The hydrosphere is all the water on the
planet. It is made up of oceans, rivers, seas,
lakes, glaciers, groundwater and water vapour
Water cycle 1. Evaporation: water evaporates.
2. Condensation: clouds formation.
3. Precipitation. Rain from clouds.
Saltwater (97% of Earth), in oceans and seas.
- Salinity (amount of salt). Higher in hot and closed
- Temperature: higher in the surface, colder in the
- Denser than fresh water.
Fresh water (3%), on continents and islands.
- Most of it is at polar regions and glaciers.
- Some groundwater.
- Only al ittle in water vapour and lakes or rivers.
Oceans and seas.
Seas are oceanic waters close to
continents. They are not as deep as
oceans. Some are part of the ocean, other
are connected through narrow straits.
Some are interior.
Oceans are vast masses of saltwater
separating the continents. They cover a
large proportion of the Earth’s surface.
Some seas are extremely
salty, because of evaporation
or human explotation.
Life is difficult to find
The Aral Sea is an
Example of a natural disaster
Provoked by human hand.
Overexplotation of rivers led
To the drying out of the sea.
Main ocean currents.
Ocean currents are large masses of water moving across the ocean.
They are warm and cold currents, and they move because of their differences
In density, salinity and temperature.
Currents and climate.
Newfoundland (Terranova, Canada) Brittany (Bretaña, France)
Temperature of ocean currents has a strong influence on climate. Brittany and
Terranova are at the very same latitude; however, temperature differences are
Higher than 10 degrees during winter.
Rivers: flowing currents of water
Stages of a river:
-Upper course: flows rapidly, with river valleys.
-Middle course: meandres.
-Lower course: river flows slowly, river mouth.
Flow will be determined by rainfall and soil.
The rapid flow erodes easily the bedrock
And creates sharp valleys(Los Pilones, Jerte)
UPPER COURSE OF A RIVER
Sand sediments on the lower
Course of river Tietar, tributary
of river Tajo (Casatejada,