About forty years ago,scientists exploring the seafloor found that it is full of tall mountains and deep trenches. A single seafloor mountain chain circles Earth and contains some of Earth’s tallest mountains. Along this mountain chain is a deep crack in the top layers of Earth. Here the seafloor is pulling apart and the two parts are moving in opposite directions, carrying along the continents and oceans that rest on top of them. These pieces of Earth’s top layer are called tectonic plates. They are moving very slowly, but constantly. (Most plates are moving about as fast as your fingernails are growing -- not very fast!) Currently Earth’s surface layers are divided into nine very large plates and several smaller ones.
Where one tactonic plate meets another it sometimes dislocate the other plate downward or else , and thus suddenly plates move,this energy travel as wave along medium of land and water.Thus this cause Earth-quake or Sunami Waves.These disasters should be forecasted well-before so lives and property losses can be avoided.Many systems are available nowadays which can predict or can inform faster then this waves to the location about hazzard with all necessary informations , some of them are connected with settelites,also.Image shown below gives idea about poisition of tactonic plates.But remember this plates are moving constantly with some velocity.Thus area shown in green rectangles tells about most probable are for quakes , because plates are meeting in this zone increases probability of quake in this zone.
