Central to the theory of plate tectonics is the concept of internal rigidity of tectonic plates together with eulers theo rem, which allows us to model the relative motion of plates. Convection current theory cct convection current theory forms the basis of sfst and pt. Demonstrating the movement of the earths crust and how tectonic plates interact at plate boundaries the theory of plate tectonics the crust is the outer layer of the earth. Plate tectonics is a theory developed in the late 1960s, to explain how the outer. Prior to the year 1900, most scientists that studied geology believed that the present position and shape of the earths continents changed very little over time. Seafloor spreading theory sfst seafloor spreading describes the movement of. This tectonic cycle has influenced the distribution of.
Demonstrating the movement of the earths crust and how tectonic plates interact at plate boundaries the theory of plate tectonics. Finally, evidence is to be found at the plate boundaries themselves. The earth surface has continuously been changing ever since it was formed, especially regarding the geomorphological and geological phenomena. The evidence for plate tectonics is very conclusive. They move atop the underlying mantle, a really thick layer of hot flowing rock.
Plate tectonicsthe unifying theory of geology geology u. All this evidence, both from the ocean floor and from the continental margins, made it clear around 1965 that continental drift was feasible and the theory of plate tectonics, which was defined in a series of papers between 1965 and 1967, was born, with all its extraordinary explanatory and predictive power. Earths geography has changed through time and continues to change today. Evidence of plate tectonics exploring earthquakes it seems javascript is either disabled or not supported by your browser. What is the strongest piece of evidence in support of the plate tectonic theory. Evidence from fossils, glaciers, and complementary coastlines helps reveal how the plates once fit together. Plate tectonics theory is taught in science classrooms around the world, but just 50 years ago it was a hotly contested theory. Despite the evidence wegener collected, he could not provide a theory explaining how the continents moved. Oct 24, 2016 what evidence do we have for plate tectonics is part of the geobus geology in a minute series. The motion in the mantle the asthenosphere is caused by convection currents.
What evidence do we have for plate tectonics is part of the geobus geology in a minute series. This activity requires students to explore a range of datasets that help substantiate plate tectonic theory. Plate tectonics is the theory that explains how large pieces of the earths outermost layer, called tectonic plates, move and change shape. The drawing above is a cross section of the earth showing the. Plate tectonics thus provides the big picture of geology. Alfred wegener suggested continental drift theory in the 1920s. 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. Plate tectonics describes the distribution and motion of the plates. Students will research the evidence collected to support the theory of plate tectonics as we know it. What is the main evidence against the plate tectonics theory. The project requires that they find 15 distinct bodies of evidence for plate tectonics and find the scientists who are credited for each.
Evidence from fossils, glaciers, and complementary coastlines helps reveal how plates once fit together. Plate tectonics is the unifying theory of geology and revolutionized. Start studying plate tectonics theory learn vocabulary, terms, and more with flashcards, games, and other study tools. The evidence that rocks closer to mid ocean ridges are younger than rocks farther away supports the theory of. Earths surface layer, 50 to 100 km 30 to 60 miles thick, is rigid and is composed of a set of large and small plates. The theory of plate tectonics grew out of earlier hypotheses and observations collected during exploration of the rocks of the ocean floor. Describe the historical development of evidence that supports plate tectonic theory.
New plate material is generated at ocean ridges, or constructive plate boundaries. The evidence against plate tectonic theory is due to the mechanics of plate movement. If it is to be understood that the earths crust is broken and divided into plates and that these plates are in constant movement and contact, then evidence would surely be found at the plate boundaries. Plate tectonic theory arose out of the hypothesis of continental drift. Theory of continental drift proposed by alfred wegener in 1912, but not widely accepted until seafloor spreading was discovered in 1960. We now know that, directly or indirectly, plate tectonics influences nearly. Below is a sample breakdown of the plate tectonics chapter into a 5day school week. The first comprehensive theory of continental drift was suggested by the german meteorologist alfred wegener in 1912. Completed timelines can be done in any format ranging fro.
Following the plate tectonic theory, the continents on the plates are still moving today, albeit very slowly. Plate tectonics is the unifying theory of the earth how did the theory develop. In essence, platetectonic theory is elegantly simple. Modern continents hold clues to their distant past. Then have them reread to identify observations that the theory of plate tectonics explains. This is because convection cell currents have not been proved conclusively to exist due to technological limitations we have never been able to get deep enough into earth to prove the theory. From wikipedia, the free encyclopedia plate tectonics from greek, tekton builder or mason describes the large.
Plate tectonic theory arose out of the hypothesis of continental drift proposed by alfred wegener in 1912 6 and expanded in his 1915 book the origin of continents and oceans. That continent eventually separated and drifted apart, forming into the seven continents we have today. 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 grew out of earlier hypotheses. Who proposed the theory and what evidence did he provide to prove his theory. Plate tectonicsthe unifying theory of geology geology. Exploring evidence of plate tectonics using geomapapp. The world map above shows the plate boundaries as well as active volcanoes.
The idea that the earths crust is made up of huge tectonic plates that are floating on an ocean of molten hot magma seemed too fantastic to be believed. Continental drift is the movement of the earths continents relative to each other, thus appearing to drift across the ocean bed. First, gather a bottle of food coloring and a large, clear glass container. Explain the process that causes the earths tectonic plates to move.
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. In 1967, mckenzie and parker suggested the theory of plate tectonics. The strikingly similar paleozoic sedimentary sequences on all southern continents and also in india are an example of evidence that supports continental drift. Continental drift, sea floor spreading and plate tectonics. Plate tectonics is the grand, unifying theory of earth sciences, combining the concepts of continental drift and seafloor spreading into one holistic theory that explains many of the major structural features of the earths surface. Together, these plates constitute the lithosphere, from the greek lithos, meaning rock. As the plates move, of course, so will the continents. 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. One of the biggest questions in geosciences today is when did plate tectonics begin on earth with a wide range of theories based on an equally diverse set of.
Continental drift and the development of plate tectonic theory. According to continental drift theory there existed one big landmass which he called pangaea which was covered by one big ocean called panthalassa. In part 1, students view flash interactives and quicktime videos which delineate the relationship between volcanoes, earthquakes and plate boundaries and discuss the ancient continent of pangaea. Read the background information and answer the following questions. List and describe the evidence for the plate tectonics theory. Continental drift theory alfred wegener, 1922 plate tectonics breakup of pangea.
The earths structure plate tectonic theory wjec gcse. We now know that, directly or indirectly, plate tectonics influences nearly all geologic processes, past and present. Plate tectonic theory both hesss discovery and wegners continental drift theory combined into what scientists now call the plate tectonic theory. The drawing above is a cross section of the earth showing the components that lie within plate tectonic theory. This video was produced by rasa juras, an undergraduate at the university of st andrews for the. This diagnostic sequence consists of glacial deposits called tillites, followed by sandstones and finally coal measures, typical of warm moist climates. Principally it refers to the movement and interaction of the earths lithosphere. Plate tectonics plate tectonics evidence supporting the hypothesis. This might appear to be convincing evidence of plate tectonics theory.
That continent eventually separated and drifted apart, forming into the seven. It may be fantastic, but that is exactly what is happening. Along the way, i disclose details of what real science is all about, details all too often absent in textbooks and classroom discussions. He put together the evidence of ancient glaciations and the. Keith challenges the very foundation of the plate tectonic model. Indeed, the notion that the entire earths surface is continually shifting has profoundly changed the way we view our world. Plate tectonics have students team read pages 158 and 159 to.
Dec 17, 2019 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. To help your child visualize the convection process that drives tectonic plate motion, try doing this simple experiment together. It is a very well supported theory, and while scientific debate continues about small parts or local effects, the overall concept is accepted as good as fact. In his seminal paper in 1993, with the thoughtprovoking title geodynamics and mantle flow. The theory of plate tectonics geology lumen learning. Pdf geological evidence for the operation of plate tectonics. A middle school lesson on plate tectonics theory for grades 68. Scientists found evidence from molten material, magnetic stripes, and drilling samples to back up wegeners theory. A plate tectonic puzzle introduction the earths crust is not a solid shell. Continental drift refers to the movement of the continents relative to each other. Since the development of the theory, geologists have had to reexamine almost every aspect of. The theory of plate tectonics combine which two other theories. What evidence did scientists find in the himalayas that support the theory of plate tectonics. The theory has caused a revolution in the way we think about the earth.
Locations of earthquakes and volcanoes show the plate boundaries and ocean floor features. L1 advanced readers plate motions point out that the arrows in figure 20 show the direction of plate motion. It is made up of thick, interconnecting pieces called tectonic plates that fit together like a puzzle. You will recall from a previous chapter that there are three. The theory of plate tectonics is based on several assumptions, the most important of which are. The earths crust and part of the upper mantle are broken into sections, called plates which move on a plasticlike layer of the mantle. The continental drift theory is the theory that once. Plate tectonics, theory dealing with the dynamics of earths outer shell that revolutionized earth sciences by providing a uniform context for. This distribution of fossils led to theories that the southern continents were once joined in a supercontinent called gondwana. Students investigate plate tectonic environments convergent, divergent, transform boundaries, topographybathymetry of continents and ocean basins, the distribution and pattern of earthquakes, the distribution of volcanoes, as well as ages of the seafloor, and more.
You will recall from a previous chapter that there are three major layers crust, mantle, core within the earth that are. Dec 16, 2019 it explains the force behind plate movements. Plate tectonics the tectonic plates of the world were mapped in the second half of the 20th century. This includes the formation, movement, collision and destruction of plates and the resulting geological events such as seismicity, volcanism, continental drift, and. According to the theory of plate tectonics, the earths lithosphere is broken into distinct plates which are. Plate tectonics is the movement of lithospheric plates relative to each other. In plate tectonics, students are introduced to the theory behind this geophysical phenomenon and investigate the evidence that supports it.
Plate tectonics is the theory that explains the global distribution of geological phenomena. According to the theory of continental drift, the world was made up of a single continent through most of geologic time. Describe the type of plate boundary that forms mountains and islands. Polar wandering similar to continental drift theory polar wandering is the relative movement of the earths crust and upper mantle with respect to the rotational poles of the earth. Plate tectonics, theory dealing with the dynamics of earths outer shell that revolutionized earth sciences by providing a uniform context for understanding mountainbuilding processes, volcanoes, and earthquakes as well as the evolution of earths surface and reconstructing its past continents and oceans. Plate tectonics evidence supporting the hypothesis. What evidence supports the theory of plate tectonics. Students will explore tectonic plate boundaries and different types of seismic waves generated by earthquakes. In the early 1960s, the emergence of the theoryof plate tectonicsstarted a revolution in the earth sciences. It started as a hypothesis and had to be proven with hard evidence before being completely accepted by the scientific community. The theory of continental drift wegener 1880 1930 alfred wegener first proposed the theory of continental drift. Prior to the year 1900, most scientists that studied geology believed that the present position and shape of. Plate tectonic theory observing convection currents convection currents are the major driving force behind the movement of tectonic plates.
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