6.4) Earthquakes Flashcards
What are some hazardous geological phenomena that are more common near plate boundaries?
- Earthquakes
- Tsunamis
- Volcanic eruptions
- Lahars
- Geysers
- Sulfur dioxide gas
What causes earthquakes?
Earthquakes are caused by a build-up of pressure and the release in Earth’s crust
Where do earthquakes mostly occur?
Earthquakes mostly happen along tectonic plate boundaries - divergent
What does energy pass through Earth as?
Energy passes through Earth as seismic waves that move/shake the crust
What is the epicenter?
The epicenter is the point on earth’s surface directly above the focus of an earthquake
What is the focus?
The area in the curst where energy is released during an earthquake
(where the earthquake begins)
What is the fault line?
A fault line is a long crack in the surface of the earth
What are the two main types of seismic waves?
Body waves and surface waves
Describe body waves?
Body waves travel through the earth
Primary - longitudinal - faster
Secondary - transverse
Describe surface waves?
Surface waves travel through the Earth’s surface
Define earthquake
An earthquake is the shaking of the surface of the Earth resulting caused by a sudden release of energy in the Earth’s lithosphere that creates seismic waves
What are the four parts of an earthquake?
- Focus
- Fault
- Epicenter
- Seismic waves
What is the function of seismometers
The seismometer main function is to detect any movement of the ground through the seismic waves
What is the function of the mercalli scale
a scale to measure the intensity of earthquakes.
ranges from 1 to 12
