Week of January 23, 2017

*Sea-Floor Spreading & Convection Monday

Wegener’s Theory Everyone agreed that Wegener’s evidence was compelling, but he couldn’t provide a mechanism for continental movement. In the 1960’s, Harry Hess used new technology and radar to make a discovery to help support Wegener’s Theory.

*Sea-floor Spreading *Henry Hess discovered that the ocean floor has both trenches and mid-ocean ridges. Trench: long ditch Mid-ocean ridge: long mountain line *Hess proposed that hot material below Earth’s crust rises toward the surface at the mid-ocean ridges. *Hess’s discoveries provided a possibility for how the crust could move.

*Evidence Sea-floor Spreading In 1968, scientists aboard the research ship Glomar Challenger began gathering information about the rocks on the seafloor. *Scientists found that the youngest rocks are located at the mid-ocean ridges.

Age of Oceanic Crust

Possibility for Movement Sea-floor spreading provided an explanation for how the continents moved. The magma which pushes up at the mid-ocean ridge provides the new land pushing the plates. Both Hess’s discovery and Wegener’s continental drift theory combined into what scientists now call the Theory of Plate Tectonics.

How does sea-floor Spreading occur? So, sea-floor spreading exists. How does it happen? It’s still giant slabs of oceanic and continental crust moving around… how!?

*Plate Tectonics Tuesday

Tectonic Plates Map Directions: Cut out the map. Glue it into your notebook as a flap. (You’ll have to write underneath.)

Tectonic Plate Names Note: You should know the names of the major plates and be familiar with the minor plates. These names will help us discuss plate boundaries.

*Tectonic Plate Boundaries Directions: Cut along the solid lines; fold along the dotted. Glue this into your notebook like a flipbook. Open the book and take notes. Convergent Boundaries Tectonic plates collide into each other Often causes mountains Called “Destructive” because crust crumbles as the plates collide Divergent Boundaries Tectonic plates pull away from each other Often causes rifts Called “Constructive” because magma reaches the surface and cools into new crust Transform Boundaries Tectonic plates slide past each other Causes earthquakes and faults Called “Destructive” because crust crumbles as the plates grind

Plate Tectonics in Action Wednesday – DE Video & Video Worksheets

*Plate Boundaries & Landforms Thursday

Divergent Convergent Transform

Above ground volcanoes in South America Great Rift Valley in Africa Mid-Atlantic Ridge in the Atlantic Ocean Pulling away from each other Continental Crust – Rift Valleys Oceanic Crust – Sea-floor Spreading Sliding past each other Earthquakes Fault Lines San Andreas Fault in California Colliding into each other Indo-Australian Plate & Eurasian Plate converge to form the Himalayan Mtns. Mountain Building Newer Older plate subducts under the newer. Volcanoes Underwater volcanoes Older Above ground volcanoes in South America Oceanic crust subducts under the continental crust. Volcanoes Continental Oceanic

BrainPop: Plate Tectonics Friday – Video, Challenge, & Quiz (Graded)