Is continental or oceanic plates heavier?
Because of their heavy ferromagnesian elements, oceanic plates are much denser than continental plates. The average density of ocean plates is approximately 200 pounds per cubic foot, while continental crust ranges between about 162 and and 172 pounds per cubic foot.
What are 3 differences between oceanic and continental crust?
It is the solid rock layer upon which we live. It is either continental or oceanic. Continental crust is typically 30-50 km thick, whilst oceanic crust is only 5-10 km thick. Oceanic crust is denser, can be subducted and is constantly being destroyed and replaced at plate boundaries.
What are the similarities and differences between oceanic and continental crust?
Layers that are less dense, such as the crust, float on layers that are denser, such as the mantle. Both oceanic crust and continental crust are less dense than the mantle, but oceanic crust is denser than continental crust. This is partly why the continents are at a higher elevation than the ocean floor.
What is the difference between oceanic and continental lithosphere?
Oceanic lithosphere is typically about 50-100 km thick (but beneath the mid-ocean ridges is no thicker than the crust). The continental lithosphere is thicker (about 150 km). It consists of about 50 km of crust and 100 km or more of the uppermost mantle.
Which part of lithosphere is the thinnest?
The most well-known feature associated with Earth’s lithosphere is tectonic activity. Click below to visit our MapMaker Interactive layer displaying the lithosphere’s tectonic plates. The lithosphere is thinnest at mid-ocean ridges, where tectonic plates are tearing apart from each other.
Why is the continental crust so old?
It is due to the process of subduction; oceanic crust tends to get colder and denser with age as it spreads off the mid-ocean ridges. As the continental crust is lighter than the oceanic crust, the continental crust cannot subduct. We therefore still have some very old continental rocks at the surface of the Earth.
What keeps the plate edges from sliding smoothly past each other?
Friction between the plates keeps them from sliding. When the frictional strain is overcome, the ground suddenly snaps along faults and fractures releasing energy as earthquakes.
What happen if two crust collide?
At convergent boundaries, where plates push together, crust is either folded or destroyed. When two plates with continental crust collide, they will crumple and fold the rock between them. A plate with older, denser oceanic crust will sink beneath another plate. The crust melts in the asthenosphere and is destroyed.
What happens when two crusts collide?
If two tectonic plates collide, they form a convergent plate boundary. Usually, one of the converging plates will move beneath the other, a process known as subduction. The new magma (molten rock) rises and may erupt violently to form volcanoes, often building arcs of islands along the convergent boundary.
What happens when two oceanic collide?
When two oceanic plates collide one oceanic plate is eventually subducted under the other. This andesitic magma is formed from the partial melting of the asthenosphere just above the subduction zone. This partial melting of the subducting plate is due to the loss of water as it descends into the mantle.