Now let's add the hydrosphere! Millions
and trillions of gallons of water! There is so much water that it
covers all of the low spots in Earth's lithosphere. We call most
of that water the ocean. Here we see the ocean in different colors
that show the different temperatures you find on the ocean's surface.
Water near the equator is warm (light blues). Water temperatures
along the Gulf Coast of the United States reach 90 degrees in the
summertime--about like a warm bath. Water near the poles are cold
(dark purples)--cold enough to freeze into icebergs.
Water in the oceans flows
in huge currents around the edges of the continents, changing the
climate on the land. You can see the cold water flowing along the
west coast of the United States, keeping that part of the nation
cool. The warm Gulf Stream current flows up the east side of the
nation and across the Atlantic Ocean to Europe, keeping the climate
warm there. The hydrosphere also includes the water underground,
in lakes, rivers, and oceans. This water is usually fresh and is
where we get the water we drink and use in our kitchens and bathrooms.