Faults

1. Faults “Little” Cracks in the Earth’s Crust

2. Faults are cracks in the Earth’s Crust where the rock on either side is moving in different directions. • Faults can be large or small but they DO NOT have to be at the edges of the plates. • Plate Boundaries occur at the edges of the very large tectonic plates. • Most of the earthquakes occur at Plate Boundaries. Faults vs. Plate Boundaries

3. Scientists are still discovering new faults. Many of these new discoveries are made my UW Geology professors and students. Recently discovered Faults

4. Discovered in 1965 The Seattle fault zone http://www.washington.edu/alumni/columns/top10/fault.html This is a good but scary article on the Seattle Fault.

5. If you live near a fault are earthquakes your friend? Let’s Think It through:

6. As the crust moves rock along the fault line catches due to “friction” (stick). • As the crust continues to move pressure builds up in the areas of stick. • When the fault finally ruptures (slip) energy is released in the form of an earthquake. • The greater the stick force, the greater the slip will be and the more energy released via the earthquake. • More smaller earthquakes mean that the pressure never really builds up much (small stick = small slip). When the rock around the faults stops moving scientists worry lots of pressure is building up and may result in a very large quake. The big ideas for the fault lab (Inquiry 15.3)

7. Goggles • 2 wooden blocks with Velcro • 1 string • 1 spring scale • 1 roll of • masking tape • 1 bolt • 2 washers • 1 wing nut Materials List