What happens when the seafloor spreading is greater than the subduction?
Subduction happens where tectonic plates crash into each other instead of spreading apart. At subduction zones, the edge of the denser plate subducts, or slides, beneath the less-dense one. The denser lithospheric material then melts back into the Earth's mantle. Seafloor spreading creates new crust.
How does the rate of seafloor spreading affect sea level?
The increased rate of seafloor spreading caused sea level to rise. Increasing the rate of seafloor spreading inflates the ridge. Hot, young lithosphere is forming and moving away from the ridge at a faster rate and moves a greater distance from the ridge before it cools and contracts.
Where is the rate of seafloor spreading greatest?
the Pacific Ocean Seafloor-spreading rates are much more rapid in the Pacific Ocean than in the Atlantic and Indian oceans. At spreading rates of about 15 cm (6 inches) per year, the entire crust beneath the Pacific Ocean (about 15,000 km (9,300 miles) wide) could be produced in 100 million years.
Does seafloor spreading happen at a constant rate?
Seafloor spreading is mainly the result of convection currents dragging the ocean plate along with them, but that is not the only force pushing (or pulling) the seafloor, nor does it necessarily occur at a constant rate.
What happens at a 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.
What is seafloor spreading quizlet?
sea-floor spreading. the process by which molten material adds new oceanic crust to the ocean floor.
How does the rate of seafloor spreading affect sea level quizlet?
How does the rate of seafloor spreading affect the sea level? Faster spreading produces broader ridges that displace water and expand the oceans.
How does spreading rate affect volume of a ridge?
Additionally, if seafloor spreading rates are increased, the amount of young, topographically elevated ridges is increased relative to the slower, older topographically lower ridges that occupy a smaller volume.
How does seafloor spreading affect the earth?
Seafloor spreading can also drastically change sea levels. When oceanic crust parts ways with mid-ocean ridges, they can sometimes sink even lower than before, which can actually lower the sea level.
What is the rate of seafloor spreading?
As a general rule, fast ridges have spreading (opening) rates of more than 90 mm/year. Intermediate ridges have a spreading rate of 40–90 mm/year while slow spreading ridges have a rate less than 40 mm/year. The highest known rate was over 200 mm/yr during the Miocene on the East Pacific Rise.
How do differences in density and temperature cause sea floor spreading and subduction?
1 Answer. The cooler denser mantle sinks causing subduction and the hotter mantle rises to the surface causing sea floor spreading.
What happens at a subduction zone quizlet?
The region where an oceanic plate sinks down into the asthenosphere at a convergent boundary, between continental and oceanic plates. Where two plates are moving apart, magma comes up to create new crust. A geologic feature in the seafloor produced by the descending plate during subduction.
What will form above subduction zone?
Magma formed above a subducting plate slowly rise into the overriding crust and finally to the surface forming a volcanic arc, a chain of active volcanoes which parallels the deep ocean trench.
What process causes subduction and seafloor spreading?
Seafloor spreading and other tectonic activity processes are the result of mantle convection. Mantle convection is the slow churning motion of Earth's mantle.
Where does subduction occur?
Subduction zones are where the cold oceanic lithosphere sinks back into the mantle and is recycled. They are found at convergent plate boundaries, where the oceanic lithosphere of one plate converges with the less dense lithosphere of another plate.
Which of the following would cause sea level to rise?
The two major causes of global sea level rise are thermal expansion caused by warming of the ocean (since water expands as it warms) and increased melting of land-based ice, such as glaciers and ice sheets.
What is the primary reason that an increase in glaciers on land would cause sea level to fall?
What is a primary reason an increase in glaciers on land would cause sea level to fall? the erosive effects of waves.
What happens to the ocean if there are more mid-ocean ridges that subduction zones?
New seafloor is generated from the upper mantle at the mid-oceanic ridges, spreads laterally outward, and is eventually subducted, or consumed, at the margins of ocean basins. Subduction may also occur between two regions of oceanic crust, with older, denser sections underthrusting younger, less-dense ones.
How does seafloor spreading affect the environment?
The rate of spreading determines how much CO2 is released to the atmosphere. When seafloor spreading speeds up, more lava is produced, causing more CO2 to be released into the atmosphere, promoting global warming.
What would happen if the rate of seafloor spreading was faster?
What would happen if the rate of seafloor spreading was faster than the rate of subduction? The Earth would grow larger.
How does density affect subduction?
The cooler denser mantle sinks causing subduction and the hotter mantle rises to the surface causing sea floor spreading.
What happens at a subduction zone boundary?
These plates collide, slide past, and move apart from each other. Where they collide and one plate is thrust beneath another (a subduction zone), the most powerful earthquakes, tsunamis, volcanic eruptions, and landslides occur.
What do subduction zones cause?
Where they collide and one plate is thrust beneath another (a subduction zone), the most powerful earthquakes, tsunamis, volcanic eruptions, and landslides occur.
What happens during a subduction?
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the heavier plate dives beneath the second plate and sinks into the mantle.
What process causes subduction?
Subduction occurs when two plates collide at a convergent boundary, and one plate is driven beneath the other, back into the Earth's interior. Not all convergence leads to subduction. Continental rocks are too buoyant to be forced downward, so when continents collide, they crumple but stay at the surface.
What causes subduction?
These plates collide, slide past, and move apart from each other. Where they collide and one plate is thrust beneath another (a subduction zone), the most powerful earthquakes, tsunamis, volcanic eruptions, and landslides occur.
What is the result of subduction?
These plates collide, slide past, and move apart from each other. Where they collide and one plate is thrust beneath another (a subduction zone), the most powerful earthquakes, tsunamis, volcanic eruptions, and landslides occur.
What is subduction what happens when it occurs?
Subduction occurs when two plates collide at a convergent boundary, and one plate is driven beneath the other, back into the Earth's interior. Not all convergence leads to subduction. Continental rocks are too buoyant to be forced downward, so when continents collide, they crumple but stay at the surface.
What cities will be underwater in 2050?
There are numerous heavily populated sinking cities like Mumbai, Shanghai, NYC, and Miami at risk. With a population of 10 million, Jakarta is considered by some to be “the fastest-sinking city in the world” and is projected to be “entirely underwater by 2050”.
What will sea levels look like in 2050?
By 2050, the average rise will be 4 to 8 inches along the Pacific, 10 to 14 inches along the Atlantic, and 14 to 18 inches along the Gulf.