Earthquakes+&+structure+review

Honors Earth Science Objectives // The test is tomorrow Don’t forget to study your Ocean floor map so you will recognize the features in #1 of your objectives (not online). Question 20 is on the test but not online as well- study the 2 handouts given in class. //

__ Structure of the Earth __ 2. What igneous rock makes up the ocean floor? What igneous rock makes up the majority of the continents? // Granite and basalt---Colleen // //** Colleen, which is which? **// granite is continent, basalt is oceanic --amy 3. Which is more dense, oceanic or continental crust? // Oceanic---Colleen // 4. What are the 4 layers of Earth’s interior? inner and outer core, mesosphere, asthehosphere –Nicole
 * PURPLE has been checked by HESMASTER and is correct…mmore answers and corrections are still needed! **

5. What is the Mohorovicic Discontinuity (the Moho) and how did it get its name? // The division between the crust and mantle, from the person who 'discovered' it---Colleen // **__ Andrija Mohorovičić was his name-Nicole __** 6. Which core is liquid? Why not the other core? // Outer, too much pressure---Colleen // 7. What 3 units compose a “plate”? What zone of the Earth’s mantle do plates “float” upon? __Earthquakes__ 8. What are the causes of earthquakes? __Volcanic eruptions, plate shifting, meteorite crashing, and atomic explosions - Megan__ 9. How does a seismograph operate? __A seismograph is attached to the bedrock.__ __  When the earth quakes, a weighted pen swings back and forth illustrating the movement of the earth. – Megan __ Nope the seismograph is attached to the bedrock, and a weighted pen hangs above it. when the earth quakes, due to the law of inertia, the pen remains still and the paper below it shakes. this creates a seismogram. --amy 10. How many seismographs are needed to determine the location of an earthquake? 3 seismographs --amy 11. Compare and contrast each of these seismic waves: P, S, surface ** - ** **P waves are first and compressional, S waves are second and transverse, and surface waves are last and a combination -Nicole and Megan ** 12. What’s the difference between the epicenter and the focus of an earthquake? __The focus is the physical point under groud where the earth quakes. The epicenter is the spot on the crust above the focus. - Megan__ 13. How is an earthquake’s amplitude determined? by the height of  its S waves? – molly the tallest s wave, you measure it from the baseline to the very top. --amy 14. How is the distance to an earthquake determined? -** the closer one is to an earthquake, the larger the waves are-Nicole and Megan ** ** NOOOOOOOOOO ** the distance between the p and s wave - Ron the s-p lag time. the longer the lag time, the farther away the earthquake is. --amy 15. Where and what is the shadow zone? Why does it happen? ** - ** **it is between 105 and ** ** 150 ****degrees away from the epicenter -it is the quiet zone where waves are not detected- it happens ** **because P waves bend -Nicole and Megan  **** 150 is wrong- what is it? ** 140 degrees --amy 16. What are seismic gaps and why are they of interest? seismic gaps are areas that are in need of and overdue for a major earthquake, but no earthquakes are occuring. they are of interest because no one knows the next time an earthquake will occur there. --amy 17. Compare these two earthquake measuring scales: Richter and Mercalli Richter: Earthquake's Energy Based Scale Mercalli: Earthquake Damage Based Scale -Claire 18. Explain liquefaction: what happens and how it happens. liquefaction is when the surface of land basically becomes quick sand. this happens because the water table raises up due to an earthquake and floods and saturates the earth. --amy 19. What are tsunamis? What are the 2 causes? __Tsunamis are large waves (up to 100 ft). They can be caused by eruptions and earthquakes. - Megan__ softer bedrock produces more shaking. harder bedrock produces less. --amy //**
 * lithoshpere, continental crust, and oceanic crust -asthehosphere --Megan and Nicole **
 * //  WHICH S wave? How do you measure it?   //**
 * 1) Why do some areas shake more than others even though they receive the same amount of earthquake energy?   Different Bedrock-Claire
 * // Expand this- which type of bedrock produces more shaking ?