Vocabulary Terms
Earthquake definition
Sudden strong movements of the crust caused by the breaking and shifting of underground rock (plate tectonics).
The most active region for earthquakes in the world
The Ring of Fire.
4 types of seismic waves
P wave, S wave, Rayleigh wave, and Love wave
Used to measure seismic waves and produces a seismograph.
Seismometer
Ways to prepare for an earthquake
Create an emergency kit, put together a plan with family and friends, secure heavy items in your home, etc.
Fault definition
A fracture / zone of weakness in the ground between blocks of Earth's crust, and is where earthquakes occur along (fault line).
Three types of plate boundaries
Convergent, Divergent, and Transform.
Why it is important to study seismic waves
By analyzing how waves reflect and refract, Earth's internal structure can be revealed so that scientists can identify and learn more about it.
Scale from 1-9 measuring the magnitude of an earthquake (higher the number, stronger the earthquake).
The Richter Scale
Ways to stay safe during an earthquake inside a building.
Stay inside. Avoid doorways and drop under a heavy desk or table.
Focus definition
This is the point beneath the Earth's crust where the earthquake starts.
What are plate tectonics?
The theory that the Earth's lithosphere is divided into several large, rigid plates that slowly move around in the earth's upper mantle.
Difference between surface waves and body waves
Body waves travel through the inner layers of the Earth. Surface waves only move through the crust. Surface waves cause the most destruction during an earthquake.
Importance of recording earthquakes
It is important for assessing potential hazards, improving building codes to save lives, and understanding tectonic processes.
To reduce injury / prevent death and lessen damage, as earthquakes strike instantly without warning.
Epicenter definition
This is the place on the Earth's surface that is directly above the focus.
What plate boundary causes the most destructive earthquakes?
Convergent plate boundaries.
This is the fastest type of wave and is a body wave. It moves the ground in a back and forth (push-pull) motion. It can move through solids, liquids, and gases.
P wave
Not very scientific tool, but uses the observations of the people who experienced the earthquake to estimate its intensity.
The Mercalli Scale
Ways to stay safe in an earthquake outside
Stay there. Move to an open area away from buildings, trees, streetlights, and power lines. Drop and cover until shaking stops to protect from flying debris.
Seismic wave definition
They are vibrations of energy that can be released by earthquakes that travel through the Earth's interior and along its surface.
Cause of earthquakes
Tectonic plates underneath Earth's surface shift and cause stress. When the stress becomes too much, it releases in sudden movements (earthquakes).
This is the slowest of all seismic waves, and is a surface wave. It moves the ground in a circular pattern, similar to waves rolling across the ocean.
Rayleigh wave
The modern (and pretty standard) scale for measuring the total energy released by earthquakes, especially large ones.
Moment Magnitude Scale (MMS)
What to do in a car during an earthquake
Pull over, stop, and stay inside. Set your parking brake.