Definitions
Anatomy of an Earthquake
Earthquakes and Society
Seismic Waves
Earthquakes and Plate Tectonics
100
What is an earthquake?
A movement or trembling of the ground that is caused by a sudden release of energy when rocks along a fault move.
100
Define focus.
Focus: the location within Earth along a fault at which the first motion of an earthquake occurs.
100
What are some safety rules that may help prevent death, injury, and property damage from an earthquake? (before, during, and after)
Before an earthquake: be prepared (keep a supply of canned food, bottled water, flashlights, batteries, and a portable radio). During an earthquake: stay calm (move to a safer position). After an earthquake: be cautious (check for fire, wear shoes and avoid downed power lines).
100
What is a seismic wave?
Form of energy that is released from rocks along a fault, as they slip into new positions.
100
Earthquakes are a result of what?
result of stresses in Earth's Lithosphere.
200
What is an elastic rebound?
The sudden return of elastically deformed rock to its undeformed shape.
200
Define epicenter.
Epicenter: the point on Earth's surface directly above an earthquakes starting point, or focus.
200
How can scientists approximate forecasts of future earthquake risks?
By studying past earthquakes
200
What is the seismic wave action similar too? (hint: water..)
It is similar to what happens when you drop a stone into a pool of still water and circular waves ripple outward from the centre.
200
Where do most earthquakes occur?
Along tectonic plate boundaries.
300
What is a Tsunami?
A giant ocean wave that forms after a volcanic eruption, submarine earthquake, or landslide.
300
What is the difference between epicenter and focus.
The difference is that the epicenter is at the surface while the focus is underground.
300
what is the main cause of death and injuries during an earthquake?
Most injuries result from the collapse of buildings and other structures, or from falling objects and flying glass.
300
What are Body waves? What are the 2 categories?
Body waves: waves that travel through the body of a medium. 1) P waves 2) S waves
300
What are 3 main tectonic environment?
1) Convergent Oceanic Environments 2) Divergent Oceanic Environments 3) Continental Environments
400
What is a Seismic Gap?
An area along a fault where relatively few earthquakes have occurred recently but where strong earthquakes are known to have occurred in the past.
400
What percentage of continental earthquakes have a shallow focus?
90%
400
When does a tsunami begin to form?
it may begin to form when a sudden drop or rise in the ocean floor.
400
What are Surface waves?
A seismic wave that travels along the surface of a medium and that has a stronger effect near the surface of the medium than it has in the interior.
400
What are fault zones?
A region of numerous, closely spaced faults.
500
What is an Elastic rebound?
The sudden return of elastically deformed rock to its undeformed shape.
500
At what depths do intermediate and deep foci take place?
intermediate: 70-300 Km deep: 300-650 Km
500
On december 26, 2004, a tsunami triggered by an Earthquake hit which countries? And killed left how many people dead or missing?
Countries: Indonesia, India, Sri Lanka, and Thailand. People dead/missing: 200,000 people.
500
What are 2 types of surface waves?
1) Love waves 2) Rayleigh waves
500
where did the most widely felt series of earthquakes in the history of the united states occur?
These earthquakes occurred near New Madrid, Missouri.
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