before we start the story are will tall you what  earthquake is and what dose it do? 

Earthquakes are plates suddenly slip and Energy is released and the ground shakes back and forth.

it is like when you push two books togther really hard, and than they suddenly slip- that quick movement is like an earthquake.

scientists know an earthquake  is happening by using  special machines  that the ground shake.

The name of the thing the seismometers.

earthquake happen because the earth is made of big pieces called plates that are always moving.

sometimes he plates get stuck  when they push against. 

when the pressure  gets too bug the plates suddenly slip. so when it slip it can cause energy and release the ground shakes.

tools that  scientists use.

they are 4 tools they are called Seismometer,  seismograph, GPS,

Seismometer this tools feels the shaking of the ground even vary tiny shakes.

Seismograph records the shaking as wavy lines so scientists can study it.

Satellites  these take pictures of earth from space to see cracks or changes after an earthquake.

GPS shows how the ground slowly moves over time.