Video: Planet Earth, The Living Machine. What is the Theory of Plate Tectonics? “It is a theory that describes the formation, movements, and interactions of earth’s plates.”. Video: Planet Earth, The Living Machine. How can the Grand Canyon reveal the history of the Earth?
What is the Theory of Plate Tectonics?
“It is a theory that describes the formation, movements, and interactions of earth’s plates.”
How can the Grand Canyon reveal the history of the Earth?
It’s rock layers show changes in time.
The oldest rocks are on the bottom and the youngest rocks are on the top.
Who was James Hutton? What was his big discovery?
The Earth is very old and the Earth is constantly changing.
James Hutton: The “Father of Geology”
Who was Alfred Wegener? What was his big idea?
Alfred Wegener was a meteorologist (person who studies weather.) He proposed the idea of continental drift.
Why was Alfred Wegener’s proclamation known as a hypothesis and not a theory?
Alfred Wegener did not have the experimental data to back up his findings.
What was Pangaea? How many millions of years ago did it start to exist and when did it start to break apart?
Pangaea means “all lands” connected together. It was a major landmass that started to break apart about 200 million years ago.
What did scientists discover in the middle of the Atlantic Ocean?
They discovered the mid-ocean ridge, a volcanic mountain chain.
What is seafloor spreading?
Seafloor spreading is when the ocean floor spreads apart (diverges) at a mid-ocean ridge.
How can rock samples record the magnetic field of the earth?
The magnetism (North or South orientation) of the planet is recorded in a rock when the lava hardens. It gives us insight into the past magnetic orientation of the Earth at different times.
What did Vine and Matthews discover on the Sea Floor at the Mid-Atlantic Ridge?
They discovered that there are alternating patterns of north and south the farther you get away from the Ridge. They also found that rocks get older as you go away from the Ridge.
How does the age of rock change the farther you go away from the Mid-Atlantic Ridge?
Rocks get older as you go away from the Mid-Atlantic Ridge.
What are 3 ways in which the Earth’s plates interact?
Plates can move towards each other (converge). Plates can move away from each other (diverge). Plates can slide past each other (transform).
What is subduction and what are the results of subduction?
Subduction is when one plate dives under another plate. The results of subduction are volcanoes and earthquakes.
How were the Himalaya mountains formed and what type of plate boundary were they formed upon?
The Himalayas were formed when the Indian Plate crashed into the Eurasian Plate. This is a convergent collision boundary.
What kind of plate boundary is the San Andreas Fault? In how many years will the San Francisco Giants and the Los Angeles Dodgers be cross-town rivals as a result of motion along this fault?
The San Andreas Fault is a transform (strike-slip) type of fault. It will take around 15 million years for the two baseball teams to become cross-town rivals.
What is thought to be the main driving force for plate tectonics in the asthenosphere and the lower mantle of the Earth?
The most accepted idea is mantle convection. Other ideas are ridge push and slab pull. Mantle Convection Animation #2
How were the Hawaiian Islands formed in the middle of the Pacific Plate?
The Hawaiian Islands were formed by a hot spot. This is when the Pacific Plate moves Northwest over the hot spot.
What happened in New Madrid, Missouri in 1812? How does this event give evidence of plate tectonics thousands of miles from the nearest plate boundary?
There was a very large earthquake. Originally, the plates were pulling apart here, forming the fault zone. Compressional forces now make this one of the most dangerous fault zones.
How do fossils and the finding of exotic terranes in the Marin Headlands near San Francisco support the theory of Micro-Plate Tectonics?
Fossils of animals and plants can be found many miles from their original place of origin. This means that they must have been carried along with the plates. We call these lands Exotic Terranes.
How did the shapes of continents shown by Christopher Scotese give rise to Alfred Wegener’s continental drift hypothesis? Explain.
Some of the continents are like puzzle pieces. They would fit together if you joined them.
How does the movement of continents influence the migration patterns of sea turtles to the Ascension Islands in the middle of the Atlantic Ocean? How is this evidence for natural selection within sea turtle species?
Sea turtles have to swim farther and farther out into the Atlantic Ocean to reach their breeding grounds on the Ascension Islands. Only the individuals strong enough to make the swim will evade jaguar predators and pass their traits off to offspring.