What portion of precipitation falls directly into the oceans?
More than 75% (about 78%)
Approximately how long does it take for most glaciers to form?
over 100 years
What are areas of permeable sediment or rock that hold significant amounts of water?
aquifers
What two main forces drive the water cycle?
The Sun & gravity
Water that lies below the ground is _______________________
groundwater
As water vapor rises in the atmosphere, what happens to it?
it cools and condenses or crystallizes
These are areas of permeable sediment or rock that hold and transmit significant amounts of water underground.
aquifers
How does groundwater become surface water?
It seeps back out of the ground and into a lake, streams or wetlands
This term describes moisture that falls from clouds to Earth's surface (rain, snow, sleet, hail)
precipitation
What is water that collects on the surface of the ground?
surface water
What is water in its gaseous state?
water vapor
The process by which water from Earth’s surface becomes water vapor and enters the atmosphere is called ____________________
evaporation
A place in the water cycle where water is stored for relatively long periods of time
reservoirs
What is true of groundwater in dry places like the desert?
it is found hundreds of meters below the surface
How are lower layers of snow turned into glacial ice?
pressure from the top layers press it down
This is the main source of energy that causes water at Earth's surface to evaporate.
The Sun
What causes glaciers to flow downhill?
Gravity
When precipitation falls on land, it can do what?
evaporate back into the atmosphere
flow into streams or rivers which will eventually go back to the ocean
How does the total amount of water on Earth change?
it doesn't; it is stable
Water moves from Earth's surface to the atmosphere and back again in the ___________________
water cycle
How does global warming affect the cycling of water?
increased rates of evaporation and more intense precipitation
or drier climates due to very warm air
What are some examples of reservoirs?
oceans, lakes, streams, glaciers, ice caps, and groundwater