Tackley plate tectonics and convection of the solid, rocky mantle are responsible for transporting heat out of earth. The german meteorologist alfred wegener 18801930 is largely credited with establishing the fundamentals of the theory that we now call plate tectonics. Introduction to plate tectonic theory, geodesy, and vlbi. Geologists use this word to describe the forces that shape earths surface and the rock structures that form as a result.
Continental drift theory alfred wegener, 1922 plate tectonics breakup of pangea. The difference between continental drift and plate. 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. Convection current theory cct convection current theory forms the basis of sfst and pt. In the early 1900s alfred wegener proposed the continents were drifting. According to the theory, earth has a rigid outer layer, known as the lithosphere, which is typically about 100 km 60 miles thick and overlies a plastic moldable, partially molten layer called the asthenosphere. Since this time, plate tectonic theory has established itself as the fundamental framework to study surface deformation, with the remarkable.
There is an idea or theory that the large masses of land all over earth were at one time all. The plate tectonics gizmo shows a crosssection, or side view, of earth. Continental drift, sea floor spreading and plate tectonics plate tectonics is a theory developed in the late 1960s, to explain how the outer layers of the earth move and deform. The theory of plate tectonics activityworksheet 3 volcanoes 8. Theory of plate tectonics advances in technology in the 1960s led to the development of the theory of plate tectonics which validated but improved upon wegeners earlier theory of continental drift. The theory of plate tectonics is the conceptual model through which most dynamic processes on earth are understood. The theory of plate tectonics, like every scientific theory, resulted from centuries of observations and compilation of many scientists works. The theory of plate tectonics says the continents are moving because the plates on which the continents are on are moving slowly over the molten mantle of the earth. The idea that continents may have originally occupied different positions was not a new one box 1, but wegener was the first to present the evidence in a diligent and scientific manner. Observations that led to the development of plate tectonic theory. On a separate sheet of paper, have students draw a large circle. As ideas concerning plate tectonics have evolved since the 1970s, it has become apparent that while the theory can be applied rigorously to the oceans, the same cannot be said of the continents. The theory of plate tectonics the topic of plate tectonics is largely based on alfred wegners theory of continental drift. The earth surface has continuously been changing ever since it was formed, especially regarding the geomorphological and geological phenomena.
One pile is for those students who get 100% correct like the following two examples. Wegener died in 1930 on an expedition in greenland. A plate tectonic puzzle american museum of natural history understand the theory of continental movement and plate tectonics. Plate tectonics the earths crust is divided into plates which are moved in various directions. This plate motion causes them to collide, pull apart, or scrape against each other.
Plate tectonics, our major paradigm for how the earth works, was established in the 1960ies following decades of observational research that culminated in key discoveries such as geomagnetic. We now know that, directly or indirectly, plate tectonics influences nearly. Earths geography has changed through time and continues to change today. Toward an integrated physical and chemical theory paul j. The theory of plate tectonics key concepts what is the theory of plate tectonics. Seafloor spreading occurs at divergent plate boundaries which subsequently create midocean ridges. The theory of plate tectonics explains the relative movement of crustal plates that are juxtaposed with each other to form an interlocking pattern of plate boundaries, oceanic trenches, mountain ranges, etc. Earths lithosphere is broken into separate sections called plates. The theory of plate tectonics describes how the plates move, interact, and change the physical landscape. When the concept of seafloor spreading came along, scientists recognized that it was the mechanism to explain how continents could move around earths surface. Plate tectonics describes the distribution and motion of the plates. The plates make up earths outer shell, called the lithosphere. A middle school lesson on plate tectonics theory for grades 68.
The theory has caused a revolution in the way we think about the earth. This includes the formation, movement, collision and destruction of plates and the resulting geological events such as seismicity, volcanism, continental drift, and. You will recall from a previous chapter that there are three major layers crust, mantle, core within the earth that are. Like the scientists before us, we will now merge the ideas of continental drift and seafloor spreading into the theory of plate tectonics. Because of the strength and rigidity of oceanic plates, deformation is focused into narrow linear zones along plate. The theory of plate tectonics geology lumen learning. Wegener proposed that the continents plowed through crust of ocean basins, which would explain why the outlines of many coastlines like south america and africa look like they fit together like a puzzle. The inner core is in the centre and is the hottest part of the earth. Two scientific advances in the mid20th century resulted in information critical to acceptance of continental drift and plate tectonic theory. In the early 1960s, the emergence of the theoryof plate tectonicsstarted a revolution in the earth sciences. New oceanic crust is formed through magma rising through the gap and cooling.
Plate tectonics is the theory that earths outer shell is divided into several plates that glide over the mantle. Plate tectonics is the theory that explains the global distribution of geological phenomena. Plate tectonics map of the world, showing plates, boundaries, boundary types and more. Ret 2006, rev 2 7 introduction to plate tectonic theory, geodesy, and vlbi the plate tectonic theory is a relatively new, accepted only around 50 years ago. Plate tectonics information and facts national geographic. First, the topography of the ocean floor was mapped in great detail during and after world war ii.
Teaching plate tectonics with easytodraw illustrations is fun and effective. The concept of plate tectonics was formulated in the 1960s. Several basic principles underlie the theory of plate tectonics. You will recall from a previous chapter that there are three. Note that the pdf figures in this paper, if downloaded to the. The lithosphere is divided into moving segments that change. Poorly respected in his lifetime, wegener and his ideas about moving continents seemed destined to be lost in history as fringe science. History of plate tectonics plate tectonic theory had its beginnings in 1915 when alfred wegener proposed his theory of continental drift. As plates move, the new crust gradually moves away from the ridge.
However, after a less than a year since internet publication of the brochure, i decided to change its title to the one that better reflects its content, i. There are many different categories or disciplines that make up the science of geology. However, because he could not prove his theory, it was not accepted until the 1950s. The theory of plate tectonics grew out of earlier hypotheses and observations collected during exploration of the rocks of the ocean floor. Plate tectonicsthe unifying theory of geology geology. I make three piles when i go through the exit tickets.
Above the cross section is a birdseye view of the same location. Plate tectonics a theory founded on circular arguments. The key principle of plate tectonics is that the lithosphere exists as separate and distinct tectonic plates, which ride on the. Textbooks frequently extol plate tectonics theory without questioning. In 1967, mckenzie and parker suggested the theory of plate tectonics. The former title of this brochure was falsification of the eulerian motions of lithospheric plates. Looking at the information you compiled in your chart above, explain one way the theory of plate tectonics can relate to engineering. Plate tectonics, theory dealing with the dynamics of earths outer shell that revolutionized earth sciences by providing a uniform context for. Earths surface is made up of rigid slabs of rock, or plates, which move with respect to each other constant motion tectonic. The lithosphere is broken up into seven very large continental and oceansized plates, six or seven mediumsized. I decided to change its title to the one that better reflects its content, i. Seafloor spreading helps explain continental drift in the theory of plate tectonics.
Since the development of the theory, geologists have had to reexamine almost every aspect of. It started as a hypothesis and had to be proven with hard evidence before being completely accepted by the scientific community. The difference between continental drift and plate tectonic theory. Large pieces of the lithosphere that float on the asthenosphere are called. Continental drift, sea floor spreading and plate tectonics. Principally it refers to the movement and interaction of the earths lithosphere. The structure of the earth, plate tectonics and landforms. The following website contains a more detailed and lesson plans on plate tectonics, geodesy, and vlbi. Plate tectonics pt plate tectonics is the movement of lithospheric plates relative to each other. Plate tectonics is the unifying theory of the earth how did the theory develop. The earth is composed of layers of different composition and physical properties, principally the solid central core, the fluid peripheral core, the viscous mantle, and the solid.
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