Warm up 9/27/2016 ( 10 min) Label the diagram A-G Volcano B. trench C. Oceanic crust D. asthenosphere E & F. Continental crust G. Subduction

Objective and EQ 2.1.1 Describe the anatomy of an earthquake. EQ- How do seismic waves move?

SEISMIC WAVES Seismic waves are the vibrations (waves) of energy released by a quake! Two Types Body Waves Surface Waves Seismology is the study of earthquakes and seismic waves. 4

1st type BODY WAVES (P and S) P WAVES (P= Primary) - Fastest (6 km/s) - Causes ground to squeeze and stretch like a spring! - Can travel though solids, liquids, & gas Cause ground to compress and stretch in direction in which wave is travelling. 5

BODY WAVES (P and S) S WAVES (S= Secondary) - Slower (3.5 km/s) - Can travel though solids (not liquids) Also known as shear waves. Cause ground to compress and stretch at right angles to direction of wave’s motion. 6

2nd Type Surface Waves Surface Waves travel along the earth’s surface. Larger than body waves and most destructive Love Wave: Lateral movement of the surface Rayleigh Wave: Rolling movement of the surface (similar to an ocean wave)

Seismic Wave Review P Waves S Waves Surface Waves

Recording Seismic Waves Seismograph: An instrument that measures the horizontal or vertical motion of Earth’s surface Seismograms: Shows all three types of seismic waves—surface waves, P waves, and S waves

Major Hazards of Earthquakes Building Collapse Landslides/Mudslides Fire Tsunamis (Not Tidal Waves!)

Pair Work What are the different kinds of seismic waves? Types of seismic waves Chart If you haven’t completed the fault worksheet, please work on that as well.

WARM UP 9/28/2016 If there was news that an earthquake or (any natural disaster) was headed for Charlotte, NC, what are some things you and your family would need in your emergency kit?

Agenda Warm up 1906 San Francisco Earthquake Notes on Measuring Earthquakes Lab on Finding Epicenters

1906 San Francisco Earthquake https://youtu.be/AhPpp7As8k8

Objective EEn.2.1.2 Predict the locations of volcanoes, earthquakes, and faults based on information contained in a variety of maps.

Essential Question How can I locate the epicenter of an earthquake?

Epicenter located using three seismograph stations The point where the three circles meet is the location of the earthquake epicenter.

Locating an Earthquake

When an earthquake happens, scientists want to know where it happens. Scientists need to find the epicenter. Scientists need to find the source. Epicenter = Distance in the Difference in TIME between the P wave and the S wave!! -

HOW SCIENTISTS USE THIS SCENARIO 1: Watch the watch! What’s the time difference? Answer 1 _____________________ SCENARIO 2: A P Wave arrives at the seismograph station 3 minutes after an earthquake. An S Wave arrives 8 minutes after an earthquake. What is the difference in arrival time? Answer 2 ______________________ SCENARIO 3: At 10:32 a P Wave arrives. At 10:45 and S Wave arrives. What is the difference in arrival time? Answer 3 _______________________

SCENARIO #1 Determine the difference in the travel-times between the first P wave and the first S wave, if the seismic station is 1500 miles from the epicenter. Read the problem and box in key words. Identify the information on the axis. Plot your points to find data. ________________________ Subtract your data. __________ - __________ = _________

SCENARIO #2 Determine the difference in the travel-times between the first P wave and the first S wave, if the seismic station is 500 miles from the epicenter. Read the problem and box in key words. Identify the information on the axis. Plot your points to find data. ________________________ Subtract your data. __________ - __________ = _________

SCENARIO #3 Determine the difference in the travel-times between the first P wave and the first S wave, if the seismic station is 2,000 miles from the epicenter. Read the problem and box in key words. Identify the information on the axis. Plot your points to find data. ________________________ Subtract your data. __________ - __________ = _________

Measuring the size of earthquakes Two measurements describe the size of an earthquake Intensity – a measure of earthquake shaking at a given location based on amount of damage Magnitude – estimates the amount of energy released by the earthquake

Earthquake Magnitudes

Intensity scale Modified Mercalli Intensity Scale was developed using California buildings as its standard

Based on amplitude of largest seismic wave recorded Magnitude scales Richter scale Based on amplitude of largest seismic wave recorded

Richter Scale Magnitude Level Earthquake Effects Estimated Number Each Year less than 1.0 to 2.9 generally not felt by people, though recorded on local instruments. More than 100,000 3.0-3.9 felt by many people; no damage 12,000-100,000 4.0-4.9 felt by all; minor breakage of objects 2,000-12,000 5.0-5.9 Some damage to weak structures 200-2,000 6.0-6.9 moderate damage in populated areas. 20-200 7.0-7.9 8.0 or higher serious damage over large areas; loss of life severe destruction and loss of life over large areas 3-20 Fewer than 3

7.8 magnitude (China, 2008)

7.0 Haiti 2010

Japan, 2011, one of the most massive earthquakes in history, measuring 9.0 on the Richter scale

Tsunamis Destructive “tidal waves” A tsunami is triggered by an earthquake. A tsunami also can occur when the vibration of a quake sets an underwater landslide into motion. Tsunami is the Japanese word for “seismic sea wave.”

Formation of a tsunami Tsunamis are actually huge, extending from the fault on the sea floor up to the surface, but they don’t stick up more than a meter or so in the deep ocean. However, when they reach shallow water they must rear up and slow down. Discussion: Kinetic vs. potential energy