Earthquakes and Tsunamis
By: Addie Jo Welch
Earthquakes
Earthquakes are vibrations caused by movement along fractures in the crust. Earthquakes usually occur when rocks fracture or break deep in Earth.
Types of Waves
Primary Waves
P- waves pull and squeeze the rocks in the same direction.
Secondary Waves
S-waves cause rocks to move right angles to the direction of waves.
Surface Waves
Surface waves travel along the surface. They move in two directions as they pass through rock.
Tsunamis
Tsunamis are gravity waves created by rapid displacement of a water column. Tsunamis can come from earthquakes, landslides, or volcanic eruptions. When the wavelengths hit shallow water, they build up amplitude and become up to hundreds of meters high.