as ______________, to kill any dangerous organisms

chlorine

saltwater's average salinity is

3.5%

Describe the two procedures that can be used to produce fresh water from salt water.

Distillation, the solution is boiled so the water evaporates and the salts stay inside the beaker, while the evaporated water goes through a tube and cools down and condenses causing it to return back to water.

Reverse osmosis, salt water is compressed being forced through a semipermeable membrane. The holes are too small for the salts to go through causing them to be left behind while freshwater is on the other side.

waves

movement of the surface of water

tides

rising and falling of large bodies of water

What is the difference between a wave and tides?

waves is the difference of the movement pattern while tides are when the water falls or rises in level.

What causes waves?

mostly wind

How does the water itself move in a wave? How can a rope be used to model this behaviour?

- It moves a small distance in tiny circles.
- The waves move through the rope without the rope going anywhere

What impact does waves have on the shoreline?

they crash into the shore since it's shallower and it changes their shape.

We usually think of waves on lakes and oceans. Can rivers have waves? If so, what causes them?

i think yes, and it would most likely be from wind but not as big and dangerous as the ocean.

what causes tides?

the gravitational pull of the moon

What's the difference between high tide and low tide?

high tide: the water is the highest level (rising)
low tide: water is at the lowest level (falling)

Small waves that move gently on the shore are likely to

deposit sand or other materials near the shore

Which of the following statements is incorrect?

A wave can travel thousands of kilometres, and it carries the water over this distance as well

Stream Characteristics

volume/rate of flow, slope, shape of stream, amount of dissolved material, width, depth, amount of vegetation, etc.

sediments

matter that settles to a bottom of the liquid.

Continental Divide

watershed of a continent.

What is the difference between deposition and erosion?

erosions is fading away when deposition is laying down or deposition of rocks.

What does a river's sediment load refer to? What does it mean for something to be water-borne?

-How many rocks/minerals have dissolved in the water
-Carrier by water

What happens to a river's sediment load as the speed of its current slows down?

it decreases

What can chemical weathering cause?

the water sits on the rocks while it slowly erodes them.

What determines the direction that a watershed drains in? What is this high land called?

-The location of the highest continent
-Continental divide.

Where is the Continental Divide in North America located? How does it impact water flow in Canada?

-Rocky mountains
-The rivers flow into the pacfic, atlantic and arctic oceans.

Stream characteristics include the

rate of water flow and the slope of the stream's bed

A river's sediment load is the amount of

water-borne materials it can carry

the floodplain

The flat land on either side of the river that becomes covered with water whenever the river overflows its banks.

Which of the following is an example of chemical weathering?

Edmonton crews spray a salt-water solution to prevent icy streets in the winter time, causing cracks and holes in the asphalt.

Major North American watersheds are determined by the Continental Divide, which is located in the

rocky mountains

Describe the appearance of each of these landforms and how they are formed: eskers

A long ridge of gravel and other sediment, typically having a winding course
When parts of the glacier melt it releases sand and gravel from it which are then deposited by the meltwater in the matter of a winding river.

Describe the appearance of each of these landforms and how they are formed: moraines

A mass of rocks and sediment carried down and deposited by a glacier
They form from rocks and gravel that build up along the sides of the end of a glacier. As it melts large deposits form.

Describe the appearance of each of these landforms and how they are formed: drumlins

Small hills with teardrop shape
When a glacier moves over moraine that had formed earlier, the tip of the hills point where the glacier was moving.

Describe the appearance of each of these landforms and how they are formed: kettle lakes

Small round lake.
When large chunks of the ice was left by a glacier and melted.

How does climate affect the movement of glaciers?

when it's cold the glacier doesn't melt lots and builds up on snow causing it to move forward. When it's warm there is more melting causing it to retreat or melt back leaving the soil and rocks.

What effects does a glacier moving have on land?

it picks up the rocks as it moves causing the land to reshape.

What are valley glaciers?

they flow down through the high valleys between mountain peaks.

Describe continental glaciers.

glaciers that cover a vast area of land.

How do ridges form? What are ridges a sign of?

when plates collide and tsunamis and earthquakes.

Geological features on the ocean floor are a result of the continental plates moving. Where the plates are moving away from each other you will find

mid-ocean ridges

How do trenches form?

the plates slide apart.

What is a seamount? What may a seamount eventually become?

underwater volcano and eventually it can become a volcanic island.

What are continental shelves?

the shallow areas around the continent.

Describe the movement of the plates that make up the Earth's lithosphere.

they move slowly towards each other or farther apart.

What is the lithosphere made of?

made of rocks broken into huge plates.

glaciers

huge, slow moving sheets of ice

valley glaciers

Continental glaciers, or icecaps, cover large areas of land, forming the coldest regions on the Earth. Glaciers can also form high up in mountain ranges, where snow and ice build up over long periods of time.

Mid- ocean ridge

Geological features on the ocean floor are a result of the continental plates moving. Where the plates are moving away from each other.

eskers

Glaciers gouge huge areas of the land and then reshape the land by the materials they collect and deposit. Some of the features include long, narrow hills in the pattern of a winding river.

Drumlin

Glaciers gouge huge areas of the land and then reshape the land by the materials they collect and deposit. Some of the features include rounded hills that form at the sides or end of the glacier.

climate

Overall weather in an area over a long period of time

currents

are streams of water that move within a larger body of water

How do large bodies of water impact climate? Why does this occur?

Large bodies of water can affect climate by moderating temperatures and increasing humidity in nearby areas, due to their ability to absorb and release heat more slowly than land.

What is the difference between wind that blows over a warm ocean current compared to a cold ocean current?

as the wind cools down the water becomes more dense and can become so cold it turns into ice. If it's warm wind it will heat up the water causing it to be less dense.

What geological evidence do we have here in Alberta that glaciers once covered this province?

scratches on the bedrock show how th glacier moved.

What causes currents?

wind, temperature in water, salt differences and earth rotation.

How are currents different from waves? What causes surface currents?

when the water is moving, waves sare just the energy moving throughout the water. Surface currents are from the wind; the wind is just moving the surface of the water.

How does the temperature of an ocean current affect the amount of precipitation?

if the water is coming from the equator it brings warm water, which is able to rise and create more rain. But if the water comes from the north or south poles it creates less rain because it takes longer for the water to warm and rise up.

Large bodies of water influence the climate of a particular area. The main effect that they have is to

prevent extremes in temperature

Which of the following statements about water is incorrect?

Water has a lower heat capacity than most other substances.

Currents coming from the Arctic region like the Labrador Current carry cold air, and that is partly what can account for Labrador's cold climate. Scotland gets warm air from the North Atlantic Current, which comes from

near the equator

Which of the following statements about ocean currents and precipitation is correct?

Wind blowing over a warm ocean current will carry moisture.

Describe how a wave forms in a lake. Explain what would happen to the speed and direction of a small boat when a wave passes underneath it.

Waves form when winds cause changes in patterns that move along the lake's surface. The speed and direction of a boat will not change when waves pass under them. The boat will simply rise and fall as the wave passes underneath.

Why do many inland waterways have speed limits for boats?

Inland waterways have set speed limits for boats to help prevent the erosion problems on their lakes and rivers. The "wash" or water displacement from boats can damage and erode the shorelines of lakes, rivers, and streams. The faster the boat moves, the greater the water displacement produced and the greater the possibility of damage by erosion.

When camping in the mountains near the border between Alberta and British Columbia, you noticed one stream flowing west and the other flowing east. What is the area or geological
feature called where you are camping? Where will the water in these rivers eventually end up?

You would be camping on the Continental Divide, an area where streams begin their journey to the Pacific Ocean or to Hudson's Bay.

How do caves form?

Caves form when slightly acidic water flows through cracks. As the water erodes the limestone, large holes form and these eventually become caves.

Why do hot springs have more minerals deposited around them than cold springs do?

When the water in hot springs reaches the surface it cools. Since hot water can dissolve more minerals than colder water, some of the minerals precipitate out of the solution and form mineral deposits. Springs with hotter water carry more minerals and therefore when they cool produce larger deposits.

rounded mountains

When these mountains formed hundreds of millions of years ago, they had tall sharp peaks like the Rocky Mountains. Repeated glaciation has worn them down to the rounded hills we see today.

watershed

An area of land that catches and drains water into a common body of water, like a river or lake. The boundary between two adjacent watersheds is called a divide, and it separates the water flow in one direction from the water flow in another direction.