What is the theory of continental drift?
What is the theory of continental drift?
Learn more about the theory of continental drift.
Encyclopædia Britannica, Inc.
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Encyclopædia Britannica, Inc.Learn more about the theory of continental drift.
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Encyclopædia Britannica, Inc.A discussion of some of the evidence supporting continental drift on Earth.
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© MinuteEarth (A Britannica Publishing Partner)The roles that convection currents and other forces play in the movement of Earth's tectonic plates.
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University College Cork, Ireland (A Britannica Publishing Partner)An expedition seeking hydrothermal vents in the middle of the Atlantic Ocean.
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Encyclopædia Britannica, Inc.John P. Rafferty, biological and earth science editor of Encyclopædia Britannica, discussing the connection between Earth's tectonic plates and earthquake development.
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Adapted from C.R. Scotese, The University of Texas at ArlingtonA time-lapse representation of Earth changing through geologic time, from the late Proterozoic Eon (c. 650 million years ago) to the projected period of Pangea Proxima (c. 250 million years from now).
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Encyclopædia Britannica, Inc.Marie Tharp was an American geologist and oceanographer famous for helping to create the first maps of the ocean floor.
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Encyclopædia Britannica, Inc.The shifting rock in an earthquake causes vibrations called seismic waves that travel within Earth or along its surface. The four main types of seismic waves are P waves, S waves, Love waves, and Rayleigh waves.
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Encyclopædia Britannica, Inc.
At the margins of Earth's plates, where two plates pull apart or one plate dives beneath another, magma (molten underground rock) frequently rises to the surface through volcanic vents.
Transcript
Continental drift is the idea that Earth’s continents continually undergo large-scale horizontal movements.
This theory has a long history, originating about 1800 when German naturalist Alexander von Humboldt posited that the lands bordering the Atlantic Ocean had once been joined.
He came to this theory just by looking at maps of the land itself: the eastern coast of South America looked like it could fit into the western coast of Africa.
Over the next decades, other scientists brought forth more evidence for the theory of continental drift, such as the presence of identical plant fossils in North American and European coal deposits.
In 1912 meteorologist Alfred Wegener came forward with the first truly detailed explanation of continental drift.
Wegener thought that there had actually been only one continent for most of geologic time and that the giant continent had fragmented in the late Triassic Period.
When the different landmasses began to move away from each other, they became the distinct continents we know now.
The theory of continental drift was also instrumental in developing another theory—that of plate tectonics, which explains that the movement of large sections of Earth’s crust, called tectonic plates, causes changes in Earth’s surface.
Today, plate movements are thought to shift Earth’s continents about 2 centimeters (or 0.8 inch) per year.
This theory has a long history, originating about 1800 when German naturalist Alexander von Humboldt posited that the lands bordering the Atlantic Ocean had once been joined.
He came to this theory just by looking at maps of the land itself: the eastern coast of South America looked like it could fit into the western coast of Africa.
Over the next decades, other scientists brought forth more evidence for the theory of continental drift, such as the presence of identical plant fossils in North American and European coal deposits.
In 1912 meteorologist Alfred Wegener came forward with the first truly detailed explanation of continental drift.
Wegener thought that there had actually been only one continent for most of geologic time and that the giant continent had fragmented in the late Triassic Period.
When the different landmasses began to move away from each other, they became the distinct continents we know now.
The theory of continental drift was also instrumental in developing another theory—that of plate tectonics, which explains that the movement of large sections of Earth’s crust, called tectonic plates, causes changes in Earth’s surface.
Today, plate movements are thought to shift Earth’s continents about 2 centimeters (or 0.8 inch) per year.