Rapid and Gradual

Changes of the

Earth’s Surface

Standard Three – Objective Four

Rapid and Gradual ChangesVolcano-a mountain that forms when molten rock, called magma, is forced to the Earth’s surface.

Nonexplosive EruptionsLava-is magma that flows onto the Earth’s surface.

Explosive EruptionsClouds of hot debris and gases shoot out from the volcano often at supersonic speeds.

Don’t Try This at HOME!!

Earthquakes It is self defined!!!! Shaking of the EARTH!!!

Seismology-the study of earthquakes.

Deformation-the change in the shape of rock in response to stress.

Plastic deformation-rocks bend like clay, they do not cause earthquakes.

Elastic deformation-rocks will break, they will cause earthquakes.

How do Earthquakes Travel?

Seismic waves-waves of energy that travel through the Earth.

P waves-(Primary) travel through solids, liquids, and gases, are the fastest seismic waves.

S waves-(Secondary) shear waves are the second-fastest waves. They cannot travel through parts of the Earth that are completely liquid.

Surface Waves-move the ground up and down in circles as the waves travel along the surface.