What happens to the asthenosphere is lithospheric plates move at the three types of plate boundaries?
Heat within the asthenosphere creates convection currents that cause tectonic plates to move several centimeters per year relative to each other. 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.
What happens in the asthenosphere that provides the force to move lithospheric plates?
Heat from deep within Earth is thought to keep the asthenosphere malleable, lubricating the undersides of Earth’s tectonic plates and allowing them to move. Convection currents generated within the asthenosphere push magma upward through volcanic vents and spreading centres to create new crust.
What happens when lithospheric plates move?
When the plates move they collide or spread apart allowing the very hot molten material called lava to escape from the mantle. When collisions occur they produce mountains, deep underwater valleys called trenches, and volcanoes. The Earth is producing “new” crust where two plates are diverging or spreading apart.
What are the 3 types of plate boundaries and what happens at each?
Tectonic Plates and Plate Boundaries
- There are three main types of plate boundaries:
- Convergent boundaries: where two plates are colliding.
- Divergent boundaries – where two plates are moving apart.
- Transform boundaries – where plates slide passed each other.
How do plate boundaries affect humans?
Occasionally, big eruptions or earthquakes kill large numbers of people. If we choose to live near convergent plate boundaries, we can build buildings that can resist earthquakes, and we can evacuate areas around volcanoes when they threaten to erupt.
What will happen if plate tectonics stopped?
If all plate motion stopped, Earth would be a very different place. Erosion would continue to wear the mountains down, but with no tectonic activity to refresh them, over a few million years they would erode down to low rolling hills.
What is the most dangerous type of plate boundary?
At convergent plate boundaries, where two continental plates collide earthquakes are deep and also very powerful. In general, the deepest and the most powerful earthquakes occur at plate collision (or subduction) zones at convergent plate boundaries.
What are the effects of divergent plate boundaries?
Effects that are found at a divergent boundary between oceanic plates include: a submarine mountain range such as the Mid-Atlantic Ridge; volcanic activity in the form of fissure eruptions; shallow earthquake activity; creation of new seafloor and a widening ocean basin.
What are examples of divergent plate boundaries?
Examples
- Mid-Atlantic Ridge.
- Red Sea Rift.
- Baikal Rift Zone.
- East African Rift.
- East Pacific Rise.
- Gakkel Ridge.
- Galapagos Rise.
- Explorer Ridge.
Why is living near divergent plate boundaries dangerous?
Answer. Explanation: Most of the hazards that characterize a divergent plate boundaries lie under the ocean but on land the hazards are faults, volcanoes , and the most obvious one; earthquakes. These are also known as conservative boundary because the plates grind past one another, not destroying the lithosphere.
What landforms are created by convergent boundaries?
They are formed when two plates collide, either crumpling up and forming mountains or pushing one of the plates under the other and back into the mantle to melt. Convergent boundaries form strong earthquakes, as well as volcanic mountains or islands, when the sinking oceanic plate melts.
Where does Convergent boundaries occur?
Convergent boundaries occur between oceanic-oceanic lithosphere, oceanic-continental lithosphere, and continental-continental lithosphere. The geologic features related to convergent boundaries vary depending on crust types.
Why do earthquakes occur at convergent plate boundaries?
Convergent plate boundaries The plates move towards one another and this movement can cause earthquakes. This happens because the oceanic plate is denser (heavier) than the continental plate. When the plate sinks into the mantle it melts to form magma. The pressure of the magma builds up beneath the Earth’s surface.
Which is the only plate boundary that doesn’t involve magma?
Transform Boundary
Do convergent boundaries create or destroy crust?
At convergent boundaries, continental crust is created and oceanic crust is destroyed as it subducts, melts, and becomes magma. Convergent plate movement also creates earthquakes and often forms chains of volcanoes.
What will happen if two oceanic plates collide?
When two oceanic plates converge, the denser plate will end up sinking below the less dense plate, leading to the formation of an oceanic subduction zone. Old, dense crust tends to be subducted back into the earth. An example of a subduction zone formed from a convergent boundary is the Chile-Peru trench.
What 2 boundaries make a trench?
In particular, ocean trenches are a feature of convergent plate boundaries, where two or more tectonic plates meet. At many convergent plate boundaries, dense lithosphere melts or slides beneath less-dense lithosphere in a process called subduction, creating a trench.
What are the 5 deepest trenches in the world?
The Five Deeps Expedition was the first to reach the deepest point in each of the Earth’s five oceans: the Puerto Rico Trench in the Atlantic, South Sandwich Trench in the Southern Ocean, Java Trench in the Indian Ocean, Challenger Deep in the Pacific and Molloy Deep in the Arctic.
What are the deepest trenches in the world?
The deepest trench in the world, the Mariana Trench located near the Mariana Islands, is 1,580 miles long and averages just 43 miles wide. It is home to the Challenger Deep, which, at 10,911 meters (35,797 feet), is the deepest part of the ocean.
Are oceanic trenches divergent?
There are three types of lithospheric plate boundaries: divergent (where lithosphere and oceanic crust is created at mid-ocean ridges), convergent (where one lithospheric plate sinks beneath another and returns to the mantle), and transform (where two lithospheric plates slide past each other). …
What is trench rollback?
Trench rollback. This is called trench rollback or hinge retreat (also hinge rollback) and is one explanation for the existence of back-arc basins. Slab rollback occurs during the subduction of two tectonic plates, and results in seaward motion of the trench.