2. QUIZ What is Seismology?
What is the name of the record produced by a seismometer?
T or F Seismic waves proves the EARTH’s outer core is liquid.
What is the name of the first wave generated by an earthquake?
BONUS
Name the point on Earth’s surface that is directly above the focus of the earthquake.

3. ANSWERS
Seismology: is the scientific study of earthquakes and the propagation of vibrations through Earth
Seismograms
TRUE
P WAVE
BONUS
1. EPICENTER

4. How are EQ’s Described?
MAGNITUDE & INTENSITY

5. Magnitude
Magnitude is the measurement of the energy released during an EQ
Measured on the Richter Scale

6. Richter scale measures total amount of energy released by an earthquake

8. Measured by the Modified Mercalli Scale
Intensity
Intensity is a measure of damage caused by an EQ noted by observers during & after EQ
Measured by the Modified Mercalli Scale

10. Locating EQ’s

11. Seismologists analyze data from seismograms to Locate the Epicenter & Time of EQ occurrence

12. Locating an Epicenter
Three seismograph stations are needed to locate the epicenter of an earthquake
A circle where the radius equals the distance to the epicenter is drawn
The intersection of the circles locates the epicenter

13. Time of an EQ
The gap in arrival time between waves provides the info about the distance to the epicenter.
Time of EQ occurrence is determined by the exact time of wave arrival at the seismic station and applying it to the travel time curve

14. Travel-Time Curves

15. Locations of EQ correspond closely with tectonic plate boundaries
Seismic Belts
Locations of EQ correspond closely with tectonic plate boundaries
About 80% of all earthquakes occur in the circum-Pacific belt
About 15% occur in the Mediterranean-Asiatic belt
The remaining 5% occur in the interiors of plates and on spreading ridge centers
More than 150,000 quakes strong enough to be felt are recorded each year

18. ANY QUESTIONS?