Continental Drift and Alfred Wegener's Theory

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Questions and Answers

What is Pangaea?

The name of a mountain range

A type of dinosaur

A period when the Earth had no continents

A time when all the plates were together (correct)

When did Pangaea begin to break up?

About 100 million years ago

About 50 million years ago

About 400 million years ago

About 200 million years ago (correct)

What happened during the age of the dinosaurs?

Pangaea was formed

The Earth was five or six degrees cooler

New mountain ranges were formed (correct)

The Earth was covered in ice

What is the name of the video series mentioned in the text?

Great Minds Signup and view all the answers

What is the pronunciation of Alfred Wegener's last name?

Wegener Signup and view all the answers

Why is the theory of plate tectonics called a theory and not a fact?

The scientific community acknowledges that new discoveries may change it Signup and view all the answers

When did the theory of plate tectonics become widely accepted in the scientific community?

The 1960s Signup and view all the answers

What was Alfred Wagner's main evidence for his theory of continental drift?

The fit between the coastlines of Africa and South America Signup and view all the answers

What was the issue with Alfred Wagner's theory of continental drift?

He couldn't explain the mechanism behind it Signup and view all the answers

What was Alfred Wagner's profession?

Climatologist Signup and view all the answers

What is the current scientific understanding of the movement of continents?

Continents sit on top of large plates that shift around Signup and view all the answers

Who developed the hypothesis of continental drift?

Alfred Wegner Signup and view all the answers

What was one of the major problems geologists faced before the theory of plate tectonics?

They couldn't explain certain geological phenomena Signup and view all the answers

What was one of the issues with Alfred Wegner's hypothesis of continental drift?

He thought Africa and Asia were once connected Signup and view all the answers

What were the two major revolutions in geology?

The discovery of the age of the earth and the theory of continental drift Signup and view all the answers

Which layer of the Earth is the lithosphere sitting on top of?

The mantle Signup and view all the answers

What is the boundary between the mantle and the lithosphere called?

The asthenosphere Signup and view all the answers

What is the difference in thickness between oceanic and continental crust?

Oceanic crust is thinner Signup and view all the answers

What is isostasy?

The concept of floating components on the mantle Signup and view all the answers

What is the main mechanism behind plate tectonics?

Seafloor spreading and crustal plate movement Signup and view all the answers

What is the age difference between the oldest seafloor and the oldest rocks on the continents?

2 billion years Signup and view all the answers

What is the significance of fossils of shallow water marine animals found on opposite sides of continents?

They suggest that the continents were once together Signup and view all the answers

What was the main reason why the theory of continental drift was initially rejected by the scientific community?

Lack of technology Signup and view all the answers

Which layer of the Earth is about 5 miles thick?

The oceanic plate Signup and view all the answers

What is the deepest human-made hole drilled by the Russians?

4 miles down and 2 miles over Signup and view all the answers

What is the main reason why drilling to the top of the mantle is not possible?

It is too far underneath the ocean floor Signup and view all the answers

What is the thickness difference between the oceanic plate and the continental plate?

The oceanic plate is 5 miles thick and the continental plate is 20 miles thick Signup and view all the answers

Which type of plate boundary is closest to the author's location?

Transform Signup and view all the answers

What is the name of the mountain range created by the subduction process described in the text?

Andes Mountains Signup and view all the answers

What is the main reason the author begins with the divergent plate boundary?

It was the site of the discovery of the mechanism of plate tectonics. Signup and view all the answers

What is the difference between the Pacific Ocean and Juan de Fuca plates?

They are moving towards each other. Signup and view all the answers

What is the size of Antarctica compared to Australia?

Antarctica is smaller than Australia Signup and view all the answers

What is the name of the plate boundary where the Nazca Plate is moving under the South American Plate?

Subduction zone Signup and view all the answers

Which plate is NOT mentioned as being important in the text?

Eurasian Plate Signup and view all the answers

What is the reason for the distortion in the Mercator projection near the poles?

The Mercator projection is designed to show distortion near the poles Signup and view all the answers

What is the primary mechanism driving plate tectonics?

Convection in the mantle Signup and view all the answers

What causes hot air to rise?

It expands and becomes less dense than the air around it Signup and view all the answers

What is the primary process that creates new oceanic crust?

Convection in the mantle Signup and view all the answers

How long does it take for magma to complete a single turn in the convection cycle?

Thousands of years Signup and view all the answers

Which method of heat transfer is responsible for plate movement?

Convection Signup and view all the answers

What is the main reason why divergent boundaries are mostly found under the ocean?

Oceanic crust floats lower in the mantle than continental crust Signup and view all the answers

What is the process responsible for creating new seafloor at divergent boundaries?

Mantle upwelling Signup and view all the answers

What is the result of the mantle material upwelling at divergent boundaries?

Creation of new seafloor and a giant mountain range Signup and view all the answers

Which process is happening at the same speed to keep the Earth's size constant?

Formation of new crusts and destruction of old crusts Signup and view all the answers

What is the main mechanism behind the formation of oceanic ridges?

Plates pulling apart and material filling in the gap Signup and view all the answers

What is the average depth of the ocean above the mid-Atlantic ridge?

2-2.25 miles Signup and view all the answers

What was the initial misconception about the mechanism behind plate tectonics?

The mantle material was pushing up and causing volcanoes Signup and view all the answers

What is the geothermal gradient and how does it affect drilling deeper into the Earth's crust?

The geothermal gradient is the increase in temperature with depth in the Earth's crust, and drilling deeper becomes impossible due to the extreme heat. Signup and view all the answers

What is the source of heat for the Earth, and how does it move through the Earth's interior?

The source of heat for the Earth is the interior core, and it moves through the Earth's interior via convection currents. Signup and view all the answers

What is the name of the standard map projection used in the video, and what is its main limitation?

The standard map projection is called the Mercator projection, and its main limitation is that it distorts the size and shape of land masses near the poles. Signup and view all the answers

What is the main reason why we cannot drill deeper than approximately 10 kilometers into the Earth's crust?

The drill melts due to the extreme heat caused by the geothermal gradient. Signup and view all the answers

Study Notes

The History and Evidence of Continental Drift and Plate Tectonics

Wagner's evidence and sensitive instruments can track plate motion and predict future movement.
Baja Mexico will continue to move northward and take Los Angeles and Santa Barbara with it.
Models are used to predict plate movement and are very accurate.
The continental shelf fits almost perfectly together, providing evidence of past plate movement.
Matching rock types and their ages prove that continents were once together.
Fossils of shallow water marine animals found on opposite sides of continents suggest they were once together.
Glacial deposits in different continents line up to suggest they were once together.
The mechanism of continental drift was the main reason why it was initially rejected by the scientific community.
The theory of plate tectonics is now widely accepted and is based on seafloor spreading and crustal plate movement.
Seafloor mapping and earthquake studies helped to support the theory of plate tectonics.
The oldest seafloor on the planet is only 200 million years old, while the oldest rocks on the continents are about 4 billion years old.
Plate tectonics is a continually evolving field of study with ongoing research and discoveries.

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"Test your knowledge on the theory of continental drift and Alfred Wegener's evidence for it. Discover the misconceptions and the true science behind this groundbreaking theory." Keywords: continental drift, Alfred Wegener, evidence, theory, misconceptions, science.