Homeroom Warm Up 11-12-13

1. Homeroom Warm Up11-12-13 On this day in 1815, Women’s Rights Leader Elizabeth Cady Stanton was born. Stanton is well known for her work in the furthering of women’s rights. Why do you think women were not allowed to vote for such a long time?

2. Science Warm Up11-12-13 Rocks in the Earth's mantle contain a higher percentage of _______ and _______ than do rocks in the Earth's crust. a. magnesium and oxygen b. iron and magnesium c. iron and silicon d. silicon and oxygen

3. Academic Enrichment Warm Up Which of the following lists the Earth’s layers in order from coldest to hottest in temperature? a. outer core, mantle, inner core, crust b. mantle, crust, inner core, outer core c. inner core, outer core, mantle, crust d. crust, mantle, outer core, inner core

4. Homework Page 407 in textbook

5. What is Plate Tectonics? GLE 0707.7.4 Explain how earthquakes, mountain building, volcanoes, and sea floor spreading are associated with movements of the earth’s major plates.

6. Earth’s Layers The Earth's rocky outer crust solidified billions of years ago, soon after the Earth formed. This crust is not a solid shell; it is broken up into huge, thick plates that drift atop the soft, underlying mantle.

7. Plate Tectonics • The Earth’s crust is divided into 12 major tectonic plates which are moved in various directions. • This plate motion causes them to collide, pull apart, or scrape against each other. • Each type of interaction causes a characteristic set of Earth structures or “tectonic” features. • The word, tectonic, refers to the deformation of the crust as a consequence of plate interaction.

8. World Plates

9. What are tectonic plates made of? • Plates are made of rigid lithosphere. The lithosphere is made up of the crust and the upper part of the mantle.

10. What lies beneath the tectonic plates? • Below the lithosphere (which makes up the tectonic plates) is the asthenosphere.

11. Plate Movement • “Plates” of lithosphere are moved around by the underlying hot mantle convection cells

12. Divergent Convergent Transform Three types of plate boundary

13. Spreading ridges As plates move apart new material is erupted to fill the gap Divergent Boundaries

14. Sea Floor Spreading • Mid Ocean Ridges – underwater mountain chains that run through the Earth’s Basins • Magma rises to the surface and solidifies and new crust forms • Older Crust is pushed farther away from the ridge

15. Age of Oceanic Crust Courtesy of www.ngdc.noaa.gov

16. Iceland: An example of continental rifting • Iceland has a divergent plate boundary running through its middle

17. Convergent Boundaries • There are three styles of convergent plate boundaries. Plates that are colliding • Continent-continent collision • Continent-oceanic crust collision • Ocean-ocean collision

18. Continent-Continent Collision • Forms mountains,e.g. European Alps, Himalayas

19. Himalayas

20. Continent-Oceanic Crust Collision • Called SUBDUCTION

21. Subduction • Oceanic lithosphere subducts underneath the continental lithosphere • Oceanic lithosphere heats and dehydrates as it subsides • The melt rises forming volcanism • E.g. The Andes

22. Ocean-Ocean Plate Collision • When two oceanic plates collide, one runs over the other which causes it to sink into the mantle forming a subduction zone. • The subducting plate is bent downward to form a very deep depression in the ocean floor called a trench. • The worlds deepest parts of the ocean are found along trenches. • E.g. The Mariana Trench is 11 km deep!

24. Transform Boundaries • Where plates slide past each other Above: View of the San Andreas transform fault

26. Volcanoes and Plate Tectonics… …what’s the connection?

27. Pacific Ring of Fire Volcanism is mostly focused at plate margins

28. - Subduction - Rifting - Hotspots Volcanoes are formed by:

29. Pacific Ring of Fire Hotspot volcanoes

30. What are Hotspot Volcanoes? • Hot mantle plumes breaching the surface in the middle of a tectonic plate The Hawaiian island chain are examples of hotspot volcanoes. Photo: Tom Pfeiffer / www.volcanodiscovery.com

31. The tectonic plate moves over a fixed hotspot forming a chain of volcanoes. The volcanoes get younger from one end to the other.

32. Earthquakes and Plate Tectonics… …what’s the connection?

33. As with volcanoes, earthquakes are not randomly distributed over the globe • At the boundaries between plates, friction causes them to stick together. When built up energy causes them to break, earthquakes occur. Figure showing the distribution of earthquakes around the globe

34. Where do earthquakes form? Figure showing the tectonic setting of earthquakes

35. Plate Tectonics Summary • Name the 3 main layers of the Earth • What is a tectonic plate? • What was Pangea? • What is Sea-Floor spreading? • Name the three different types of plate boundaries and one location on Earth for each one

36. Science Closure11-12-13 Divergent plates move _________ from each other. This causes _______ to form as well as mid-ocean ridges. a. towards, rifts b. away, rifts c. away, aquifers d. towards, mountain ranges

37. Academic Enrichment Closure Most tectonic plates move at rates of a. centimeters per year. b. meters per year. c. centimeters per second. d. meters per second.