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Explore Earth's moving plates, layers, and tectonic boundaries in this informative guide. Learn about the Earth's distinct inner layers, plate tectonics, and plate movements through engaging visuals and explanations.
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Layers of the Earth • List the layers of the earth in order from the exterior to the interior- in your notebook • Crust • Lithosphere • Asthenosphere • Mantle • Outer core • Inner core
Geologists must use indirect observations Geologists also study- to gather clues about what Earth’s interior is made of earthquakes and rocks that are exposed at Earth’s surface the speed of waves and the paths they take Certain rocks from different places on the Earth’s surface Clues to Earth’s Interior
Earth’s interior has at least 4 distinct layers inner core, outer core, mantle, and crust Earth’s Layers
Inner core Innermost layer Solid-dense-composed mostly of solid iron Hottest part Experiences the greatest amount of pressure Inner Core
Outer core Lies above the inner core Composed mostly of molten metal liquid Outer Core
Mantle Above the outer core Largest layer Flows slowly-similar to putty 82% of Earth’s total volume Mantle
Crust Earth’s outermost layer Thin compared to other layers Contains all features of the Earth’s surface Crust
Lithosphere Plates- rigid, upper part of Earth’s mantle and the crust broken into about 30 sections, or plates Sections of Earth’s crust and rigid, upper mantle that moves slowly around on the asthenosphere Earth’s Plates-Lithosphere
Plate tectonics • Tectonics – • Theory of plate tectonics – • structural deformation of the Earth's crust (Note: prefix “de” • means to undo) • scientific theory explaining how the plates move on the Earth’s surface
Tectonic Plates • http://www.youtube.com/watch?v=nfziy_860GU
Scientific fact, law, theory • Scientific fact- • Scientific law – • Scientific theory – • statement that is accepted as being true. • statement that describes an observed phenomenon but • does not explain how or why it occurs. • statement that explains a complex idea.
Plate boundaries- Boundaries can form- Faults- Where the edges of different plates meet mountains, huge rift valleys with volcanoes, or faults (which cause earthquakes) large fractures in rocks along which movement occurs Plate Boundaries http://www.learner.org/interactives/dynamicearth/drift.html
When plates move apart- New lithosphere and mid-ocean ridges form Volcanic activity Rift valleys Divergent boundary Plates that move apart http://www.learner.org/interactives/dynamicearth/slip3.html
Ocean Basin • Ocean basin • a great depression in the surface of the lithosphere occupied by an ocean • are below sea level. • The Atlantic Ocean has an actively growing ocean basin where as the Pacific Ocean has a actively shrinking ocean basin.
When plates collide Convergent boundary Plates that collide http://www.learner.org/interactives/dynamicearth/slip2.html
3 types of convergent plate boundaries • Continental-continental collisions may cause- • Mountains/shallow earthquakes
3 types of convergent plate boundaries • Continental-oceanic collisions (subduction) may cause- • Earthquake activity, volcanic eruptions, volcanic mountains, tsunamis, ocean trench
3 types of convergent plate boundaries • Oceanic-oceanic collisions (subduction) may cause- • earthquakes, oceanic trench, a chain of volcanic islands
Plate subduction- At a convergent boundary-when one plate sinks underneath another plate Plate Subduction http://www.jclahr.com/science/earth_science/animate/subduct.mov
When plates slide past each other transform boundary Causes faults-which leads to earthquakes Plates that slide past http://www.learner.org/interactives/dynamicearth/slip3.html http://www.learner.org/interactives/dynamicearth/plate.html
Ring of Fire • https://www.youtube.com/watch?v=wJS7hGMr0Ws • http://www.youtube.com/watch?v=YqSJDNi7Qzw&feature=related
Scientists suggest Convection currents Why do plates move?
Here is a simulation of convection in the mantle of the earth. Hot rock (yellow) rises and cool rock (blue) falls. The rock is at 1000 to 2000o C and creeps slowly; the rate of motion is a few centimeters per year (the simulation shows millions of years). The convection occurs because of the slow change of density with depth in the upper mantle, and between the 700 and 400 km discontinuities. As a result, a hot zone of rock at the bottom of one of these zones expands enough so its density becomes less than that of the surrounding rock and it rises, or floats, toward the surface of the earth.
Earth in the Past and Future • https://www.youtube.com/watch?v=uGcDed4xVD4 • https://www.youtube.com/watch?v=38DMH3zP97U