Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Earth Science Lithospheric Plate Boundaries Due at the end of the school day TOMORROW (Friday)! You may turn it in today if you are finished. #15: Plate Boundaries Review Pg. 247 #’s 1-3 Pg. 244 #’s: - 8 (a) & (b) - 9 (a) - 10 (a) & (b) - 11 (a), (b), & (d) Questions are found in the BLACK TEXTBOOK Quiz 6 study guide What is a fault? 3 types of plate boundaries Result of convergent boundaries C vs. C O vs. C O vs. O Modern evidence of continental drift What is subduction? Describe Sea-floor spreading What is the MOR? IV. EARTHQUAKES “Let’s rock & roll!” A. Earthquake 1. Definition: shaking of Earth’s crust caused by the sudden release of built up energy. ~ every 30 seconds ~3,000 annually strong enough to cause damage ~20 annually cause severe damage ~Caused by stress (force that changes the rocks shape or volume.) http://www.youtube.com/watch?v=ZxPTLmg0ZC w Stresses U.S. Seismology Seismic Activity in the West World Semisolgy B. Parts of a Earthquake 1. 2. Focus- point beneath Earth’s surface that is under stress and breaks. Epicenter- point on the earth’s surface directly above the focus. C. Seismic Waves- carry energy from Earthquake away from focus 1. P wave (primary) 1st to be recorded Travel through all materials (rock, fluids, air) Move straight along ground in an accordion fashion like a spring or slinky b.) S wave (secondary) 2nd fastest wave Move side to side & up and down Only move in solids c.) Surface wave (product of P & S waves) Move very slow Move like ocean waves Very destructive! http://www.pbs.org/wnet/savageearth/earth quakes/index.html D. Measuring Earthquakes We cannot predict the time or location of an earthquake, but we can record their data after they occur. 1. Mercalli Scale- level of damage 2. Richter Scale- measures earthquake’s magnitude (size of earthquake/amount of seismic waves) 2. Richter Scale- measures earthquake’s magnitude (size of earthquake/amount of seismic waves) a. seismograph- instrument used to measure Earth’s movements. b. the pattern of seismic waves produced by a seismograph = seismogram Earthquake “The Great Chilean Earthquake” May 22, 1960 near Valdivia, in southern Chile magnitude of 9.5 "largest earthquake of the 20th Century". The earthquake produced a powerful tsunami that traveled at a speed of about 200 miles per hour across the Pacific Ocean. The wave killed 61 people in Hawaii, 138 in Japan and 32 in the Philippines. The star marks the location of the epicenter and the numbers on the contour lines are travel times in hours for the wave front. Image by NOAA An aerial view of damage caused along the coast of Chile by the tsunamis. This scene shows part of a coastal community where homes were torn from their foundations and tossed about by the waves. Damage was near total in these areas. Photograph of buildings in Valdivia, Chile damaged by the earthquake. This photo shows houses located on an area underlain by fill. They slid downhill when the waterlogged soil beneath them failed Before and after photographs of the village of Queule. This area was damaged by land subsidence and was inundated by the tsunami. Houses, boats and uprooted trees were washed as much as a mile inland by a 13 foot-high tsunami This view parallels what used to be a waterfront street in the community of Quellon. This area subsided about six feet during the earthquake, flooding houses at low elevation. photo of a tsunami-damaged area in Hilo, Hawaii. The area in the foreground was cleared of heavy machinery, mill rollers and metal stocks that were strewn about by the wave U.S Comparison Alaska- 1964 magnitude of 9.2 struck Prince William Sound aftershocks and with a magnitude greater than 6.0 over 10,000 aftershocks total Caused buildings to shake as far as Seattle, Washington FINDING AN EPICENTER Plate Tectonics Sketch the Diagram on pg. 152-153 in the red text book into your composition book. Label the following: Convergent, Divergent and Transform boundaries Ocean and Continental Crust Rift, Lithosphere, Subduction Zones, Convection currents. Missoula San Francisco Denver Guide to reading a seismogram Use the data from the recording stations: Station A: San Francisco, California P-Wave arrival 3:02:20 S-Wave arrival 3:06:30 What is the time difference between P and S wave arrivals? Use the data from the recording stations: Station B: Denver, Colorado P-Wave arrival 3:01:40 S-Wave arrival 3:05:00 What is the time difference between P and S wave arrivals? Use the data from the recording stations: Station C: Missoula, Montana P-Wave arrival 3:01:00 S-Wave arrival 3:03:00 What is the time difference between P and S wave arrivals? Difference in arrival times: San Francisco: 4:10 Denver, Colorado: 3:20 Missoula, Montana: 2:00 MOVE THE PAPER UNTIL THE TWO TICK MARKS LINE UP WITH THE P AND S CURVES WHEN TICK MARKS LINE UP, GO STRAIGHT DOWN AND READ THE EPICENTER DISTANCE EPICENTER DISTANCE OF 2800 KM EPICENTER DISTANCES San Francisco: 4:10 2,800km Denver, Colorado: 3:20 2,000km Missoula, Montana 2:00 1,100km Recording Board Difference in arrival times: San Francisco: 4:10 =2,800km 5,000 4,000 3,000 2,000 1,000 Open your compass to the EXACT distance on the scale. . 2,800km . . 2,000km Triangulation http://video.nationalgeographic.com/video/player/e nvironment/environment-naturaldisasters/earthquakes/inside-earthquake.html Bellringer: Earthquakes Complete #1-3 in your comp. book 1. Describe how you determine the epicenter of an earthquake using a seismogram. Find the lag time, use the S-P graph to determine the distance, draw the radius around the seismic station 2. What does a time-travel (S-P) graph tell us about an earthquake? The distance we are from the quake 3. Explain how you find the amplitude of an S wave on a seismogram. Determine the tallest peak or dip of the wave