Podcast
Questions and Answers
Who proposed the continental drift theory?
Who proposed the continental drift theory?
When was the idea of Pangaea formally accepted by the scientific community?
When was the idea of Pangaea formally accepted by the scientific community?
What is the main assertion of the continental drift theory?
What is the main assertion of the continental drift theory?
What evidence did Alfred Wegener use to support the continental drift theory?
What evidence did Alfred Wegener use to support the continental drift theory?
Signup and view all the answers
Which theory embodies the modern concepts of how the continents and the oceans evolved?
Which theory embodies the modern concepts of how the continents and the oceans evolved?
Signup and view all the answers
What did paleomagnetic studies provide evidence for?
What did paleomagnetic studies provide evidence for?
Signup and view all the answers
Why did Wegener's theory not gain acceptance initially?
Why did Wegener's theory not gain acceptance initially?
Signup and view all the answers
What did the symmetric patterns of magnetic field reversals in ocean floor rocks suggest?
What did the symmetric patterns of magnetic field reversals in ocean floor rocks suggest?
Signup and view all the answers
What did the past records of climates, glaciation in Africa and coal deposits in Antarctica suggest?
What did the past records of climates, glaciation in Africa and coal deposits in Antarctica suggest?
Signup and view all the answers
What was the main conclusion drawn from the age comparison between ocean floor rocks and continental rocks?
What was the main conclusion drawn from the age comparison between ocean floor rocks and continental rocks?
Signup and view all the answers
The idea of ______ is no more than a century old, and it was only formally accepted by the scientific community around 50 years ago. Compare this with the model of the planets revolving around the Sun along elliptical orbits, which had been firmly established by the end of the 17th century. The theory of plate tectonics which embodies the modern concepts of how the continents and the oceans evolved is a fairly young theory.
The idea of ______ is no more than a century old, and it was only formally accepted by the scientific community around 50 years ago. Compare this with the model of the planets revolving around the Sun along elliptical orbits, which had been firmly established by the end of the 17th century. The theory of plate tectonics which embodies the modern concepts of how the continents and the oceans evolved is a fairly young theory.
Signup and view all the answers
The theory of ______ embodies the modern concepts of how the continents and the oceans evolved is a fairly young theory. In this module, we will be discussing how this theory, which is very important to the Earth sciences, developed from the earlier ideas of continental drift and seafloor spreading.
The theory of ______ embodies the modern concepts of how the continents and the oceans evolved is a fairly young theory. In this module, we will be discussing how this theory, which is very important to the Earth sciences, developed from the earlier ideas of continental drift and seafloor spreading.
Signup and view all the answers
Continental drift Continents, as massive and immovable as they seem to be, had been moving over great distances relative to each other. This is the main assertion of the ______ drift theory, proposed by Alfred Wegener, a German meteorologist, geophysicist and polar researcher, in several publications, such as his 1915 book, The Origin of Continents and Oceans.
Continental drift Continents, as massive and immovable as they seem to be, had been moving over great distances relative to each other. This is the main assertion of the ______ drift theory, proposed by Alfred Wegener, a German meteorologist, geophysicist and polar researcher, in several publications, such as his 1915 book, The Origin of Continents and Oceans.
Signup and view all the answers
He based his theory on the following ______: South American and African coastlines seem to fit like jigsaw puzzle pieces, matching mountain ranges across the Atlantic Ocean are of similar age and structure.
He based his theory on the following ______: South American and African coastlines seem to fit like jigsaw puzzle pieces, matching mountain ranges across the Atlantic Ocean are of similar age and structure.
Signup and view all the answers
Existing ______. Do NOT ask these: When was the idea of Pangaea formally accepted by the scientific community?
Existing ______. Do NOT ask these: When was the idea of Pangaea formally accepted by the scientific community?
Signup and view all the answers
Fossils of certain species of terrestrial plants and animals found in separate continents. past records of climates -- glaciation (cold climate) in Africa (tropical climate) coal deposits in Antarctica -- which are not consistent with the present location of the continents. The first three arguments suggest that the present-day continents, separated by oceans, were once connected to each other. The last argument suggests a change in position of the continents relative to the polar region. As part of his theory, Wegener proposed that the present-day continents were, in the past, all merged into a supercontinent called ______
Fossils of certain species of terrestrial plants and animals found in separate continents. past records of climates -- glaciation (cold climate) in Africa (tropical climate) coal deposits in Antarctica -- which are not consistent with the present location of the continents. The first three arguments suggest that the present-day continents, separated by oceans, were once connected to each other. The last argument suggests a change in position of the continents relative to the polar region. As part of his theory, Wegener proposed that the present-day continents were, in the past, all merged into a supercontinent called ______
Signup and view all the answers
His theory, however, did not gain acceptance from the mainstream scientific community, because he was not able to provide a sound explanation as to how the continents were able to move about. As a result, the theory was downplayed, and considered unscientific up until the ______
His theory, however, did not gain acceptance from the mainstream scientific community, because he was not able to provide a sound explanation as to how the continents were able to move about. As a result, the theory was downplayed, and considered unscientific up until the ______
Signup and view all the answers
But starting in the 1950’s, paleomagnetic studies (study of magnetic fields as recorded by magnetic minerals during the formation of rocks) provided more convincing evidence for the relative movement of ______
But starting in the 1950’s, paleomagnetic studies (study of magnetic fields as recorded by magnetic minerals during the formation of rocks) provided more convincing evidence for the relative movement of ______
Signup and view all the answers
The assumption is that magnetic minerals in rocks formed at the same time but in different continents will point to the same location of the magnetic north pole (because there is only one magnetic field for the Earth). However, when scientists tried to plot the ancient magnetic poles based on same-aged rocks from different continents, the magnetic poles did not ______
The assumption is that magnetic minerals in rocks formed at the same time but in different continents will point to the same location of the magnetic north pole (because there is only one magnetic field for the Earth). However, when scientists tried to plot the ancient magnetic poles based on same-aged rocks from different continents, the magnetic poles did not ______
Signup and view all the answers
The above discoveries provided evidence for a hypothesis that the ocean floor is being rifted or split apart along the MORs by the convection of hot material ______
The above discoveries provided evidence for a hypothesis that the ocean floor is being rifted or split apart along the MORs by the convection of hot material ______
Signup and view all the answers
