Our Dynamic Earth Unit Unit 5

Transcription

1 EARTH SCIENCE REGENTS - SOTO Our Dynamic Earth Unit Unit 5 Mr. Soto - Key 1/1/2013 Our Dynamic Earth

2 Vocabulary List 1 Directions: Define each vocabulary word provided below. You may have to use your Earth Science textbook, dictionary or the internet in your textbook. Aesthenosphere mid-ocean ridge conduction Moho boundary continental drift plate tectonics convection rift valley convergent boundary ring of fire core sea floor spreading curst subduction zones Page 2 of 26

3 divergent boundary transform boundary inner core trench mantle Page 3 of 26

4 Vocabulary List 2 Directions: Define each vocabulary word provided below. You may have to use your Earth Science textbook, dictionary or the internet in your textbook. earthquake Pangea epicenter p-wave fault s-wave focus seismic wave hot spot seismograph hot spot seismograph intensity seismogram island arc seismologist Page 4 of 26

5 magnitude tsumani origin time Page 5 of 26

6 I. Evidence of Crustal Changes A. Deformed Rock Structure sedimentary forms starting in a a normally in a horizontal position. Any change from the horizontal positions is evidence of minor crustal change Normal undisturbed layer (no motion) 3. Page 6 of 26

7 B. Fossil Evidence uplift normal environment subsidence/sinking 1. Marine fossils found at high elevations suggest uplifting. Shallow water marine fossils found at great ocean depths suggest II. Plate Tectonics A. Earth s Structure 1. Earth s Interior _subsidence/sinking. crust mantle 2800 outer core inner core Page 7 of 26

8 a. 2. Earth Surface Oceanic Lithosphere Continental Crust Upper Mantle Crust Aesthenosphere b. Density of: 1. ocean (water) 1.0 g/cm 3 2. granite (continental crust) 2.7 g/cm 3 3. basalt (ocean crust) 3.0 g/cm 3 4. rigid upper mantle g/cm 3 5. asthenosphere g/cm 3 c. Lithosphere = _crust+_upper mantle d. Aesthenosphere the plastic layer below the lithospere in Earth s mantle. e. Thickness of: 1. Continental Crust_30-70km, 20-60mi. 2. Ocean Crust_7-10km, 3-6mi. B. Theory of Continental Drift 1. Alfred Wegener _proposed the theory of continental Drift in the Early 1900 s 2. He proposed that approx. 200mya, all the contents existed as one large land mass which he called Pangaea. 3. Evidence for Continental Drift (5 Clues) Page 8 of 26

9 1. Coastline of the continents for example, the earth coast of South Americas fits well with the west coast of Africa like pieces of a giant jigsaw puzzle. North America Africa India South America Australia Antartica 2. Fossil Clues fossils of ancient life forms Mesosaurus were discovered in widely separated continents. It was small freshwater reptile. It s fossils are found in Africa and South America. Page 9 of 26

10 Glossopteris Map Key It was an ancient seed fern (with very large heavy seeds). It s fossils are found in Africa, India, Australia, Antartica, South America 3. Rock Clues a. The Appalachian Mountains of the eastern US are geologically similar to the mountains in the Greenland and western Europe, which include the Caledonian Mountains of Scotland. b. Structure, age, and mineral content of rocks are similar on the coasts of eastern South America and western Africa. 4. Climate Clues a. Coal, which forms from plants that grow in warm swampy environments, is found today in the colder climates of North America and Antarica. a. NY b. Coral Limestone, containing the remains of coral, which once lived in warn seas, is found today in northern latitudes such as S. c. Ancient rocks of the same age near the equator in South America, South Africa and other southern landmasses show evidence of glaciations. Page 10 of 26

11 C. The Theory of Seafloor Spreading 1. Topography of the Ocean Floor Seamount volcano peak ~1000 meters from ocean floor Abyssal plain - very flat area of ocean floor Rift Valley two plates separating by moving in opposite directions Mid-ocean ridge underwater mountain range Guyote Trench deep and narrow depression in the ocean floor ex.: Marianis trench Continental Slope Continental Shelf Page 11 of 26

12 2. Evidence of Sea Floor Spreading 1. Age Evidence as the distance from the ocean ridgeincreases, the age of the rock increases. 2. Magnetic Evidence (Paleomagnetism) magnetic clues form the ironbearing basalt rock of the ocean floor supports the theory of seafloor spreading. Page 12 of 26

13 C. The Theory of Seafloor Spreading (continued) 1. The theory of Plate Tectonics states that Earth s lithosphere (crust +upper mantle) is divided into sections called lithosphere plates. Eurasia Eurasia North America Padific Africa Indian South America India Nazca Antartica Antartica Key Major Plates 1. North America 5. Pacific 2. South America 6. Nazca 3. Eurasia 7. Antartica 4. Africa 8. Indian 2. Plate Motion The theory of Plate Tectonics states that these lithospheric plates are in motion and float or ride on the asthenorsphere. 3. Direction of Plate Movement The movement and interaction of tectonic plates creates 3 types of plate boundaries: the arrows on the map (page 8) show the relative motion. Plate Boundaries Movement Arrows on Map Divergent Plates move away from each other Converget Transform Plates move toward each other Plates move lateral past each other or sideways Page 13 of 26

14 4. Types of Plate Boundaries A. Divergent Plate Boundaries two plates are moving apart 1. Ocean (example) Mid-Atlantic Ocean Ridge 2. Continental (example) Great Rift Valley of Africa B. Convergent Plate Boundaries Where two plates come together or collide. 1. Oceanic-Continental (example) Pacific (ocean plate) sub ducts under South American continental plate. subduction slab Page 14 of 26

15 2. Oceanic-Oceanic (example) 3. Continental-Continental (example) - Page 15 of 26

16 4. Transform Plate Boundaries (example) - 5. = the driving force beneath plate tectonics. Hot dense material form deep within the Earth s mantle rises. When this material cools near the surface, it becomes dense and sinks. The resulting convective flow of this material in the mantle lithospheric plates across the surface of the Earth. Page 16 of 26

17 III. Earth Quakes A. - the branch of science that studies earthquakes. B. Earthquake Regions on Earth Page 17 of 26

18 C. Earthquake Waves 1. Origin and map location Focus = Epicenter = P waves 2. Types: Proper Name Travel Speed Direction of motion S waves Page 18 of 26

19 3. measures and records earthquake waves. Page 19 of 26

20 E. Locating the Epicenter of an Earthquake 1. Houston Texas 2. Chicago, Illinois 3. Seattle, Washington Seismograph Station Arrival Time P-wave S-Wave Difference in Arrival time Distance to Epicenter Page 20 of 26

21 Reference Table Page Page 21 of 26

22 Page 22 of 26

23 F. Earthquake Waves and Earth s Interior 1. Analysis of seismic waves (P and S waves) has led scientist to infer the interior structure of the Earth. 2. a. P waves travel through and. b. S waves can only travel through. 3. Earth s structure/interior is divded into the crust, mantle, outer core and inner core. 4. Key P waves= S waves= Reference Table Page Page 23 of 26

24 G. Measuring an Earthquake 1. - a scale used to express the strength or energy an earthquake releases by assigning a number from 1 to 10. (Each of the numerical steps represents a ten-fold increase in the amount of energy; for example, a reading of 3 indicates 10 more energy than a reading of 2). Earthquake Occurrences Richter Scale Number Expected Per Year 1.0 to 3.9 > 100, to 4.9 6, to to to to 8.9 < a scale used to show the damaged caused by an earthquake by assigning a number from I to XII. Step I III V VII IX XII Some Steps In The Mercalli Scale Of Earthquake Damage Extent of Damage The earthquake is felt by only a few people near the epicenter. The earthquake is felt in buildings, usually only upper floors. Windows and fragile objects are broken. People run out of buildings, some masonry breaks. Cracks for in the ground, and all buildings are damaged. Objects are thrown into the air; all structures are destroyed. Page 24 of 26

25 H. Earthquakes cause other disasters = gigantic sea waves. Charcteristics: speed = height = Page 25 of 26

26 IV. Volcanoes A. Volcanic Regions on Earth = region of volcanoes that encircle the pacific B. Hotspots Page 26 of 26