Vocabulary
What is the start of the earthquake?
The Focus
What does a seismograph measure?
Seismic waves from an earthquake.
Define Refraction
When a wave changes direction
What is the three names of the Primary Wave?
Primary Wave
P Wave
Compression Wave
What is it called when you find three areas that felt an earthquake that overlap?
Triangulation
What is located directly above the focus, where the waves break the surface?
The Epicenter
What does a Richter scale measure?
The Magnitude of an earthquake.
What causes the refraction of a wave?
The material that the wave is moving through because it speeds up or slows down.
What is the three names of the Secondary Wave?
Secondary
S Wave
Shear Wave
If Dallas had 2 minutes and 30 seconds between waves and Houston had 3 minutes between waves, which city is further from the epicenter and Why?
Houston, because the time is longer when the waves were felt.
What is the measure of energy released by an earthquake?
Magnitude
What scale measures how strong the earthquake was based on the amount of destruction it causes?
What is the Mercalli Scale
What is it called when waves do not pass through a certain area?
Shadow Zone
Give the 3 names of the Surface Wave.
Surface Wave
L Wave
Long Wave
How do you find the distance (Km) from the epicenter?
After counting the minutes and seconds on graph and drawing boxes, you count number of squares and multiply it by 200.
What causes an earthquake to happen?
When plates slide past each other and rock breaks. (a fault occurs)
Which of the three scales is the least scientific?
The Mercalli, because it is based on human witnesses.
Which wave is most commonly refracted?
The Secondary Wave
When a seismograph records the waves, what is the flat line between the wave recordings?
The amount of time that passes between the P wave and the S wave.
What is the relationship between the number of minutes between the P and S wave in relation to the epicenter?
The more time between the P and S wave, the further the distance from the epicenter.
What is the scale called that describes a witness account of what they see happening in an earthquake?
Mercalli Scale of Intensity
Which scale has the largest number and what is it?
The Mercalli, 12
How do scientists know that certain waves do not pass through the core?
They study the shadow zones and watch which layers refract.
Name the three ways that waves move from the focus of an earthquake.
P-wave moves parallel
S wave moves perpendicular
L wave moves like a roller coaster
When drawing the circles on your map, how do you know where the Epicenter is located?
Where the three circles overlap and have in common.