Earthquakes Flashcards
20 questions;
What is an earthquake?
An earthquake is the sudden shaking/movement of the ground. They can be large or small and can happen basically anywhere.
Why do they occur?
What happens after they occur?
- They occur when a rock breaks beneath the surface of the earth. After it breaks, the pieces of the rock snap together and move along a fault.
What is a fault?
A crack in a body of rock.
What are seismic waves and what types of waves do they have?
Seismic waves:
Waves of energy that travel through earths surface, they cause the earth to crumble and shake during earthquakes.
Types of seismic waves:
- P- waves: (fastest wave)
- S- waves: secondary waves (wave occurs right after earthquake)
What are the 3 type of faults?
- Normal faults
- Reverse faults
- Strike- Slip Faults
What can an earthquake effect?
Tunnels, buildings, roads, and even gaslines.
What can occur if an earthquake happens on the ocean floor?
A tsunami.
How often do small magnitude earthquakes happen?
Every 10 seconds!
Where do most earthquakes occur?
They occur mostly near the boundaries of tectonic plates!
What are the different boundaries// what do they have?
- Divergent boundaries : pull apart; shallow earthquakes ; common along normal faults
- Convergent: plates collide; common along reverse faults
- Transform: shallow; happen along strike-slip-faults
True or false:
Older buildings tend to withstand the earthquakes better than newer
That is… False.
True or False:
There are more than one scale to measure an earthquakes magnitude.
True!
Fill blank:
The strength of an earthquake is caused by _____.
rocks
Fill blank:
________ are used to measure seismic waves and when the waves reach it, it produces a ________.
Seismometers are used to measure seismic waves and when the waves reach it, it produces a seismogram.
What are 2 other kinds of seismic waves?
Surface waves: Surface waves travel along the surface which causes more damage
Body waves: body waves travel through earths interior and move faster
What is magnitude?
The amount of energy released by an earthquake.
How is earthquake magnitude found?
They find the height of the waves on it and the amount of ground motion to find the magnitude.
How much more ground motion is measuredafter increasing it by one unit?
The ground motion gets 10x greater.
What is liquefaction?
Liquefaction is can cause the ground to settle and structures tilt.
How is magnitude measured?
The Richter scale
- Charles richter
