WHAT IS AN EARTHQUAKE?

By Prof. Liwayway Memije - Cruz

Earthquake – is a sudden release of energy in the Earth's crust.

SEISMOLOGY is the study of earthquakes . It studies the frequency, type and size of earthquakes over a period of time.Earthquakes are measured using observations from seismometers.

EARTHQUAKE FAULT TYPES

Normal Fault Reverse Fault Strike-slip Fault

NORMAL FAULT (Dip-slip) - Occurs when two plates pull away from each other.

REVERSE FAULT (Thrust) - Occurs where two plates push together.

STRIKE-SLIP FAULT - Occurs where two plates slip past each other

RICHTER SCALE - Used to rate the amount of energy an earthquake releases

HOW DO EARTHQUAKE WAVES TRAVEL?

• Seismic Waves - Waves of energy that travel through the Earth away from an earthquake. • Surface Waves - Seismic waves that travel along the Earth’s surface.• Body Waves - Seismic waves that travel along the Earth’s interior. > P Waves - Seismic waves that cause particles of rock to move in a back and forth direction. > S Waves - Seismic waves that cause particles of rock to move in a side to side direction.