Causes and Effects of Earthquakes

Flashcards covering key vocabulary related to the causes and effects of earthquakes.

Earthquake

A sudden movement along faults, usually at tectonic plate boundaries.

Convergent Boundary

A tectonic plate boundary where one plate subducts beneath another, causing strong earthquakes and tsunamis.

Divergent Boundary

A tectonic plate boundary where plates move apart, causing mid-ocean ridge earthquakes.

Transform Boundary

A tectonic plate boundary where plates slide past each other, creating strike-slip faults.

Ground Shaking

Vibrations caused by seismic waves traveling through the Earth's crust.

Aftershocks

Smaller tremors that follow the main earthquake.

Tsunamis

Large sea waves caused by undersea earthquakes, particularly at subduction zones.

Epicenter

The point on the Earth's surface directly above the focus where the earthquake originates.

Intensity Scale

Measures the earthquake’s impact based on human perception and building damage, using the Modified Mercalli Scale.

Magnitude Scale

Determines the earthquake's strength based on seismic wave amplitude, typically using the Richter Scale.

Philippine Fault Zone (PFZ)

A major fault system running across the Philippines.

Seismic Waves

Energy waves released by an earthquake that travel through the Earth and cause shaking.

P-Waves

Primary waves, the fastest seismic waves that can move through solids, liquids, and gases.

S-Waves

Secondary waves, slower than P-waves and move only through solids, causing more destruction.

Love Waves

Surface waves that move side to side, causing horizontal shaking and are most destructive to buildings.

Rayleigh Waves

Surface waves that move in a rolling motion, causing both vertical and horizontal ground movement.

Focus (Hypocenter)

The exact point inside the Earth where the earthquake originates due to stress release along a fault.

Shallow-focus Earthquakes

Earthquakes that occur at depths of 0–70 km and are usually more destructive.

Normal Fault

A fault caused by tensional forces where plates are pulling apart.

Reverse Fault

A fault caused by compressional forces where plates are pushing together.

Strike-Slip Fault

A fault caused by shear forces where plates slide past each other.

Seismograph

An instrument that detects and records seismic waves.

Seismogram

The visual record of an earthquake's intensity and duration.

Aftershocks

Smaller earthquakes that follow the main earthquake as the crust adjusts.