Plate tectonic theory (8.9AB) to describe the historical development of evidence that supports plate tectonic theory AND relate plate tectonics to the formation of crustal features

Alfred wegener Believed the continents were moving since Greenland’s coordinates had changed. He collected evidence from around the world.

Evidence of climate change Examine your map of continent change over time to answer the questions below: How does the theory of Continental Drift provide an answer to how tropical plants could have grown on Antarctica? Evidence of glaciers have been found in the arid regions of Africa. Why would the existence of glaciers in this area be evidence of climate change?

Mapping ocean floor In the 1950’s, four discoveries led to the plate tectonics theory:  sonar, or echo sound devices, to map the ocean floor

Mapping the seafloor

Divergent continental/continental Great Rift Valley in Africa

Divergent oceanic/oceanic Using page 333, let’s read and take a few bullet notes about further evidence found about possible plate movement Hess

Convection in the Earth Using page 325, read convection in earth’s mantle Highlight the layers of the earth Look at figure 10 caption. Answer the two questions in your ISN.

Where are the plates located? plates Convection currents

Evidence: seafloor spreading Using page 333, let’s read and take a few bullet notes about further evidence found about possible plate movement Hess

Where is new rock? Old rock? Old rock gets subducted under the coastline New rock forms pushing out old rock recycling

Paint your nail and use the magnet to see if you can see a stripe effect left behind Magnetic stripes - magnetic poles switch causing iron in the rocks to change directions occurring about every 1 & 1/2 million years

Magnetic stripes Describe the pattern that occurred in your model. How does this pattern of alternating polarity support the theory of plate tectonics?

Plate boundaries

Mid-Atlantic Ocean Ridge South America Africa

Divergent oceanic/oceanic

Oceanic/ continental convergent Andes mountains

Oceanic/oceanic convergent

convergent continental/continental

transform 810 miles long

Mid-Atlantic Ocean Ridge South America Africa