APES 11/30 and 12/1 Please take out your plate tectonics lab and map Log in to a computer Grab your folder Got a soil sample? Label it and put in by the fume hood

Folder Grading 1.2 current events (both stamped): 20 pts. 2.Unit 3 FRQs: 10 pts. 3.Wolf FRQ: 5 pts. 4.Biome Spreadsheet: 5 pts. -Graded (mostly!) on completion since you correct your FRQs in class

Learning Targets

Plate Tectonics HW Review 5 min: check in with your group to get questions answered. I’ll be circulating! Put your gold lab in the inbox and your map in your folder.

What is on AP test: I. Earth Systems and Resources (10-15%) A. Earth Science Concepts (Geologic time scale; plate tectonics, earthquakes, volcanism; seasons; solar intensity and latitude) B. The Atmosphere (Ch. 4) C. Global Water Resources/Use (after break) D. Soil and Soil Dynamics (later this week)

What’s Inside the Earth?

Earth Profile by Texture LITHOSPHERE Hard & brittle Earth’s Crust +Upper- most mantle “Plates” ASTHENOSPHERE Highly Viscous 2 nd Upper-most mantle Convection current that carries the plates

Ocean and Continental Crust OCEAN crust Denser Thinner Eventually subducted Relatively young CONTINENTAL crust Less dense Thicker Rarely/never subducted Oldest crust on Earth

Theory of Continental Drift Continents were formed from the drifting apart of one super continent Pangaea Found evidence of similar fossils and geological formations on different continents The shape of continents also seemed to “fit” together

Fossil & Geologic Evidence Big flaw with theory: How did the continents actually move?

Theory of Plate Tectonics Outer “shell” of Earth is broken into plates (lithosphere) Plates are carried by convection cells in asthenosphere Moving plates collide, diverge, or slide by each other Explained Alfred Wegener’s Theory of Continental Drift

Convection cells in asthenosphere (upper mantle) cause sea floor spreading

Convergent Boundaries 1. Continental/Oceanic Denser ocean crust is subducted under. Deep trench, strong earthquakes Energy of subduction often creates volcanic mountain range on continent Examples: Andes Mts. Cascade Mts.

Convergent Boundaries 2. Oceanic/Oceanic Slower plate is subducted (pulled under) Outcome = volcanic islands, strong earthquakes, tsunamis, deep trenches Ex: Aleutian islands (Alaska), Hawaiian Islands, Japan, Southeast Asia uter/flash/conv ergance2.htm

Hot Spots Magma flows from a weak spot/vent in the crust creating a volcano Crust above the vent is moving Forms a chain of land that varies in age down the chain (i.e. Hawaii)

Why is Nihau the oldest Hawaiian Island? Hawaii the youngest? What island still has active volcanoes? In a hundred years will it still have an active volcano? Why or why not?

Types of Volcanoes Composite = Alt. layers of lava flows, ash, and cinder Infrequent but explosive eruptions Usually large and conical Occur along subduction zones Ex: Mt Hood, Mt. Rainier, Mt Shasta

Cinder Cones Built above a vent from lava fragments called “cinders” ejecting from the vent Steep, small eruptions Very common, form in groups or on the edges of shield volcanoes Craters of the Moon National Monument in Idaho

Shield Volcano Built by large, non-explosive lava flows Gently sloping Formed at hot spots, sea floor spreading, and occasionally subduction zones Ex: Big Island- Mauna Loa, Mauna Kea, Kilaeua

Convergent Boundaries 3. Continental/Continental Continental Crust is light, so no subduction Instead, piles of crumpled, folded crust = tall mountains Examples: Himalayan Mts., Appalachian Mts., Alps

Himalayan Formation the-himalayas

Divergent Boundary Normal Fault Mostly below the ocean Sea Floor Spreading - Forms new crust Example: Mid Atlantic Ridge, Rift Valley in Africa

Great Rift Valley- Africa

Age of Seafloor

Transform Plate Boundaries 2 plates sliding in opposite directions E.g. San Andreas Fault

Faults Fractures in crust Occur along plate boundaries, but occasionally occur in the middle of a plate Rigidity of crust builds up tension; eventually slippage occurs to release tension  this is an earthquake

What causes the seasons? Earth’s Tilt: 23.5 degrees. The rotation of the earth around the sun. Direct sunlight vs. Indirect sunlight.

Solar Intensity vs. Latitude Lower latitudes are nearest to the equator They always receive more intense sunlight than “higher” latitudes N and S hemispheres differ in solar intensity depending on season

Test Corrections! Multiple Choice only –Show new content learning All retakes and corrections due Friday –Retakes for scores of 22 and below Done early? Find the Ch. 8 assignment and start Module 24.

Due Next Time Gold Day: Module 24 (see online assignment!)