An Introduction to Earthquakes What’s Shakin’ An Introduction to Earthquakes

Essential Questions What are seismic waves and what causes them? How do seismic waves move on and through the earth?

A Natural Disaster Video Segment Reaction to the video segment: Write two – three sentences sharing your thoughts on the video footage or your personal experience with an earthquake.

Where does the energy come from? Seismic Energy is energy released by the sudden breaking of rock within Earth. Pressure builds up within Earth from the pushing and pulling of tectonic plates. The energy released travels within Earth and along Earth’s surface in the form of seismic waves.

Rules: A ‘popping’ good time . . . You will have two minutes to play with your popper You MAY NOT launch your popper at anyone You MAY NOT purposefully hit anything At the end of the two minutes you must return your popper to the bin

A ‘popping’ good time . . . Compare the popper to seismic energy and earthquakes. How is the popper similar to an earthquake?

Why Earthquakes Happen Geologists believe earthquakes are the result of elastic rebound. Just like the plastic of the popper “bounced” back, rock “bounces” back after undergoing stress. Watch the video to better understand this… Video

Why Earthquakes Happen On your next available notebook page, illustrate elastic rebound. Draw two COLORED pictures – one of the ground under stress before an earthquake and one of the ground after an earthquake has occurred. Label your drawings. Use page ______ in your Science book to help you. Notebook Entry

Seismic Stations REMINDER: Please DO NOT touch any science or activity materials until you are told to do so. Station Expectations: You are to stay with your assigned group You will work respectfully and responsibly with the others in your group You will not move until told to do so You will clean up your station before moving on to the next station

Seismic Waves: An Introduction There are two types of seismic waves: Body Waves Surface Waves Body waves travel through a body of rock or earth. Surface waves travel along Earth’s surface.

Body Waves P-Waves Primary waves Travel the fastest Move in a back/forth direction S-Waves Secondary waves Second fastest wave Move in a side-to-side or up-and-down direction

Surface Waves Rayleigh Waves Cause the ground to move in a rolling motion. Love Waves Cause the surface to move in a side-to-side motion.

Seismic Stations REMINDER: Please DO NOT touch any science or activity materials until you are told to do so. Station Expectations: You are to stay with your assigned group You will work respectfully and responsibly with the others in your group You will not move until told to do so You will clean up your station before moving on to the next station