In plate tectonics, a divergent boundary or divergent plate boundary also known as a constructive boundary or an extensional boundary is a linear feature that exists between two tectonic plates that are moving away from each other. The tectonic plates that lie under land are called continental plates. The theory, which solidified in the 1960s, transformed the earth sciences by explaining many phenomena, including mountain building events, volcanoes, and earthquakes. This is where the plates move apart and is also called a constructive plate boundary. The plates fit together like jigsaw pieces to make up earths surface. Huttons quote predates plate tectonics theory by about oneandahalf centuries, but it seems as if he was talking about divergent and convergent. These seven continents were one big supercontinent called pangea about 200 million years ago before breaking apart. Convergent boundaries are areas where tectonics plates collide. Transform boundaries are places where two tectonic plates move horizontally past each other without increasing or decreasing in size.
Jan, 2021 there are three types of tectonic boundaries created by the movement of plates. Additionally, the movement of tectonic plates in the earths mantle have shaped and changed the land masses into what we know them to look like today. Prior to this time scientists had argued that there was no way for the plates to move around the outer surface of the earth and that the continents and ocean basins formed at the same time. In divergent boundaries plates are moving away from each other, in convergent. Divergent boundaries can occur at either thinner oceanic crust such as midocean ridges, or at. Earth and space science read and apply mega bundle. An introduction to geology johnson, affolter, inkenbrandt, and. Tectonic plate boundaries minibook with notes by the morehouse. Jul 04, 2020 the divergent plate movement in the midatlantic has led to the formation of the midatlantic ridge, a giant mountain range in the middle of the atlantic ocean. Online shopping for plate tectonics from a great selection at books store. Geol 1103 week 8 plate tectonics i based on a laboratory developed by jennifer cholnoky, angela. The convergent boundaries can make the edges of plates to buckle into mountain.
These are created when magma comes out into the space in the spreading tectonic plates. Propelled by intense heat simmering beneath the crust or the propelled by intense heat simmering beneath the crust or the mantle, earths surface is dramatically reshaping itself in an endless, slow motion movement called plate tectonics. A plate tectonics flip book around 190 million years ago, pangaea began to break up. A boundary between tectonic plates in which the plates are moving toward each other divergent boundary. Laurasia, the northern group of continents, and gondwanaland, the southern group of continents. Describe the effects of plate tectonics found at each type of boundary. All the result of convergent, divergent and transform plate boundaries. It was from the continental drift theory, convection current theory and the theory of seafloor spreading, the theory of plate tectonics was formulated. These plates undergo 3 main types of interactions which define 3 types of boundaries. Because it is so important in understanding how the world works, plate tectonics is the first topic of discussion in this textbook. Plate tectonics and boundaries science quiz quizizz.
Prior to assigning it to students, watch the video plate tectonics 5. Its outer shell is made up of huge slabs of moving rock, called tectonic plates. As students learn about the layers of the earth, theyll be able to understand how things like volcanoes are formed and have a. Plate tectonics and its types 550 words essay example. He divergent plate movement is the movement that is generated between two tectonic plates when the separation between them occurs, with lava spilling out from between them. Movement of the plates over earths surface is termed plate tectonics. In 1967, mckenzie and parker suggested the theory of plate tectonics. Chapter 1 focuses on plate tectonics, looking at the earths layers, earths evolution, and plate movement. The various color lines represent different types of boundaries between tectonic plates. Aug 11, 2020 the wilson cycle provides a broad overview of the tectonic plate movement. There are 3 types of tectonic plate movement divergent, convergent, and transform. All seven continents are where they are today due to the movement of plate tectonics.
As the plates move, they may converge, or come together. Along these boundaries, earthquakes are common and magma molten rock. The crust and upper mantle form the lithosphere, which is divided into the earths tectonic plates. Instead, two tectonic plates grind past each other in a horizontal direction. The great rift valley in africa is an example of this. Principle of plate tectonics as depicted in the book plate tectonics, by kent c. Earths surface appears to be still, but it is actually constantly on the move. Many earth processes make more sense when viewed through the lens of plate tectonics. The red sea was formed where the african and arabian plates pulled apart. Divergent boundaries are areas on the earths surface where two plates are moving apart. Geol 1103 week 8 plate tectonics i based on a laboratory developed by jennifer cholnoky, angela daneshmand, beth halfkenny, and keryn ross part 1 map observationsdynamic planet map. The movement of tectonic plates is most evident at the boundaries between the plates. The scientific theory that the earths crust is made up of plates that slowly shift position convergent boundary. In line with other previous and contemporaneous proposals, in 1912 the meteorologist alfred wegener amply described what he called continental drift, expanded in his 1915 book the origin of continents and oceans 1, and the scientific debate started that would end up fifty years later in the theory of plate tectonics.
Convergent plate boundaries occur where cooled rock becomes denser than the rocks around it and sinks back into the mantle. Plate tectonics an overview on the mechanism and effects. Motion between tectonic plates can be divergent, convergent, or transform. The earths lithosphere, which includes the crust and upper mantle, is made up of a series of pieces, or tectonic plates, that move slowly over time. A divergent boundary occurs when two tectonic plates move away from each other. This allows students to move into a collaborative learning activity as they work together to observe a model of a divergent plate boundary using poster. This is a theory put forward that says that land masses on earth move due to tectonic plate movement below. A plate tectonics flip book answers schoolworkhelper.
What are the different types of plate tectonic boundaries. Jun 18, 2018 plate tectonics is the modern version of continental drift, a theory first proposed by scientist alfred wegener in 1912. The theory of plate tectonics explains most of the features of earths surface. You will find a map in this weeks lab folder called usgs this dynamic planet. Bluepurple lines represent divergent boundaries, where plates split apart. Tectonic plates and their boundaries world in maps. Continents collide creating a supercontinent cycle. As plates made of oceanic crust pull apart, a crack in the ocean floor appears. They are thicker than the ones that lie under oceans. Tectonic plate interactions are classified into three basic types. But if these huge masses of crust are moving apart, what happens in the space left between them. Lava flows at the surface cool rapidly to become basalt, but deeper in the crust, magma cools more slowly to form gabbro. Tectonic plate boundaries divergent plate boundary.
To analyze plate movement more precisely, scientists study hotspots. The way tectonic plates interact at their margins depends on whether the crust forming the top of the plate at the point of contact is oceanic or continental. Most movement occurs along narrow zones between plates where the results of platetectonic forces are most evident. Describe how convection currents might be the cause of plate tectonics. Condie, plate tectonics is a unifying model that attempts to explain the origin of patterns of deformation in the crust, earthquake distribution, continental drift and midoceanic ridge as well as providing a. How to design and install the best solar power system for your home by paul holmes. Starting from the idea also expressed by his forerunners that the present continents once formed a single land mass which was called pangea later on that drifted. Geography form five plate tectonic theory msomi bora. Earths tectonic plates move in much the same way as you can move these books. A plate tectonics flip book answers around 190 million years ago, pangaea began to break up. Plate tectonics activity worksheet pdf kidsworksheetfun. Video shows how earths tectonic plates moved over 1 billion. It covers the 3 types of plate tectonic boundaries. In the north atlantic ocean is the midatlantic ridge that has formed where the north american and eurasian plates are separating.
Compare and contrast divergent, convergent, and transform plate boundaries. Geologists put this land movement down to something called plate tectonics. The origin of new divergent boundaries at triple junctions is sometimes thought to be associated with the. Plates move at a rate of a few centimeters a year, about the same rate fingernails grow. Plate tectonics rockin the rock cycle udl book builder. This is a 4 four page flip book that students can create that can fit into a science interactive notebook. Compare and contrast divergent, convergent, and book f 43. Plates move apart at midocean ridges where new seafloor forms. Plate tectonics plates are driven by cooling of earth convection gravity provides additional force to move plates. Satellites can measure the small distances that gps ground stations move over time. Note the elevation of the continental crust is higher than oceanic crust. The origin of new divergent boundaries at triple junctions is sometimes thought to be associated with the phenomenon known as hotspots. Gondwanaland included south america, antarctica, australia, africa, and india. Along these boundaries, earthquakes are common and magma molten rock rises from the earths mantle to the surface, solidifying to create new oceanic crust.
Plate tectonics plate tectonics is the movement of the earths crust through convection currents that occur in the mantle. Divergent plate boundaries are places where two plates are moving apart. Describe how plate tectonics processes lead to changes in earths surface features. Choose from 500 different sets of grade 7 science book plate tectonics flashcards on quizlet. Learn grade 7 science book plate tectonics with free interactive flashcards. Nowadays, it is accepted that the movements of the underlying astenospheric mantle is driving the tectonic plates. Convergent boundaries is when crust is destroyed when a plate goes under another plate. The earths lithosphere, which includes the crust and upper mantle, is made up of a series of pieces, or tectonic plates, that move slowly over time a divergent boundary occurs when two tectonic plates move away from each other. Plate tectonics information and facts national geographic. Plate motions range up to a typical 1040 mmyear midatlantic ridge. On land divergent boundaries lead to gigantic troughs.
Familiarize students with tectonic plate boundaries and plate movements through viewing plate tectonics 5. Use this map to make some preliminary observations and questions you have about what you observe on the map. This allows students to move into a collaborative learning activity as they work together to observe a model of a divergent plate. Earths geography has changed through time and continues to change today. When the concept of seafloor spreading came along, scientists recognized that it was the mechanism to explain how continents could move around earths surface. They form at boundaries where plates move together converge.
The movement of tectonic plates is so slow and gradual that you cannot see or feel them moving. Tuzo wilson in 1963, a hotspot is an area in the lithospheric plate where molten magma breaks through and creates a volcanic center, islands in the ocean and mountains on land. Inch by inch, this accounts for incredibly long distances over millions of years. Continental crustmade largely of graniteis less dense than oceanic crustmade largely of basalt. Plate tectonics allows the plates to move with relatively little buckling or breaking except at plate boundaries. The theory also takes the combination of theory of theory of isostacy, continental drift and ocean floor spreading. Plate tectonics is the movement of the earths crust through convection currents that occur in the mantle.
The key principle of plate tectonics is that the lithosphere exists as separate and distinct tectonic plates, which ride on the fluidlike viscoelastic solid asthenosphere. Utilisation of various monitoring techniques at active volcanoes and along the divergent margin has shown that spreading occurs at a rate of around 10 mmyr, and that icelands volcanoes deform in. There are a dozen large lithospheric plates smaller plates not shown. At transform boundaries, tectonic plates are not moving directly toward or directly away from each other. The movement of the plates creates three types of tectonic boundaries. This lesson plan involves exploring divergent boundaries, their features, and their locations around the world. What are tectonic plates tectonic movement dk find out. This kind of boundary results in a fault a crack or fracture in the earths crust that is associated with this movement. Condie, plate tectonics is a unifying model that attempts to explain the origin of patterns of deformation in the crust, earthquake distribution, continental drift and midoceanic ridge as well as providing a mechanism for the earth to cool. Jun 10, 2020 plate tectonics is a scientific theory that explains how major landforms are created as a result of earths subterranean movements. With the divergent movement, faults occur in the separation process, which result in holes in the ground or the appearance of a submarine mountain range.
At divergent boundaries, tectonic plates are moving away from each other. Understanding plate motions this dynamic earth, usgs. Ocean trenches are narrow, deep depressions on the ocean floor. In plate tectonics, a divergent boundary or divergent plate boundary is a linear feature that exists between two tectonic plates that are moving away from each. Divergent boundaries within continents initially produce rifts, which eventually become rift valleys. Tectonic plate facts for kids all you need to know. Beliefs in the 1940s about tectonic plate movement tectonic plate movement had been dismissed as impossible by geologists as late as the 1940s. Where diverging plates are separating fissures open on the ocean floor allowing molten rock from the mantle to flow out forming pillow basalt. Powerpoint presentation the earth, plate tectonics. Spanning a length of about ten thousand miles and height of over a mile, it is the longest mountain range on earth. Tectonic plates moving can cause tsunamis, earthquakes, and volcanoes. Tectonic plates and physical features national geographic.
At divergent boundaries, sometimes called constructive boundaries, lithospheric plates move away from. Divergent boundaries in the middle of the ocean contribute to seafloor spreading. Convergent boundaries a convergent boundary is where two tectonic plates push together. Divergent plate boundaries occur where hot magma rises to the surface, pushing the plates apart. A midocean ridge usually originates in a continental plate as a rift zone. Tectonic plates are the plates beneath us in the mantle that are constantly moving. These plate movements are caused by convection currents in the mantle. One plate will usually go underneath another and form a trench whilst lifting up the other plate, 2014. As a result, scientists depend on the global positioning system gps to verify tectonic plate motion. The movement of the tectonic plates creates three types of boundaries.
There are three main types of boundaries between plates. Plate tectonics geological features of divergent plate boundaries. Tectonic plate boundaries interactive model perkins. Divergent boundaries where new crust is generated as the plates pull away from each other. Tectonic plate movement on earth tectonic plate movement proved. The midocean ridges form at divergent plate boundaries. Movement of tectonic plates is powered by convection. The midatlantic ridge and pacific ring of fire are two examples of divergent plate boundaries. Convergent boundaries where crust is destroyed as one plate dives under another. Like the scientists before us, we will now merge the ideas of continental drift and seafloor spreading into the theory of plate tectonics.
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