How can we help?

You can also find more resources in our Help Center.

BC Science 8 -Chapter 10 (Water Systems on Earth)

STUDY
PLAY
Condensation
The change of state from a gas to a liquid
Evaporation
The change of state from a liquid to a gas
Precipitation
The falling to earth of any form of water (rain or snow or hail or sleet or mist)
Freezing point
The temperature at which a liquid changes into a solid
Hydrologist
A person who studies Earth's water systems and helps find solutions to problems of water quality and quantity
Melting
The change in state from a solid to a liquid
Solidification
The change of state from liquid to solid
Sublimation
The change from a solid directly to a gas
Oceanographers
People who study ocean systems specifically
Where is most of the world's fresh water found?
Glaciers
Why is less than one third of fresh water available for use by humans?
Because most of the fresh water on earth is frozen.
What has to happen in order for water to change from one state to another?
Energy has to be added or removed
Deposition
The change of state from a gas directly to a solid
Name the six changes of state
Evaporation
Condensation
Melting
Freezing
Sublimation
Deposition
What is the water cycle?
The movement of water from Earth's surface into the air and back to the surface again.
Where does the salt in
ocean water come from?
As water moves over the ground and rocks, it picks up salt and other substances. The water finds its way into the ocean and all the salt and other substances that were carried by the water also enter the ocean.
Salinity
The amount of salt that is dissolved in water is called salinity.
Why is ocean water more
dense than fresh water?
Ocean water has a higher density than fresh water
because ocean water has more salt in it.
Which has a lower freezing point; ocean water or fresh water?
Ocean water has a lower freezing point than fresh water.
How do volcanoes add salt to the oceans?
Volcanoes on the ocean floor add salt and other substances directly into the water. Volcanoes on land send out substances high into the air. Some of this matter falls right into the ocean. Some of it falls to Earth's surface and is carried to the ocean by water as the water flows over the ground.
Where do dissolved solids in the ocean come from?
Water on the ground, volcanoes on the ocean floor and volcanoes on land.
What percentage of the salt in the ocean is
sodium chloride?
85.6%
How does the mass of 1 L of ocean water and 1 L of fresh water compare?
Ocean water has a greater mass because of the salt in it
How does the density of ocean water and fresh water compare?
Ocean water has a higher density because of the salt in it
How does the salinity of ocean water and fresh water compare?
Ocean water has a higher salinity than fresh water
How do the freezing points of ocean water and fresh water compare?
Ocean water has a lower freezing point than fresh water
Density
Density is the amount of mass in a given volume of a material
Why is ocean water saltier near the Equator?
Close to the equator, the salinity is high because of high rates of evaporation. When the water in the ocean transforms into vapour in the air, it leaves the salt behind.
Why is ocean water saltier near the North and South Poles?
Water is very salty near the North and South Poles because when water freezes and changes into ice, it leaves the salt behind.
Why is ocean water near continents less salty than in the middle of the ocean?
Near continents, the salinity is lower than in the middle parts of the ocean because the fresh water from the rivers empties into the ocean and dilutes the salt water.
Crevasse
A deep crack in a glacier
Glaciers
Glaciers are large blocks or sheets of ice that slowly flow downhill.
Gravity
Force that pulls everything towards the centre of the earth
Ground Water
Water that seeps downward into and through soil or rock
Iceberg
A huge block of floating ice that has broken off a glacier
Run-off
Water from rain or melted snow that flows along Earth's surface into bodies of water.
Aquifer
A layer of rock that is porous and allows water to flow through it
Drainage Basin
An area of land on which precipitation falls and drains into a common river (also called a watershed)
Reservoir
Reservoirs are large human-made or natural lakes that store water until people need it.
What are the two types of glaciers?
Continental and Alpine
How are alpine glaciers different from
continental glaciers?
Alpine, or valley, glaciers are located in mountain areas. Continental glaciers, or ice sheets, are much more massive and cover large areas of land.
Cave
Underground opening that can form when acidic groundwater dissolves limestone
Delta
An area of built-up sediment deposited by a river where the river empties into an ocean or a lake.
Erosion
The process by which wind, water, ice, or gravity transports soil and sediment from one location to another
Karst
An area with many sinkholes
Landslide
A slide of a large mass of dirt and rock down a mountain or cliff
Rapids
A part of a river where the current runs very swiftly.
Striations
Scratches left on rocks and bedrock by glacier movement
Weathering
Weathering is the process of breaking down rock into smaller fragments
Chemical Weathering
The process through which rock is broken down when its mineral react with chemical agents such as oxygen, carbon dioxide, water and acids
Biological Weathering
Physical or chemical weathering caused by plants or animals.
Physical Weathering
The gradual process of breaking down rock physically without changing it composition
Sinkholes
A large circular depression in the ground caused by the collapse of an underground cave
Sediment
Small, solid pieces of material that come from rocks or living things
Most of the world's glaciers are receding.
What does receding mean?
A receding glacier is a glacier that is melting faster than it can slide downstream, this gives the impression that it is going backwards.
Arête
Narrow ridge between two cirques
What are the three main
ways that water shapes
Earth's surface?
Weathering
Erosion
Deposition
How does a cave form?
A cave is formed when acidic ground water starts dissolving carbonate rock and these little gaps become bigger and bigger over thousands of years.
How is a delta formed?
When fast-moving river water enters a body of water such as an ocean or a lake, it slows down and begins to drop sediment it has carried downstream. The pattern created is usually triangular or fan-shaped.
Erratic
Large boulder deposited on the ground by a glacier
Moraine
Ridge of rocky material deposited by a glacier
Esker
Winding ridge of material deposited by a stream running under a glacier
Outwash
Material deposited by water from melting glaciers
Cirque
Bowl-shaped valley at the head of a glacier
Fiord
A narrow inlet of ocean between steep cliffs carved by glaciers
Hanging valley
U-shaped valley cut off by a bigger valley created by a larger glacier
Horn
Pyramid-shaped peak located between three cirques
What percentage of Earth's surface is covered in water?
70% of Earth's surface is covered in water
Stalagmites
Steep mounds or spikes of calcium carbonate that grow up from the floor of a cave.
Stalactites
Thick, icicle-shaped formations hanging from the roofs of caves. Stalactites are formed from dripping mineral-rich water over thousands of years.
What is the relationship between sinkholes and a karst?
Many sinkholes in an area is called karst.
What is the greatest agent of erosion?
Moving water
What happens when Carbon Dioxide gas mixes with rainwater in the atmosphere?
They form a mild acid called carbonic acid. This acid has the ability to dissolve rock.
Acid Rain
Precipitation that is more acidic than normal because of air pollution
True or False? Chemical weathering is greatest in climates with high temperatures, a lot of rainfall and high levels of pollution in the air.
True
True or False? Physical weather is greatest in climates with a lot of moisture in the air or rain and snow and where there are large temperature differences between summer and winter or between daytime and nighttime.
True
True or False? Rust is an example of physical weathering
False. Rust is an example of chemical weathering. The moisture in the air reacts with iron and causes it to rust.
True or False? When plants die and decompose, they can release chemicals that break down rocks.
True and this is an example of biological and chemical weathering.