Why is the sea salty?
A mixture of salty substances is washed out of rocks by rivers and deposited in the sea. When rain falls on the land it gradually dissolves minerals. The dissolved salts slowly enter rivers and streams, and are carried down eventually into the sea. This process is happening all the time, and so the oceans and seas gradually become more salty.
What is the Gulf Stream?
The Gulf Stream is an ocean current that controls the climate and weather of the whole of Europe. The current starts in the Gulf of Mexico, carrying warm water across the Atlantic and travelling northeast until it reaches the European coast. Water evaporates from the surface of the Gulf Stream causing rainfall in Western Europe.
What causes waves?
A combination of wind and the shape of the sea – bed causes waves. Wind blows the surface layers of the sea, gradually forming a rolling movement of waves. As these waves near the coast, the sea – bed interrupts their rolling movement, and they mount up and break onto the beach. On beaches with a shallow slope, the waves pile up to a great height before breaking, causing surf. Out in the open sea, the waves may be very far apart, but they are closer together as they reach the shore. The highest wave ever recorded was 34 m high, during a hurricane in 1933.
