![]() ![]() Plate Tectonics explains what happens as the North American and Eurasian Plates pull away from each other new crust is formed from erupted magma along either side of the ridge. The edge of the plates are uplifted, crumpled, and folded. The divergent boundary, called the Mid-Atlantic Ridge, that runs through the center of Iceland occurs because two plates, the North American Plate and the Eurasian Plate, are pulling away from each other. ![]() They move the plates above., Mid-ocean ridge - A seafloor mountain range composed of cooled lava and underwater volcanoes., Oceanic Plate - A thin, dense crust found under oceans., Continental Plate - A thick, less dense crust that makes up the continents., Subduction zone - A region where one tectonic plate moves under the other and sinks into the mantle., Seismic wave - A wave of energy produced by an earthquake., Fault - A break/crack in the earth’s surface., Fold mountains - A series of mountains that have been created due to two or more of Earth's tectonic plates being pushed together. ![]() Large earthquakes can occur here., Convection currents - Movement within the mantle caused by the heat of the core. Letters in ovals are codes for NPS sites at modern and ancient convergent plate boundaries. Plates hit into each other and fold upwards., Conservative - This is a passive plate boundary where plates slide past each other. The landscapes of many National Park Service sites show convergent plate boundary processes that result in a variety of mountain ranges and complex geological structures characteristic of subduction zones, accreted terranes and collisional mountain ranges. One plate sinks beneath the other and is destroyed, Collision - This is a convergent plate boundary where plates move towards each other. This allows magma to reach the surface, cool, and form new crust, Destructive - This is a convergent plate boundary where plates move towards each other. Most destructive boundaries are associated with a belt of active volcanoes that, in the case of intra-oceanic boundaries, form chains of islands known as island arcs.Constructive - This is a divergent plate boundary where plates are moving apart. Earthquakes can occur as deep as 600-700 km A subduction zone consists of material scraped off the ocean floor near the coast (accretionary wedge) and a chain of volcanoes farther inland (volcanic arc). They are continuous for many hundreds of kilometres, occurring both adjacent to continents and wholly within oceans Ī belt of earthquakes that are shallow-centred closest to the trench and deeper further away. Convergent Plate Boundary Development Subduction Where tectonic plates converge, the one with thin oceanic crust subducts beneath the one capped by thick continental crust. It is a constructive plate boundary of the four boundaries. This leads to the creation of more rivers or huge water bodies. These different types of plate boundaries are stated below: Divergent Boundaries: These types of tectonic plate boundaries are formed when two tectonic plates are moving away from one another. The sea floor slopes into the trenches from both the landward and oceanward sides. Depending on the movement of the tectonic plates relative to each other, there are four different types of plate boundaries. Convergent boundaries, where two plates are moving toward each other, are of three types, depending on the type of crust present on either side of the boundary. Ocean trenches, generally 5-8 km deep, but sometimes up to 11 km deep. ![]() In addition to the disappearance of old lithosphere, destructive boundaries associated with ocean-ocean subduction and ocean-continent subduction are also characterised by: These can be thought of as representing three stages in the evolution of destructive boundaries. Those where an oceanic plate converges with a continental plate (ocean-continent subduction)Ĭollisions between two continental plates (continent-continent destructive boundaries). Deep trenches appear at these boundaries, caused by the oceanic plate bending. Those involving the convergence of two oceanic plates (ocean-ocean subduction) The boundary where the two plates meet is called a convergent boundary. Consequently, there are three possible types of destructive plate boundary: Secondly, whereas true constructive boundaries occur almost invariably in oceanic lithosphere, destructive boundaries also affect continental lithosphere - they can occur entirely within continental lithosphere. Firstly, and in contrast to constructive plate boundaries, destructive plate boundaries are asymmetrical with regard to plate speeds, age and large-scale structures. This situation provides a more varied range of tectonic settings than do constructive plate boundaries. Destructive plate boundaries are regions where two lithospheric plates converge. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |