Download Hydrosphere U2-3

After your test . . .
Using the Parts of a River Vocabulary draw a
diagram of a River System. Diagram must
include all of the Vocabulary provided and
must be labeled.
Pages 15 & 49
can help with
your diagram.
The Four Spheres of the Earth
• Atmosphere: the air
• Lithosphere: the earth’s crust
• Hydrosphere: Oceans, lakes, rivers and
other bodies of water
• Biosphere: the part of the earth that
supports life
The Hydrosphere
• About 70% of the earth’s surface!
• Factor for settlement.
The Water Cycle
• Run and get a glass of water and put it
on the table next to you. Take a good
long look at the water. Now -- can you
guess how old it is?
• The water in your glass may have fallen
from the sky as rain just last week, but
the water itself has been around pretty
much as long as the earth has!
The Water Cycle
Evaporation
• The water cycle has no starting point. But,
we'll begin in the oceans, since that is
where most of Earth's water exists. The
sun, which drives the water cycle, heats
water in the oceans. Some of it evaporates
as vapor into the air.
Evapotranspiration
• Water transpired from plants and
evaporated from the soil.
Do plants sweat?
Condensation
• Water vapor in the air gets cold and changes back into
liquid, forming clouds. This is called condensation.
• Air currents move clouds around the globe
• You can see the same sort of thing at home... pour a
glass of cold water on a hot day and watch what
happens. Water forms on the outside of the
glass. That water didn't somehow leak through the
glass! It actually came from the air. Water vapor in
the warm air, turns back into liquid when it touches the
cold glass.
Precipitation
• Precipitation occurs when so much water
has condensed that the air cannot hold it
anymore. The clouds get heavy and water
falls back to the earth in the form of rain,
hail, sleet or snow.
Collection
• When water falls back to earth as precipitation, it may fall
back in the oceans, lakes or rivers or it may end up on
land. When it ends up on land, it will either soak into the
earth and become part of the “ground water” (infiltration).
Some water infiltrates deep into the ground and
replenishes aquifers (saturated subsurface rock), which
store huge amounts of freshwater for long periods of time.
Some infiltration stays close to the land surface and can
seep back into surface-water bodies and some ground
water finds openings in the land surface and emerges as
freshwater springs. Over time, though, all of this water
keeps moving, some to reenter the ocean, where the
water cycle "ends" ... oops - I mean, where it "begins."
Bodies of Salt Water
• Oceans About 97 percent of the hydrosphere is a
huge body of salt water divided into five oceans:
the Atlantic, the Pacific, the Indian, Southern
and the Arctic Oceans.
• Seas, Gulfs, and Bays Large bodies of salt water
partially enclosed by land comprise seas, gulfs,
and bays
How can we use this water?
Desalination: converts ocean water into drinking water
Why aren’t we all doing this?
Water Shortages
• How can human actions affect our water
supply?
• Does the water disappear during a
drought?
• Water from Thin Air?