Locating An Earthquake Epicenter

Question 1

-the vibrations produced by earthquakes; these are detected by seismographs

-by studying these waves the epicenter of an earthquake can be located

Answer 1

Seismic Waves

Question 2

the study of earthquakes, their effects, and seismic waves.

Answer 2

Seismology

Question 3

the graph output of a seismograph

which is used to determine the epicenter of an earthquake

P-waves always appear before S-waves, as they travel faster and can travel through three states of matter as opposed to one.

Answer 3

Seismogram

Question 4

Seismic Waves

also called primary or compressional waves. The following are the four important things to remember about P waves:

1. They travel the fastest.
2. They travel in the same direction as the particles they vibrate.
3. They travel through solids liquids, and gases.
4. They travel faster through denser materials (density increases with depth on the earth).

Answer 4

P waves

Question 5

Seismic Waves

also called secondary or transverse waves. The following are the four important things to remember about S waves:

1. They travel slower than P waves.
2. They travel at right angles to the vibration of the particles.
3. S waves cannot pass through liquids or gases.
4. They travel faster through denser materials.

Answer 5

S waves

Question 6

To determine the distance of an earthquake epicenter:

Answer 6

1. Determine the arrival times of the P-wave and the S-wave.
2. Calculate the difference between the arrival time of the P-wave and the S-wave.
3. Referring to the Earthquake Time Travel Graph below, determine the location on the graph where the two lines have a difference in their y values equal to the time difference you previously calculated. The x value at this location is the distance to the epicenter of the earthquake.