Admin Table of Contents
- 1 What is the force that drives plate movement?
- 2 What is the subducting plate forced into?
- 3 What force is cited as the driving force that moves the oceanic plates?
- 4 What happens to the subducted plate?
- 5 How do you tell which is the subducting plate along a subduction boundary?
- 6 In which process does the weight of a subducting plate help pull it into a subduction zone?
- 7 What type of deformation occurs at the subduction zone?
- 8 Why does the upper plate extend at subduction zones?
What is the force that drives plate movement?
The motion of tectonic plates is driven by convection in the mantle. In simple terms, convection is the idea that dense, cold things sink, and buoyant, warm things rise. In the earth the cold sinking things are slabs (subducting plates) and the warm things are plumes, or just rising material from deeper in the mantle.
What is the subducting plate forced into?
magma
This is the subduction zone. When the other plate is forced down the process is called subduction. The plate enters into the magma and eventually it is completely melted. That is how the surface of the earth makes way for the crust created over time at other plate boundaries.
What is the name of the subducting plate?
The oceanic Pacific Plate subducts under the oceanic Philippine Sea Plate forming the Mariana Trench. The oceanic Philippine Sea Plate is subducting under the Philippine Mobile Belt forming the Philippine Trench and the East Luzon Trench.
What is the movement of subduction plate?
Beyond the trench is the forearc portion of the overriding plate. Depending on sedimentation rates, the forearc may include an accretionary wedge of sediments scraped off the subducting slab and accreted to the overriding plate. However, not all arc-trench complexes have an accretionary wedge.
What force is cited as the driving force that moves the oceanic plates?
gravity
The gravity-controlled sinking of a cold, denser oceanic slab into the subduction zone, dragging the rest of the plate along with it, is considered to be the driving force of plate tectonics.
What happens to the subducted plate?
Where two tectonic plates meet at a subduction zone, one bends and slides underneath the other, curving down into the mantle. (The mantle is the hotter layer under the crust.) At a subduction zone, the oceanic crust usually sinks into the mantle beneath lighter continental crust.
What happens in the subduction zone?
Subduction zones are plate tectonic boundaries where two plates converge, and one plate is thrust beneath the other. This process results in geohazards, such as earthquakes and volcanoes. Earthquakes are caused by movement over an area of the plate interface called the seismogenic zone.
What is subduction in science?
When tectonic plates converge, one plate slides beneath the other plate, or subducts, descending into the Earth’s mantle at rates of 2-8 centimeters (1–3 inches) per year.
How do you tell which is the subducting plate along a subduction boundary?
When an oceanic lithosphere meets a continental lithosphere in a subduction zone, the oceanic plate always goes under the continental plate. This is the rule because the rock making up an oceanic lithosphere is denser than in a continental lithosphere.
In which process does the weight of a subducting plate help pull it into a subduction zone?
slab pull
The weight of a subducting plate helps pull the trailing lithosphere into the subduction zone in a process called slab pull.
What happens to the slab when plates are being subducted?
Where very old seafloor is being subducted, the slab falls almost straight down, and where younger plates are being subducted, the slab descends at a shallow angle. Subduction, in the form of gravitational “slab pull,” is thought to be the largest force driving plate tectonics.
What is the largest force driving plate tectonics?
Subduction, in the form of gravitational “slab pull,” is thought to be the largest force driving plate tectonics. At a certain depth, the high pressure turns the basalt in the slab to a denser rock, eclogite (that is, a feldspar-pyroxene mixture becomes garnet-pyroxene).
What type of deformation occurs at the subduction zone?
Earthquakes are common along the subduction zone, and fluids released by the subducting plate trigger volcanism in the overriding plate. If the subducting plate sinks at a shallow angle, the overriding plate develops a belt of deformation characterized by crustal thickening, mountain building, and metamorphism.
Why does the upper plate extend at subduction zones?
This explains why there are often zones of stretching, or crustal extension, in the upper plate at subduction zones. Where the subducting slab bends downward, a deep-sea trench forms. The deepest of these is the Mariana Trench, at over 36,000 feet below sea level.