Bell work 11/16 Get a computer Open quizlet Practice vocabulary set 5

QUICK REVIEW… Layers of the Earth Crust (2 types) Mantle Outer Core Inner Core Earth’s crust & the very top solid portion of the mantle form the lithosphere The lithosphere sits on top of the liquid asthenosphere

HOW???

LAW OF UNIFORMITARIANISM Law of Uniformitarianism: States that Earth is an always changing place The same forces of change are at work today that were at work in the past. Some changes are gradual; some changes are fast…some times both!

SINKHOLES http://www.youtube.com/watch?v=RUjo3K_00tY Would you categorize them as a fast change, a slow change, or both? They seem to be getting more common…WHY?

SOME THINGS HAPPEN SLOWLY, WHILE OTHERS HAPPEN QUICKLY, BUT WHAT THEY BOTH HAVE IN COMMON IS A LOT OF THEM STEM FROM MOVEMENT …BUT MOVEMENT OF WHAT???? HINT:

TECTONIC PLATES The Lithosphere is broken into many large and small slabs of rock called tectonic plates and where two plates meet, a lot of changes can occur.

How do the tectonic plates move? The plates move because of convection currents. The hot, soft rock in the mantle rises…then it cools, and sinks. How do the tectonic plates move?

There are 3 types of plate boundaries TECTONIC PLATES 1. Divergent 2. Convergent 3. Transform There are 3 types of plate boundaries

SUBDUCTION What is SUBduction? When one tectonic plate sinks under another plate IT CAN ONLY HAPPEN WHEN… Continental & oceanic plate collide = oceanic plate ALWAYS sinks because it is more DENSE. Oceanic & oceanic plate collide = the more dense plate sinks! What is SUBduction?

DIVERGENT Key word: Divide

DIVERGENT

DIVERGENT Mid-ocean Ridges Rift Valleys Earthquakes What occurs at this boundary? New Crust Forms Mid-ocean Ridges Rift Valleys Earthquakes

REAL-WORLD EXAMPLES : Divergent Boundary Mid-Ocean Ridges like the Mid-Atlantic Ridge

CONVERGENT Key word: Collide 3 types of convergent: Continental-continental Oceanic-oceanic Oceanic-continental

CONVERGENT: CONTINENTAL-CONTINENTAL

CONVERGENT: CONTINENTAL-CONTINENTAL What occurs at this boundary? High mountains Earthquakes

REAL-WORLD EXAMPLES: Continental-Continental Convergent High Mountains like the Himalayas

CONVERGENT: OCEANIC-OCEANIC

CONVERGENT: OCEANIC-OCEANIC What occurs at this boundary? Deep-ocean Trenches Volcanic Islands Earthquakes Hawaii is NOT on a plate boundary!

REAL-WORLD EXAMPLES: Oceanic-Oceanic Convergent Deep-ocean trenches like the Mariana Trench

CONVERGENT: OCEANIC- CONTINENTAL

CONVERGENT: OCEANIC-CONTINENTAL What occurs at this boundary? Deep-ocean trenches Coastal mountains (some are volcanic) Earthquakes

REAL-WORLD EXAMPLES: Continental-Oceanic Convergent Coastal mountains like the Andes Mountains on the coast of South America

TRANSFORM Key word: Slide

TRANSFORM

TRANSFORM What occurs at this boundary? Faults Earthquakes

REAL-WORLD EXAMPLES: Transform Boundary Faults, like the San Andreas Fault in California

PLATE MOTION SIMULATION http://www.sepuplhs.org/middle/iaes/students/simulations/SEPUP_Plate_simulation.swf Simulation of the tectonic plate movement we talked about today!

QUICK REVIEW

Draw and label the 4 main layers of the Earth: ESSENTIAL QUESTIONS Draw and label the 4 main layers of the Earth: What are the 2 type of crust?

Explain why the Earth’s interior is separated into these layers: ESSENTIAL QUESTIONS Explain why the Earth’s interior is separated into these layers: DENSITY

ESSENTIAL QUESTIONS If it is so hot, why is the inner core solid? Because it is under so much intense PRESSURE from the other layers sitting on top of it.

Which 2 layers make up the lithosphere? ESSENTIAL QUESTIONS Which 2 layers make up the lithosphere? Which layer does the lithosphere sit on top of? Crust Mantle (solid upper portion) Asthenosphere

Which layer is broken into tectonic plates? ESSENTIAL QUESTIONS Which layer is broken into tectonic plates? What are the 3 types of tectonic plate boundaries? Lithosphere Convergent, Divergent, Transform

ESSENTIAL QUESTIONS What is the key word that goes with each type of boundary that indicates the type of movment? Convergent = Collide Divergent = Divide Transform = Slide

What is it called when one plate sinks beneath another? ESSENTIAL QUESTIONS What is it called when one plate sinks beneath another? Which plate will sink? Subduction The denser plate/oceanic

What event occurs at all plate boundaries? ESSENTIAL QUESTIONS What event occurs at all plate boundaries? At which type of plate boundary will any mountains occur? Earthquakes Convergent

ESSENTIAL QUESTIONS If new crust is created at divergent boundaries, then why doesn’t Earth get any bigger? SUBDUCTION! As new crust is formed at a divergent boundaries, old crust is being melted down at convergent boundaries where subduction is occurring. New crust is being “created” at the same rate that old crust is being “destroyed.” Earth recycles itself!

PLATE TECTONICS REVIEW Please turn to your note guide from last class so you can reference it during the mini lab activity!

REMEMBER… It is the movement of the tectonic plates that cause the majority of changes on Earth. Some changes happen quickly, while others happen slowly, but none have been more Earth changing than this… HOW?

PANGAEA Scientist Alfred Wegener noticed that Earth’s continents seemed to fit together like a puzzle, so he hypothesized that they were once joined in a single “super continent” called Pangaea which means “all land”

255 MILLION YEARS AGO

152 MILLION YEARS AGO

66 MILLION YEARS AGO THE EXTINCTION OF THE DINOSAURS

PRESENT DAY POSITION

50 MILLION YEARS FROM NOW

150 MILLION YEARS FROM NOW

250 MILLION YEARS FROM NOW

CONTINENTAL DRIFT This led to his Theory of Continental Drift – that although the continents were once joined, they slowly drifted apart! But nobody believed him ☹…why? Wegener’s Evidence: 1. Matching rock layers on different continents 2. Matching fossils on different continents 3. Evidence of climate change – tropical plant fossils in cold places, ice scratches in warm places

SEA-FLOOR SPREADING http://www.youtube.com/watch?v=GyMLlLxbfa4 Harry Hess’ discovery turned the Theory of Continental Drift into the Theory of Plate Tectonics!

SEA FLOOR SPREADING The sea floor spreads apart at divergent boundaries allowing new crust to form…this new crust builds Mid-Ocean ridges The crust closest to the crack is the youngest while the crust further from the crack is older

MAGNETIC REVERSALS Minerals in the magma that rise through the cracks in the sea floor align themselves with Earth’s magnetic poles (North and South) As the rock cools, the minerals stay fixed in this position, like a compass Earth’s poles periodically reverse. The “stripes” of rock along the ocean floor record these reversals.

QUICK REVIEW What is the former “supercontinent” called? Why is it called Pangaea? The idea that the continents had slowly moved is called…? Who was the scientist that proposed the idea of both Pangaea & Continental Drift? Why didn’t people believe him? What did he use as evidence to prove his theory? What LAND FORM was later discovered on the ocean floor that supported his theory?

QUICK REVIEW How is this land form created? This discovery turned the Theory of Continental Drift into the Theory of…? We further discovered that the oldest crust was located…? And the youngest crust was located…? Not only were there age patterns, but patterns of what else? Which scientist is responsible for the discovery of the Mid-Ocean Ridge & Sea- Floor Spreading?

TECTONIC PLATE MAP ANALYSIS

HOT SPOTS! Read Hawaii…How?

HOT SPOTS! – Reading Comprehension What is the Earth’s lithosphere made up of? Where can a volcano form? What plate are the Hawaiian Islands on? Are they at a plate boundary or a hot spot? What is a hot spot? Does a hot spot move? So what is moving? How many islands has this hot spot formed to make the Hawaiian Island chain? Where are there other hot spots?

HOT SPOT VIDEOS – Discovery Education Hot Spots: The Formation of the Hawaiian Islands http://app.discoveryeducation.com/player/view/asset Guid/C485747E-A115-41D6-9D42-D6FFE6CA3914 Yellowstone’s Super Volcano: A Ticking Time Bomb http://app.discoveryeducation.com/player/view/asset Guid/2CE8482D-877D-48D3-A9BB-9A03A86321DA

HOT SPOTS Hot spots occur far from plate boundaries. Magma rises and eventually melts through the crust above it. The plate moves, but the hot spot stays in the same place - creates a series of volcanic islands or volcanoes. Hot spots help measure plate movement.

Conclusion Plate Tectonics & Continental Drift “CONTINENTS ADRIFT” Conclusion Plate Tectonics & Continental Drift http://www.youtube.com/watch?v=HrKTuCDierM

Law of Uniformitarianism Tectonic Plates Subduction Divergent Boundary KEY VOCABULARY TERMS FOR THIS POWERPOINT…BUT DON’T FORGET THE ROCK CYCLE WORDS!!! Crust Mantle Outer Core Inner Core Lithosphere Asthenosphere Convection Current Magma/Lava Law of Uniformitarianism Tectonic Plates Subduction Divergent Boundary Convergent Boundary Transform Boundary Mid-Ocean Ridge Rift Valley Deep-ocean Trench Pangaea Continental Drift Sea floor Spreading Magnetic Reversal Hot Spot