Six of the majors are named for the continents embedded within them, such as the north american, african, and. The crust is broken up into giant tectonic plates that ride atop the magma, hot meltedrock. Plate tectonics is a theory developed in the late 1960s, to explain how the outer layers of the. Continental drift, sea floor spreading and plate tectonics. Tectonic plates and continental drift animation youtube. Tectonic plate lithospheric plate is a massive, irregularly shaped slab of solid rock, generally composed of continental and oceanic lithosphere. This series offers a detailed, informative and lively discussion on four of the key areas of physical geography. It explains that the continents drifted apart because of the constant interaction between the earths tectonic plates and the heat of the earths core. The speculation that continents might have drifted was first put forward by abraham ortelius in 1596. The study of the origin and arrangement of earth surface including mountain belts, continents, and earthquake belts. Plate tectonics, the study of the arrangements of continents and oceans on the surface of the. The movement of the plates creates three types of tectonic boundaries. The structure of the earth, plate tectonics and landforms. Plate tectonics is the theory that explains the structure, composition and internal workings of the earth on a worldwide scale, while continental drift refers to the theory that the continents all used to be connected in one megacontinent which scientists dub pangaea.
Ocean, and the indian block drifted across the equator to merge with asia. Movement of the plates over earths surface is termed plate tectonics. Plate tectonicscontinental drift and mountain building. Chapter 1 from continental drift to plate tectonics naomi oreskes since the l6th century, cartographers have noticed the jigsawpuzzle fit of the continental edges. Continental drift and plate tectonics kaiserscience. At convergent margins, continents grow as plates are consumed. A new island can be created above the hot spot in the same place as the previous island and in this way a.
Difference between continental drift and plate tectonics. Oceanic crust is mainly composed of silicon and magnesium, hence called sima. Continental drift theory alfred wegener, 1922 plate tectonics breakup of pangea. Students will examine plate boundaries, continents, and oceans on a globe. Speed of the continental plates from zhen shao huang. Plate tectonics, the study of the arrangements of continents and oceans. In the early 20th century, wegener published a paper explaining. The concept of plate tectonics is that the lithosphere, which is the higher layers of the earths surface, is separated into a number of plates that float independently over the mantle and along the boundaries that initiate the development of new crust, the building of mountains, and the seismic movement that triggers earthquakes geosystems 340. The theory encompasses the older concepts of continental drift, developed.
Pdf a historical account of how continental drift and plate tectonics. Convection current theory cct convection current theory forms the basis of sfst and pt. Wegeners continental drift meets wilsons plate tectonics. The lithosphere is broken up into seven very large continental and oceansized plates, six or seven mediumsized regional plates, and several small ones. Continental drift is the theory that the earths continents have moved over geologic time relative to each other, thus appearing to have drifted across the ocean bed. How does plate tectonics compare to the continental drift. Alfred wegener was the first to offer a comprehensive theory about continental drift but failed to provide a feasible explanation about how continents actually. Plate tectonics the tectonic plates of the world were mapped in the second half of the 20th century.
Continental drift and plate tectonics university of iceland. The widespread distribution of certain plant groups correlates rather nicely with plate tectonics. Plate tectonics, 540ma modern world scotese animation 022116b duration. This plate motion causes them to collide, pull apart, or scrape against each other. For example, there are three families of cycads, the cycadaceae, stangeriaceae and zamiaceae, which include a total of 185 species in 11 genera. The concept was independently developed by german geologist alfred wegener in 1912. According to the theory of continental drift, the world was made up of a single continent through most of geologic time. Video showing how convection cells inside the earth move tectonic plates on the earths surface. Continental drift pangea final pangea plate tectonics english version duration.
Plate tectonics it was from the continental drift theory, convection current theory and the theory of seafloor spreading, the theory of plate tectonics was formulated. From continental drift to plate tectonics 7 and therefore they could not sink to become ocean basins. This is a united learning video on plate tectonics and continental drift. Plate tectonics the earths crust is divided into plates which are moved in various directions. Plate tectonics information and facts national geographic. In the early 1900s alfred wegener, a german earth scientist proposed the idea that the continents as we believe are not stationary, but as a matter of fact, have been drifting about on the earths surface over millions of years of geologic time. The continental drift theory states that the continents were once parts of a supercontinent called pangea. What is the difference between continental drift and plate. Where plates come together, or converge, we see some dramatic manifestations of plate tectonics. Plate tectonics from the university of tennessee knoxville. They move at a rate of one to two inches three to five centimeters per year.
One of the most important contributions to the development of plate tectonic theory was alfred wegeners 1915 publication of the origin of continents and oceans which outlined his theory of continental drift. Convergent boundary between continental and oceanic crust. There are a few handfuls of major plates and dozens of smaller, or minor, plates. However, wegeners theory of continental drift, which was published in 1915 and is regarded by many as the direct precursor of modern plate tectonics, contributed astonishingly little to the understanding of mountain building processes. Plate tectonics and continental drift infographic live. Plate tectonics theory the upper most mantle, along with overlying crust, behaves as a strong, rigid layer. The difference between continental drift and plate. Continental drift, in the context of the modern theory of plate tectonics, is explained by the movement of lithospheric plates over the asthenosphere the molten, ductile, upper portion of the earths mantle. The theory of continental drift is most associated with the scientist alfred wegener. Continental drift is horizontal movements of continents with respect to one another and to the basins in geologic time. The theory of plate tectonics and continental drift bartleby. The difference between continental drift and plate tectonic theory. Continental drift is a theory first presented by abraham ortelius abraham ortels in 1596. That continent eventually separated and drifted apart, forming into the seven continents we have today.
The contribution of hess hess measured the oceans to the deepest points to date, 10. Scientific data and observation now allows us to merge the ideas of continental drift and seafloor spreading into the theory of plate tectonics. The relationship of continental drift and plate tectonics is that the plate tectonics move and are under the ground and the continental drift is on the top of earth. Continental drift describes one of the earliest ways geologist s thought continent s moved over time. In 1967, mckenzie and parker suggested the theory of plate tectonics. Plate tectonics from the us geological service advertisement. Each book helps develop the knowledge of how specific features of the earth are formed, their causes and effects, patterns and processes, and our study and understanding of. Continental drift and plate tectonics are two theories explaining the geological evolution of the earth, specifically its crust. Having often survived cycles of merging and rifting of continents, cratons are generally found in the interiors of tectonic plates. Today, the theory of continental drift has been replaced by the science of plate tectonics. More than two dozen scientists, including women such as tanya atwater and marie tharp, did the key work that created the theory of plate tectonics as we know it explaining continental drift. The theory of plate tectonics geology lumen learning.
He discovered hundreds of flattopped mountains on the pacific floor. Describe how the ideas behind plate tectonics started with alfred wegeners hypothesis of continental drift describe the physical and chemical layers of the earth and how they affect plate movement explain how movement at the three types of plate boundaries causes earthquakes, volcanoes, and. Students will create a model of the earth that they can hold and examine. Like the scientists before us, we will now merge the ideas of continental drift and seafloor spreading into the theory of plate tectonics. These plates move relative to each other, typically at rates of 5 to 10 cm 2 to 4 inches per year, and. Continental drift was a theory that explained how continents shift position on. Questions and answers about continental drift from monash university earth sciences. Plate tectonics tennis ball globe students will examine one method for creating a twodimensional map of a spherical surface. Plate tectonics by combining the sea floor spreading theory with continental drift and information on global seismicity, the new theory of plate tectonics became a coherent theory to explain crustal movements.
Wegener supported his argument with five lines of evidence. We now know that, directly or indirectly, plate tectonics influences nearly all geologic processes, past and present. Learn plate tectonics continental drift questions with free interactive flashcards. As plate tectonics, or continental drift, slowly moves the island along with the plate. Continental drift the basic theory of plate tectonics. Choose from 500 different sets of plate tectonics continental drift questions flashcards on quizlet. Look at the diagram under the continental continental information. What happens when two continents meet headon, meet headon and neither is subducted. Contractional theory, continental drift and plate tectonics.
According to the theory of plate tectonics, the earths lithosphere is broken into distinct plates which are. Each type of interaction causes a characteristic set of earth structures or tectonic features. The plate tectonics theory is based on the continental drift theory in that it explains how the supercontinent drifted apart into several plates. How is plate tectonics and continental drift the same. The concept was independently and more fully developed by alfred wegener in 1912, but his theory was rejected by many for. They have a thick crust and deep lithospheric roots that extend as much as several hundred km into the mantle. Lithosphere is divided into plates that slide around on top of the slowly moving mesosphere tectonic plates it occurred after the breakup of pangaea, and since then the continents have drifted apart. So whats the difference between continental drift and plate tectonics. What mountain range demonstrates one of the most visible and spectacular consequences of plate tectonics. Plate tectonics and continental drift fleagle major. The lithosphere is divided into moving segments that change. Indeed, the notion that the entire earths surface is continually shifting has profoundly changed the way we. When the concept of seafloor spreading came along, scientists recognized that it was the mechanism to explain how continents could move around earths surface.
Third, and most fundamental, physicists discovered radiogenic heat, which contradicted the basic assumption. Two main types of tectonics plates are the oceanic crust and continental crust. Ever since the first global maps were drawn following the great voyages of discovery of the 15th and 16th centuries, it has been realised that the coastline geography of the continents on either side of the atlantic ocean form a pattern that can be fitted back together. The development of the theory of continental drift and plate tectonics illustrates the tortuous. Plate tectonics and continental drift fleagle major reference. Plate tectonics is the theory explaining the motion of the outer crust or the lithosphere of earth. Plates move at a rate of a few centimeters a year, about the same rate fingernails grow. Plate tectonicscontinental drift and mountain building article pdf available in bulletin of volcanology 741. Continental drift and plate tectonics f you look closely at a world map, you might notice something about the coastlines of south america and africa. Alfred wegener and the concept of continental drift.
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