The Changing Face of Earth Plate Tectonics- Putting it all together

Objectives SW explain the underlying mechanism of plate movement. Interpret synthesized data for plates to develop generalized patterns of plate interactions. Be able to categorize plate boundaries as convergent, divergent or transform Be able to justify claims with evidence based on physical or geologic features

Detailed map of modern plates from USGS http://pubs.usgs.gov/gip/dynamic/slabs.html

Essential Questions What is a plate? How/why do the plates move? What types of interactions can plates have? Which evidence patterns show up with which interactions? I am going to read an excerpt to you from the USGS, your job is to listen and record answers to these questions on your notes sheet

Has the Earth’s surface always looked like it does now? What was different or How has it changed? Got Evidence?

CEI

Claim At various points in time the landmasses of Earth have had numerous arrangements. At one point they were all together and formed a giant landmass called Pangaea.

Evidence Matching reptile fossils found in South America and Africa Identical species of ferns found in all southern continents. Rocks in SW Africa and SE Brazil were distinctively identical, and their age the same.

Interpretation Due to continental drift our continents are where they are today, and continue to drift apart or toward each other. The underlying mechanism of both continental drift and the movement of the plates is convection currents.

Think, Pair, Share & Write How do you think or what do you think causes the plates to move? Explain the process. 45 seconds to think… 30 seconds to share 45 seconds to write Three share outs

Proposed model for plate movement by convection currents, Heat rises from the liquid Outer Core heating the Mantle causing it to rise, as the mantle encounters the solid and cool crust it starts to cool and pulls the lithosphere. Thus causing plate movement Proposed model for plate movement by convection currents,

The plates make up Earth's crust Rising convection currents in the soft mantle below propel them along like a conveyor belt.

The movement of the plates creates three types of tectonic boundaries.

Types of Boundaries Depart from each other Plates move from a fraction of an inch to about 5 inches a year. A plate moving at 2 inches a year will travel about 30 miles in a million years. Convergent plates come together- move toward one another. They Collide!! Divergent plates move apart. Depart from each other Transform plates move sideways in relation to each other. Sliding!!

Convergent Plates 3 Types of Convergent Plates: Continental-Continental Oceanic-Continental Oceanic-Oceanic

Convergent Plates: Continental--Continental Where continental plates collide, the crust crumples and buckles into mountain ranges (Himalayas)

Himalaya Mountain Range

Convergent Plates: Continental--Oceanic Ocean plate dives under the continental plate in a process called subduction. Overlying plate lifts up to form mountain ranges. The subducting plate melts creating active volcanoes. A deep trench runs right along the boundary Ca

Convergent Plates: Oceanic--Oceanic Subduction Uplift (Islands form in a volcanic arc) Trench forms at boundary

Divergent Plates Divergent boundaries occur when plates move away from each other (Depart!) “Seafloor spreading” in the oceans creates new rock: Under water mountain ranges form as magma rises when a crack forms Rift Valleys are formed with oceanic ridges on either side. On land, giant troughs may form where plates are tugged apart.

A cloud of hydrothermal fluids streams from a black smoker, or mineral chimney, along the Mid-Ocean Ridge off the west coast of Mexico. Black smokers are common to spreading zones in plate boundaries

Transform Boundary Plates slide past each other. Pressure builds up and is released when the plates move. This causes a lot of earthquakes! California’s San Andreas Fault

Transform Plates

Where will San Francisco be in the future?

Not at plate boundaries: HOT SPOTS: Area of the earth where a plate moves over a magma chamber/hot spot Hawaii:

Yellowstone National Park

Which type of boundary? 2. _____________ 1. _____________ 3. _____________

What does the future hold? Think about it for a minute… Make 1 Claim about what the future Earth may look like and use Evidence from the above map to support it. Then Interpret your claim based on what you have learned regarding plate tectonics.

HOMEWORK Study for your quarter exam Topics Scientific Method (hypothesis,variables, purpose, error) Graphing Topo Maps Formation of Earth and Evidence Plate Tectonics Make your notecard!!!!!!!