Daily Review #4 Describe the 4 different pieces of evidence to support continental drift How does convection cause a plate to move? Discuss your answer to the writing prompt about what you think will happen to the continents in 100 million years.

Plate Tectonics Movement ◦ cm/yr ◦ Measured by GPS Interact at boundaries – 3 types ◦ Collide ◦ Separate ◦ Slide past Earthquakes can occur at all

Convergent Boundary Plates collide Continental- continental ◦ Create mountains Continental-oceanic ◦ Oceanic sinks ◦ Subduction zone and trench ◦ Remelted, recycled Oceanic-oceanic ◦ One subducts

Transform Boundary Plates slide past each Not usually smooth Larger, more frequent earthquakes

Earthquakes What are they? What is it like? Seismologist Where? ◦ Plate boundary ◦ Rarely in middle of continent ◦ Occur at or create faults ◦ Varying depths ◦ Focus  Epicenter

How are earthquakes measured? Richter scale ◦ Strength (magnitude) ◦ Measuring ground motion ◦ Used by the media Moment magnitude ◦ More precise ◦ Measures the energy released ◦ Measured at the epicenter ◦ Used by scientists

Largest Recorded Earthquakes Recent earthquakes

Imaging of Earthquake Waves Seismograph ◦ Shows local movement ◦ 3 main waves 1.P wave 2.S wave 3.Surface waves

Finding the Epicenter Distance vs. time graph is constant ◦ Closest has smallest time difference Measure time difference on local seismograph ◦ Compare to graph ◦ Find distance Repeat for multiple locations

Finding Epicenter cont. Use distances found Draw a circle from each site Overlap = epicenter

Daily Review #5 How are convergent and transform boundaries similar? Different? Give a current example of a convergent boundary and what is being formed there What is an epicenter and how is it found? What kind of damage can an earthquake cause and how do you think we could prevent that damage?

Elastic Rebound Hypothesis Energy builds Energy released ◦ Travel as waves Rocks return to original shape, but different locations

Earthquake Waves P waves ◦ First detected ◦ Back-and-forth S waves ◦ Side-to-side ◦ Slower, arrive later

Surface ◦ Rolling ◦ Side-to-side ◦ Slowest ◦ More destructive Aftershocks Foreshocks

Earthquake Hazard Map

Earthquake Prediction Not exact Seismic gaps ◦ Area of fewer earthquakes ◦ Likely location of future earthquake ◦ Used to predict 1989 San Francisco Past frequency

Destruction from Earthquakes Liquefaction ◦ Mixing soil with underground water ◦ Sinkholes Landslides Fire ◦ Broken gas and electrical lines ◦ Lack water to fight Building and highway damage

Tsunami Cause ◦ Underwater earthquake ◦ Ocean floor movement Massive waves Closer to shore ◦ Slows ◦ Increases in height

Tsunami warning system Only a few a year Most recent (major) ◦ Indonesia (Dec. 2004) ◦ Japan (Mar. 2011) Seiche