1. Earthquakes A sudden shaking of earth as rocks break along a fault or plate boundary A sudden shaking of earth as rocks break along a fault or plate boundary Creates intense vibrations called seismic waves Creates intense vibrations called seismic waves Earthquake movie Earthquake movie Earthquake Colorado Earthquake Information Colorado Earthquake Information Colorado Earthquake Information Colorado Earthquake Information

2. Earthquakes Tensions build up in the rocks in a transform fault Tensions build up in the rocks in a transform fault Shear strength: the force needed to break rock Shear strength: the force needed to break rock

3. Earthquakes After the rock breaks it rebounds back into position releasing the energy of the break into the earth After the rock breaks it rebounds back into position releasing the energy of the break into the earth

4. Earthquakes The exact location of the break is the focus The exact location of the break is the focus The epicenter is the location on the earth’s surface just above the focus The epicenter is the location on the earth’s surface just above the focus

5. Magnitude and Intensity Magnitude is the size of the s and p waves Magnitude is the size of the s and p waves Intensity is how much damage was caused Intensity is how much damage was caused Sometime a magnitude 6 earthquake can be more intense than a 7 Sometime a magnitude 6 earthquake can be more intense than a 7

6. Magnitude and Intensity Magnitude is measured with the Richter Scale Magnitude is measured with the Richter Scale 0-10 numbers go up by magnitudes of 10X 0-10 numbers go up by magnitudes of 10X 5 is 10X greater than 4 5 is 10X greater than 4 * How much greater is a magnitude 8 than a magnitude 6 earthquake?

7. Magnitude and Intensity Intensity is measured with the Mercalli Scale Intensity is measured with the Mercalli Scale Based on the amount of damage caused Based on the amount of damage caused Use the scale on page G141-G143 to rank the following earthquakes Use the scale on page G141-G143 to rank the following earthquakes

8. San Francisco 1989

9. Anchorage Alaska 1964

10. Szechuan China 2005

11. Haiti 2010