What are earthquakes?
Vibrations in the ground resulting from movement along breaks in Earth’s lithosphere
Earthquakes occur due to tectonic activity.
What is the difference between shallow and deep earthquakes?
- Shallow: Common where plates separate along a divergent plate boundary
- Deep: Occur when a break in Earth’s lithosphere happens at greater depths
Shallow earthquakes are typically less than 70 km deep, while deep earthquakes can occur at depths greater than 300 km.
Define strike-slip fault.
Two blocks of rock slide horizontally past each other in opposite directions
This type of fault is often associated with transform plate boundaries.
What is a normal fault?
Forces that pull two blocks of rock apart
Normal faults typically occur at divergent boundaries.
Define reverse fault.
Forces push two blocks of rock together
Reverse faults are commonly found at convergent plate boundaries.
What are seismic waves?
Waves that originate where rocks first move along the fault
Seismic waves are responsible for the shaking felt during an earthquake.
What is the focus of an earthquake?
A location inside the earth where rocks move along the fault
The focus is the point where the earthquake originates.
What is the epicenter of an earthquake?
The location on the Earth’s surface directly above the earthquake’s focus
The epicenter is often the area that experiences the most intense shaking.
What do Primary Waves cause particles in the ground to do?
Move in a push-pull motion
Primary Waves are the fastest seismic waves.
What do Secondary Waves cause particles to do?
Move up & down at right angles
Secondary Waves are slower than Primary Waves.
What motion do Surface Waves cause particles in the ground to have?
Move up & down in a rolling motion
Surface Waves typically cause the most damage during an earthquake.
Who are Seismologists?
Scientists that study earthquakes
They analyze seismic waves to understand earthquake behavior.
What is Triangulation used for in seismology?
To locate the Earth’s epicenter
This method involves using data from multiple seismic stations.
What does the Modified Mercalli Scale measure?
The earthquake’s intensity
It assesses the effects of an earthquake on people and structures.
What does the Richter Scale measure?
The earthquake’s magnitude
It quantifies the energy released at the source of the earthquake.
What is a Volcano?
A vent in Earth’s crust from which molten rock flows out of
Volcanoes can form through tectonic activity.
What is Magma?
Molten rock below Earth’s surface
When magma erupts, it is called lava.
Where do volcanoes form and why?
At Earth’s tectonic plates
Tectonic activity causes the formation of volcanoes.
What are Hot Spots in geology?
Areas where molten rock rises to the surface
Hot Spots can create volcanoes away from tectonic plate boundaries.
