1. Rapid and
Gradual
Changes of the
Earth’ s Surface
 Standard Three – Objective Four

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

3. Nonexplosive Eruptions
 Lava-is
magma that flows onto the Earth’s
surface.

5. Explosive Eruptions
 Cloudsof hot debris and gases shoot out
from the volcano often at supersonic speeds.

8. Don’t Try This at HOME!!

9. 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.

10.  Plastic deformation-rocks bend like clay, they do
not cause earthquakes.
 Elastic deformation-rocks will break, they will
cause earthquakes.

11. 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.

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

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