Topic 12

1. Topic 12 Earths Dynamic Crust and Interior

2. Lithosphere: Layer of rock that forms the outer shell of the earth Crust: The upper part of the lithosphere

3. Small Scale Crustal Changes Law of original Horizontality: Sedimentary rocks form flat horizontal layers

4. The Four ways that Rock Layers are Changed 1) Folding: Compression causes layers to bend 2) Tilting: Layer of strata get tipped

5. The Four ways that Rock Layers are Changed 3) Faulting: Rocks are displaced along a crack called a fault 4) Uplift: Rock layers get pushed up many meters

6. Earthquakes and Igneous Activity Including Volcanoes quake Earthquake: Natural rapid shaking of the earth The stored energy in the ground is released as seismic waves Focus: Place where the earthquake originates Epicenter: Place on earth’s surface directly above focus Fault: Plane where the rock breaks Example

7. Earthquakes and Igneous Activity Including Volcanoes Seismograph: Instrument used to detect and measure quakes How it Works Again Seismogram: Actual recording of the quake

8. 3 Types of Earthquake Waves 1) P-waves (primary): Compression wave that vibrates in the same direction as particles 2) S-waves (secondary): Shear wave that moves perpendicular to the particles 3) L-waves (surface): Travel on surface and cause the damage

9. Properties of Seismic Waves -P-waves are fastest and arrive at the seismograph 1st -Waves travel faster in more dense material -Waves travel faster as pressure is increased -P-waves travel through solids, liquids and gasses -S-waves only travel through solids

10. Location of an Epicenter The location of any earthquake can be found by knowing the distance from the epicenter to three seismic stations. Process 1) Find the time difference between P and S waves 2) Mark the time difference on scrap paper 3) Use ESRT to find distance 4) Repeat for 2 more seismograms

11. Location of an Epicenter What does the distance from one seismograph tell us? The quake was somewhere on the circle What does the distance from two seismographs tell us? Narrows it down to 2 possibilities What does the distance from one seismograph tell us? Exact location

12. Finding the Origin Time of Earthquakes 1) Use the distance to determine travel time 2) Subtract travel time from arrival time AT 10:27:35 TT - 7:42 AT 15:26:12 TT - 3:20 10:19:53 15:22:52

13. Magnitude of Earthquakes Measure of the intensity of an earthquake Mercalli Scale: Rates the effects of the earthquake Richter Scale: Measuresmagnitude of actual energy released Tsunami: Seismic sea wave triggered by a quake How they work

14. Igneous Activity and Volcanoes Volcano: Mountain made of extrusive igneous rocks Volcanic Eruption: Giving off of gasses lava and rock Zones of Crustal Activity Ring of Fire: Area of volcanic activity surrounding the Pacific Where are other areas of activity located? Plate Boundaries Mount Saint Helens Pyroclastic Flow

15. A Model of Earth’s Interior Scientists use seismic waves to create a model What happens to pressure as you go from crust to core? What happens to temperature as you go from crust to core?

16. Zones of the Earth Lithosphere Thinnest layer (shell on a hard boiled egg) 2 Types of Crust 1) Continental Crust: Rock that makes up the continents Composition: Granite Density: 2.7 g/cm3 2) Oceanic Crust: Rock that makes up the ocean floor Composition: Basalt Density: 3.0 g/cm3

17. Zones of the Earth Moho: The interface between lithosphere and the mantle Asthenosphere: Upper mantle (like silly putty) able to flow Mantle: Layer of rock between the Asthenosphere and outer core Makes Up 80% of Earth’s Volume Core: Central part of the earth 2 Cores 1) Outer Core 2) Inner Core Composition: Composition: Iron and Nickel Iron and Nickel State of Matter: State of Matter: Solid Liquid

18. NO WE ARE NOT GOING TO WATCH THE MOVIE THE CORE BECAUSE IT IS DUMB

19. Also Dumb!!

20. Plate Tectonic Theory What is a plate? Large section of the lithosphere The lithosphere of the earth is made up of 12 major Plates How fast do these plates move? 3 to 10 cm/yr.

21. Evidence of Plate Tectonics Fossils: Land fossils match on different continents Geology: Rock types and ages match on different continents Puzzle: Continents fit together like a puzzle

22. The Driving Force Behind Plate Movements

23. The Three Types of Plate Boundaries 1) Divergent: Plates move away from each other a.) Midocean ridges: Mountain ranges in the middle of oceans b.) Rift valleys: Deep valleys formed from separating plates How it happens

24. The Three Types of Plate Boundaries 2) Convergent: Plates are coming together 3 Varieties of Convergence Oceanic-Oceanic: 2 oceanic plates collide -Volcanic island arcs -Destruction due to subduction

25. The Three Types of Plate Boundaries b) Oceanic-Continental: Collision of oceanic and continental plates -Mountain ranges and volcanoes -Deep sea trenches

26. The Three Types of Plate Boundaries c.) Continent-Continent: 2 continental plates collide -Mountain ranges -Earthquakes Creation and Destruction

27. The Three Types of Plate Boundaries 3.) Transform Plate Boundaries: Plates grind horizontally -Deformation of rock and many quakes San Andreas Fault

28. Hot Spots Hot Spots: Major volcanic activity in the middle of plate -Caused by concentrations of radioactive elements -Ex: Hawaii and the Galapagos How do they form

29. Effects of Plate Tectonics Appearance of Continents: Fit together Features of Landmasses: Fossils on different continents, coal bed correlation, tropical fossils in NYS, marine fossils on mountains Heat and Age Patterns Age: Edges of the ocean is the oldest, new material at MOR Heat Patterns: Rock gets cooler and denser towards the continents Sea Floor Spreading Magnetic Patterns Polarity -Poles have reversed throughout history