When the volume of water in a river increases so much that the river overflows its channel.
flood
100
The type of water found in the Great Lakes.
fresh water
100
An area of land that is covered with a shallow layer of water during some or all of the year.
wetland
100
A huge mass of ice and snow that moves slowly over land.
glacier
100
The addition of any substance that has a negative effect on water or the living things that depend on water.
water pollution
200
The area of rich sediment deposits that build up near a river's mouth.
delta
200
Water that flows over the ground surface into ponds and lakes rather than soaking into the ground.
runoff
200
Name any freshwater wetlands.
marsh, swamp or bog
200
A hazard to ships because 90% of its mass lies unseen below the surface of the ocean.
iceberg
200
Any precipitation that falls with a pH below 5.6.
acid rain or acid precipitation
300
The many small streams that come together at the source of a river.
headwaters
300
A natural or artificial lake that stores water for human use.
reservoir
300
Name one saltwater wetland.
salt marsh or mangrove forest
300
Explain how a glacier forms.
Layers of snow pile on top of one another over time. The weight of these layers press the snow so tightly together that it forms a solid block of ice.
300
A specific source of pollution that can be identified such as a pipe gushing white sudsy water into a river.
point source
400
A looping curve formed in a river that can carve a new channel.
meander
400
In the fall lake waters cool and become denser and sink causing minerals, plant matter and other nutrients to rise from the lake bottom to the surface refreshing the supply of nutrients throughout the lake.
lake turnover
400
One of the largest wetlands in the United States is located in southern Florida and is home to many endangered species.
the Everglades
400
Ice sheets that are spread over a large area of land such as in Antarctica.
continental glaciers
400
A widely spread source of pollution that can't be tied to a specific point of origin such as runoff from a farm field.
non-point source pollution
500
The crescent-shaped body of water created by a meander.
oxbow lake
500
The process by which nutrients in a lake build up over time causing an increase in the growth of algae. As plants die they pile up on the lake's bottom causing the lake to become shallower and eventually creating a grassy meadow.
eutrophication
500
Besides providing habitats for many living things, wetlands are also important to humans for this reason.
act as sponges to help control flooding by absorbing extra runoff from heavy rain
500
Glaciers that form in the mountains, such as the Alps, that look like rivers of ice sliding down the mountain.
valley glaciers
500
Explain how fertilizers can cause water pollution.
Runoff from farms and lawns carry fertilizers into ponds and lakes increasing the growth of algae causing eutrophication to occur.