EARTH AND SPACE SCIENCE
... cooler material sinks back toward the core. The resulting convection currents can be thousands of kilometers across but flow at rates of only a few centimeters per year. ...
... cooler material sinks back toward the core. The resulting convection currents can be thousands of kilometers across but flow at rates of only a few centimeters per year. ...
Chapter 8 Volcanoes Section 1, Why Volcanoes Form
... that the area is called the Ring of Fire. • At tectonic plate boundaries, several processes cause rock to melt. • Molten rock is called ...
... that the area is called the Ring of Fire. • At tectonic plate boundaries, several processes cause rock to melt. • Molten rock is called ...
Unit 3 Lesson 1 Geological History
... representing the mid-oceanic ridge are mirror images of one another. The shaded stripes also represent older and older rock as they move away from the mid-oceanic ridge. Geologists have determined that rocks found in different parts of the planet with similar ages have the same magnetic characterist ...
... representing the mid-oceanic ridge are mirror images of one another. The shaded stripes also represent older and older rock as they move away from the mid-oceanic ridge. Geologists have determined that rocks found in different parts of the planet with similar ages have the same magnetic characterist ...
Plate Boundary: Oceanic-Continental
... against each other or pull away which causes much pressure and results to the different types of faults; or in the case of volcanoes, results in spreading or sinking. When the plates spread or sink it causes melting, that creates molten rock. When this molten rock is beneath earth’s surface it is ca ...
... against each other or pull away which causes much pressure and results to the different types of faults; or in the case of volcanoes, results in spreading or sinking. When the plates spread or sink it causes melting, that creates molten rock. When this molten rock is beneath earth’s surface it is ca ...
The Edible Earth: Plate Movements
... variety of interactions at the plate boundaries. The boundaries of these crustal plates collide, diverge, or slip past each other. Some plate boundaries appear to be inactive. When plates collide they can buckle against each other, or one plate might slip beneath the other. If plates diverge, or pul ...
... variety of interactions at the plate boundaries. The boundaries of these crustal plates collide, diverge, or slip past each other. Some plate boundaries appear to be inactive. When plates collide they can buckle against each other, or one plate might slip beneath the other. If plates diverge, or pul ...
Chapter 6 Section 2
... The denser oceanic lithosphere will sink beneath the less-dense continental crust, in a process called subduction. ...
... The denser oceanic lithosphere will sink beneath the less-dense continental crust, in a process called subduction. ...
Manea et al. 2004 - University of Alberta
... Thus, the convergence rate of 5.5 cm yr−1 between the Cocos and North American plates is used in our models (DeMets et al. 1994). The velocities in the subducting Cocos slab beneath the volcanic arc are set at 5.5 cm yr−1 ; therefore, the interface with the mantle wedge is pre-defined. The boundary ...
... Thus, the convergence rate of 5.5 cm yr−1 between the Cocos and North American plates is used in our models (DeMets et al. 1994). The velocities in the subducting Cocos slab beneath the volcanic arc are set at 5.5 cm yr−1 ; therefore, the interface with the mantle wedge is pre-defined. The boundary ...
Plate Tectonics - British Geological Survey
... Nazca, Antarctic, Pacific, Juan De Fuca and Indian-Australian. ...
... Nazca, Antarctic, Pacific, Juan De Fuca and Indian-Australian. ...
Do you understand plate boundaries?
... When two plates move towards one another, they form a subduction zone or a continental collision. Pressure and friction build up at destructive plate boundaries. Earthquakes and volcanoes are common near destructive plate boundaries. Large fold mountain ranges are formed during collisions between tw ...
... When two plates move towards one another, they form a subduction zone or a continental collision. Pressure and friction build up at destructive plate boundaries. Earthquakes and volcanoes are common near destructive plate boundaries. Large fold mountain ranges are formed during collisions between tw ...
World Tectonic Mapping Activity
... 12. Where is magma rising to the surface and forming ocean crust? Where is the oceanic crust sinking back into the mantle? 13. Some people have referred to the process in the above question as a cycle. Why would it be considered a cycle? 14. What are the attributes of a cycle? Can you describe anoth ...
... 12. Where is magma rising to the surface and forming ocean crust? Where is the oceanic crust sinking back into the mantle? 13. Some people have referred to the process in the above question as a cycle. Why would it be considered a cycle? 14. What are the attributes of a cycle? Can you describe anoth ...
tectonic plates
... What is the Ring of Fire? A zone of active volcanoes and earthquakes that marks the Pacific Plate boundary Deep- point that goes very far down into the crust Trench- steep, narrow valley where a plate ends ...
... What is the Ring of Fire? A zone of active volcanoes and earthquakes that marks the Pacific Plate boundary Deep- point that goes very far down into the crust Trench- steep, narrow valley where a plate ends ...
Boundary Types (1) PowerPoint
... The continents are moving because of sea floor spreading. • Running down the middle of the oceans are long mountain chains with valleys in the middle called mid ocean ridges. Lava erupts from the center of the valley and pushes the ocean floor away on the other side. The Mid-Atlantic Ridge is separ ...
... The continents are moving because of sea floor spreading. • Running down the middle of the oceans are long mountain chains with valleys in the middle called mid ocean ridges. Lava erupts from the center of the valley and pushes the ocean floor away on the other side. The Mid-Atlantic Ridge is separ ...
Theory of Plate tectonics
... Divergent Plate Boundaries • Plates separate (move away from each other) • Almost always occurs between two ocean plates. • When ocean plates separate, new crust is formed through the upwelling of magma. This is called sea-floor spreading. – http://education.sdsc.edu/optiputer/flash/seafloorspread. ...
... Divergent Plate Boundaries • Plates separate (move away from each other) • Almost always occurs between two ocean plates. • When ocean plates separate, new crust is formed through the upwelling of magma. This is called sea-floor spreading. – http://education.sdsc.edu/optiputer/flash/seafloorspread. ...
492 Island Arcs
... the trench. The fore-arc region comprises the trench itself, the subduction complex (the ‘first arc’ or accretionary wedge or prism) and the fore-arc basin. The subduction complex is constructed of thrust slices of trench fill sediments and also possibly oceanic crust, which have been scraped off th ...
... the trench. The fore-arc region comprises the trench itself, the subduction complex (the ‘first arc’ or accretionary wedge or prism) and the fore-arc basin. The subduction complex is constructed of thrust slices of trench fill sediments and also possibly oceanic crust, which have been scraped off th ...
Ocean Basins - University of Washington
... e.g., Andes and Peru-Chile Trench Subduction occurs when ocean crust carried down into Mantle (e.g., b and c above) basalt and sediment heated to form volcanic magma ...
... e.g., Andes and Peru-Chile Trench Subduction occurs when ocean crust carried down into Mantle (e.g., b and c above) basalt and sediment heated to form volcanic magma ...
Ch19_PlateTectonics
... symmetrically oriented about ridges? A) Rates of plate motions on the two divergent plates are the same for both plates B) Magma is intruded into the centers of spreading ridges and then pulled apart in the middle C) Convective cells in the mantle transfer heat and move rock straight up beneath ridg ...
... symmetrically oriented about ridges? A) Rates of plate motions on the two divergent plates are the same for both plates B) Magma is intruded into the centers of spreading ridges and then pulled apart in the middle C) Convective cells in the mantle transfer heat and move rock straight up beneath ridg ...
Transient plume- to continuous plate
... In the frame of plate tectonics, the East African Rift system (EARS) is the largest active tectonic structure illustrating the early stage of continental plate fragmentation. The occurrence of continental flood basalts and large topographic plateaux has long been interpreted as witnessing the key ro ...
... In the frame of plate tectonics, the East African Rift system (EARS) is the largest active tectonic structure illustrating the early stage of continental plate fragmentation. The occurrence of continental flood basalts and large topographic plateaux has long been interpreted as witnessing the key ro ...
Formation of Crustal Features - Flipped Out Science with Mrs. Thomas!
... When an ocean plate subducts under a continental plate, as shown at (4) in the diagram on the previous page, compressional forces at the edge of the continental plate will also create some folding mountains. But magma from the subducting ocean plate also can build mountains parallel to the subductio ...
... When an ocean plate subducts under a continental plate, as shown at (4) in the diagram on the previous page, compressional forces at the edge of the continental plate will also create some folding mountains. But magma from the subducting ocean plate also can build mountains parallel to the subductio ...
Volcanoes and Igneous Activity Earth - Chapter 4 - sir
... two oceanic slabs converge, one descends beneath the other Often forms volcanoes on the ocean floor If the volcanoes emerge as islands, a volcanic island arc is formed - Japan, the Aleutian islands, and the Tonga islands are examples ...
... two oceanic slabs converge, one descends beneath the other Often forms volcanoes on the ocean floor If the volcanoes emerge as islands, a volcanic island arc is formed - Japan, the Aleutian islands, and the Tonga islands are examples ...
Oceanic trench
The oceanic trenches are hemispheric-scale long but narrow topographic depressions of the sea floor. They are also the deepest parts of the ocean floor. Oceanic trenches are a distinctive morphological feature of convergent plate boundaries, along which lithospheric plates move towards each other at rates that vary from a few mm to over ten cm per year. A trench marks the position at which the flexed, subducting slab begins to descend beneath another lithospheric slab. Trenches are generally parallel to a volcanic island arc, and about 200 km (120 mi) from a volcanic arc. Oceanic trenches typically extend 3 to 4 km (1.9 to 2.5 mi) below the level of the surrounding oceanic floor. The greatest ocean depth to be sounded is in the Challenger Deep of the Mariana Trench, at a depth of 11,034 m (36,201 ft) below sea level. Oceanic lithosphere moves into trenches at a global rate of about 3 km2/yr.