How does the rate of plate tectonics activity affect sea level?
when rates of volcanism are low, rocks tend to cool faster and sea levels drop as subsidence occurs. conversely, when rates of volcanism are high, it takes longer for the rocks to cool, and sea level remains higher for longer periods of time after the rate of volcanism subsides.
What would happen if the rate of seafloor spreading was faster than the rate of subduction?
What would happen if the rate of seafloor spreading was faster than the rate of subduction? The Earth would grow larger.
What is the rate of seafloor spreading?
These age data also allow the rate of seafloor spreading to be determined, and they show that rates vary from about 0.1 cm (0.04 inch) per year to 17 cm (6.7 inches) per year. Seafloor-spreading rates are much more rapid in the Pacific Ocean than in the Atlantic and Indian oceans.
Why do seafloor spreading rates change?
1 Answer. The seafloor changes because of the earth plates moving causing magma to spew in the water. The magma is then pushed outward causing the seafloor to move and change.
What causes the sea level to increase?
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 are the 3 causes of sea level rise?
Most of the observed sea-level rise (about 3 mm per year) is coming from the meltwater of land-based ice sheets and mountain glaciers, which adds to the ocean's volume (about 2 mm per year combined), and from thermal expansion, or the ocean water's expansion as it warms (roughly 1 mm per year).
What are the effects of seafloor spreading?
Mid-ocean ridges and seafloor spreading can also influence sea levels. As oceanic crust moves away from the shallow mid-ocean ridges, it cools and sinks as it becomes more dense. This increases the volume of the ocean basin and decreases the sea level.
How can 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.
How does seafloor spreading affect the earth?
Seafloor spreading creates new crust. Subduction destroys old crust. The two forces roughly balance each other, so the shape and diameter of the Earth remain constant.
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.
How does sea level change?
Sea level rise is caused primarily by two factors related to global warming: the added water from melting ice sheets and glaciers and the expansion of seawater as it warms. The first graph tracks the change in sea level since 1993 as observed by satellites.
What are the effects of sea level rise?
Sea level rise poses a serious threat to coastal life around the world. Consequences include increased intensity of storm surges, flooding, and damage to coastal areas. In many cases, this is where large population centers are located, in addition to fragile wildlife habitats.
What factors affect sea level?
Sea level rise at specific locations may be more or less than the global average due to many local factors: subsidence, upstream flood control, erosion, regional ocean currents, variations in land height, and whether the land is still rebounding from the compressive weight of Ice Age glaciers.
What causes sea level changes?
Sea level rise is caused primarily by two factors related to global warming: the added water from melting ice sheets and glaciers, and the expansion of seawater as it warms.
What is seafloor spreading and why is it important?
Seafloor spreading is the mechanism by which new oceanic lithosphere is created at and moves away from divergent plate boundaries. The seafloor spreading hypothesis led to one of the most important paradigm shifts in the history of the Earth sciences, the plate tectonics scientific revolution.
What would happen if the seafloor stopped spreading?
If all volcanism stops, so does sea floor spreading—and thus plate tectonics as well. And if plate tectonics stops, Earth eventually (through erosion) loses most or all of the continents where most terrestrial life exists. In addition, CO2 is removed from the atmosphere via weathering, causing our planet to freeze.
Is sea floor spreading constructive or destructive?
The mid-Atlantic ridge is where new ocean floor is made, causing North America and Europe to be moving apart. When the plates move apart, magma flows up between them. It cools and forms new crust. This is why divergent boundaries are also called constructive boundaries.
What does seafloor spreading tell us about our ocean and continents?
Significance. Seafloor spreading helps explain continental drift in the theory of plate tectonics. When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere.
What happens when the sea level rises?
Sea level rise poses a serious threat to coastal life around the world. Consequences include increased intensity of storm surges, flooding, and damage to coastal areas. In many cases, this is where large population centers are located, in addition to fragile wildlife habitats.
What are the 3 causes of sea-level rise?
Most of the observed sea-level rise (about 3 mm per year) is coming from the meltwater of land-based ice sheets and mountain glaciers, which adds to the ocean's volume (about 2 mm per year combined), and from thermal expansion, or the ocean water's expansion as it warms (roughly 1 mm per year).
What is causing the 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 causes sea level to decrease?
During cold-climate intervals, known as glacial epochs or ice ages, sea level falls because of a shift in the global hydrologic cycle: water is evaporated from the oceans and stored on the continents as large ice sheets and expanded ice caps, ice fields, and mountain glaciers.
Why does sea level rise and fall?
Global sea level is rising from two primary causes: the expansion of ocean water as it warms; and increased melting of land-based ice, like glaciers and ice sheets in Greenland and Antarctica and other “upland” areas. As the ocean and the atmosphere continue to warm, water levels will continue to rise.
How does seafloor spreading affect life?
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. Seafloor spreading is a truly wild natural phenomenon that is constantly being monitored and researched.
Why is seafloor spreading important?
Today it refers to the processes creating new oceanic lithosphere where plates move apart. Seafloor spreading replaces the lithosphere destroyed by subduction, and exerts important influences on Earth's chemical and biological evolution.
Does the Earth get bigger because of seafloor spreading?
New crust is continually being pushed away from divergent boundaries (where sea-floor spreading occurs), increasing Earth's surface. But the Earth isn't getting any bigger.
How does sea level rising affect us?
As sea levels rise, coastal communities can expect more frequent and more severe flooding from high tides and storm surges. Over time, such flooding will damage roads, bridges, buildings, and other infrastructure and will lower property values. Many coastal communities are already seeing effects of rising seas.
How does sea level rise affect us?
As sea levels rise, coastal communities can expect more frequent and more severe flooding from high tides and storm surges. Over time, such flooding will damage roads, bridges, buildings, and other infrastructure and will lower property values. Many coastal communities are already seeing effects of rising seas.
What causes changes in sea level?
Global sea levels are rising as a result of human-caused global warming, with recent rates being unprecedented over the past 2,500-plus years. Sea level rise is caused primarily by two factors related to global warming: the added water from melting ice sheets and glaciers and the expansion of seawater as it warms.
Is the Earth shrinking or expanding?
Thanks to our leaky atmosphere, Earth loses several hundred tons of mass to space every day, significantly more than what we're gaining from dust. So, overall, Earth is getting smaller.