Earthquakes and Volcanoes Study

Guide

Faults Normal Fault:

Plate boundary- divergent Stress- tension

Reverse Fault: Plate boundary- convergent Stress- compaction

Strike-slip Fault: Plate boundary- transform Stress- shear

Seismic Waves P waves:

Primary waves

Come first

Back and forth motion

Travel through Solids and Liquids

S waves: Secondary waves

Sideways or side to side motion

Travel through solids only

Surface waves: Waves on Earth’s surface

Cause the most damage

Circular movement

Focus/Epicenter Focus:

Starts deep within the earth along the fault line Right where the rupture occurs

Epicenter: Point directly above the focus, on the surface of

the Earth

Hot Spots

Areas on Earth’s mantle where high temperature causes sections of Earth to rise

Heat melts the rock that is forced to the surface

Form away from plate boundaries

Examples: Hawaii, Yellowstone

Composite Volcano Eruption:

Alternate between explosive and non-explosive eruptions

Sometimes runny lava, sometime pyroclastic material type lava

Wide base/steep sides Most dangerous Alternate between explosive and non-explosive

eruptions Most dangerous

Cinder Cone Volcano

Smallest, but most explosive Lava that breaks up and shoots into the air

(pyroclastic material)Magma is viscous

Most common volcano

Shield Volcano

Very wide, but shallow/gradual slope Runny lava Non-explosive Get their name from a

warriors shield Ex: Mt. Eta