Understanding Earthquakes

What causes earthquakes to occur along faults?

• Movement of water underground

• Sudden release of energy due to rock movement

• Changes in weather patterns

• Volcanic eruptions only

What is an earthquake?

• A sudden explosion underground

• A shaking of the ground caused by the sudden release of energy in the Earth's crust

• A movement of wind in the atmosphere

• A shift in ocean currents

What does the Elastic Rebound Theory explain?

• How volcanic eruptions cause earthquakes

• How rocks bend and store energy before breaking, causing an earthquake

• How humans can predict earthquakes

• How water flow affects the movement of tectonic plates

According to the Elastic Rebound Theory, what happens after the rock breaks along a fault?

• The rock stays in its deformed shape

• The stored energy is released, causing an earthquake

• The rock softens and melts

• The ground becomes permanently flat

What do we call the point underground where an earthquake starts?

• Epicenter

• Focus (Hypocenter)

• Fault line

• Seismic zone

What is the epicenter of an earthquake?

• The deepest point of the fault

• The location on the Earth's surface directly above the focus

• The point where seismic waves stop

• The boundary between two tectonic plates

Which seismic wave travels the fastest and is the first to be detected?

• Primary (P) Waves

• Secondary (S) Waves

• Surface Waves

• Tsunami Waves

What is the main difference between P-waves and S-waves?

• P-waves travel through solids and liquids, while S-waves travel only through solids

• P-waves move slower than S-waves

• P-waves move up and down, while S-waves move side to side

• S-waves are the most dangerous type of seismic wave

Why are surface waves more destructive than body waves (P and S waves)?

• They travel faster and reach deeper underground

• They move along the Earth’s surface, causing more damage to buildings and structures

• They are the first waves to be detected

• They occur only during tsunamis

Why does the Philippines experience frequent earthquakes?

• It is located in the Pacific Ring of Fire, where multiple tectonic plates interact

• The country has a flat and stable land structure

• The Philippines is covered by thick forests that attract seismic activity

• The country experiences strong winds that cause shaking