How does the Seafloor crust differ from continental crust?
Oceanic crust differs from continental crust in several ways: it is thinner, denser, younger, and of different chemical composition. Like continental crust, however, oceanic crust is destroyed in subduction zones. The lavas are generally of two types: pillow lavas and sheet flows.
Why is Earth’s continental crust lower in density than the Seafloor crust?
Why is continental crust lower in density than seafloor crust? Continental crust is made from remelted seafloor crust and therefore only the lower-density material rises to form it.
Why do small worlds have more craters than large worlds?
Smaller planets have less gravitational "pull" than large planets; impactors will strike at lower speeds. The greater the mass of the impactor, the greater the size of crater. Craters most often are circular.
What are the main reasons there are so few impact craters on Earth compared to the Moon quizlet?
There are very few craters on Earth's surface compared to the surface of the Moon. The primary reason for this is: The Earth's surface is continually renewed by geological activity.
Why is the creation of the continental crust more complicated than the creation of the oceanic crust?
Why is the creation of the continental crust more complicated than the creation of the oceanic crust? the continental crust has resulted from more complex, processes of differentiation from the upper mantle driven by thermal energy.
Is the oceanic crust denser than the continental?
Oceanic crust is generally composed of dark-colored rocks called basalt and gabbro. It is thinner and denser than continental crust, which is made of light-colored rocks called andesite and granite.
Why the thickness of the Earth’s crust varies widely between continental masses and the ocean floor?
1. The thickness difference is essentially because the oceanic crust is much younger than continental crust. 2. Additionally the crust below the ocean is constantly being recycled at subduction zones.
Why continental and oceanic crusts differ in their density?
The density of the continental crust is much less as compared to the oceanic crust. It has an approximate value of 2.6 g/cm3. Due to this difference in densities in magma between the oceanic crust and the continental crust, the continents stay in their places, and both crusts are able to float on the magma.
Why does Earth have fewer craters than Venus?
Earth has fewer craters than Venus because erosion and plate tectonics have eroded or removed them from the surface.
Why does Earth have less craters than Mars?
However, very few impact craters on Earth can be seen because Earth's ancient surface has been worn by erosion, covered by lava, and recy- cled by plate tectonics. On the other hand, Mars has a stable crust and small scale, localized resurfacing, so most of the Martian impact craters still exist.
Why are there so many craters on the Moon and so few on Earth select all that apply?
Why are there so many craters on the Moon and so few on Earth? (Select all that apply.) The Moon does not have an active geological cycle, so craters are not destroyed. The Earth's atmosphere causes the breakup and destruction of smaller meteors preventing them from hitting the surface.
Why are there so few craters visible on Earth’s surface today?
So why are there so few craters on Earth? NASA notes that Earth is equipped with three processes that eat up craters relatively quickly: erosion, tectonics, and volcanism. These forces leave only the largest scars from meteorites or asteroids — unlike, say, the moon, which can't gobble up craters.
Why the thickness of the earth crust varies widely between continental masses and the ocean floor?
1. The thickness difference is essentially because the oceanic crust is much younger than continental crust. 2. Additionally the crust below the ocean is constantly being recycled at subduction zones.
Why do the continents sit higher than the ocean?
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.
Why are oceanic plates more dense than continental plates?
Oceanic & Continental Plates The oceanic plate is denser and sinks due to its lower buoyancy. It's sucked into the asthenosphere and is melted deeper into the Earth, called a subduction zone. The continental plate is less dense and floats over the top of it since it is more buoyant.
Why is oceanic crust more dense than continental?
Bassically the Oceanic crust is made with volcanic rocks and intrussions from the Mantle (which is more dense than the crust) and it has densities of about 2.9 grams/cubic centimeter. Continental crust is about 2.7 gr/cc, becase is made from less dense rocks as granites or limestones.
What are the geologic differences between continental plates and oceanic plates?
Continental plates have a lower density than Oceanic plates. Granite and recycled materials are much thinner than the ocean plates' thick basalt layers. Oceanic plates occupy about 71% of the Earth's surface. Continental plates make up 29% of the Earth's surface.
How does a continental plate differ from oceanic?
Continental plates are much thicker that Oceanic plates. At the convergent boundaries the continental plates are pushed upward and gain thickness. The rocks and geological layers are much older on continental plates than in the oceanic plates. The Continental plates are much less dense than the Oceanic plates.
Why does Earth have fewer impact craters?
Understanding Earth The first reason is that Earth's surface is continuously changing because we live on a geologically active planet. Impact craters are relatively shallow, so these “dents” in Earth's rocky crust (the surface bit we can see with our eyes) can be easily buried or wiped out by erosion.
Why are there more craters in certain parts of the world than others?
❖ We conclude that there are more craters in some areas than others because of erosion and the type of rock the surface is made of. ❖ Oceanic Rock (area 1) Any craters would have been eroded away when there was water on Mars. Also, any projectiles would have been cushioned by the water.
Why are impact craters more common on the Moon and Mars than on Earth?
Meteorite craters are more common on the Moon and Mars and on other planets and natural satellites than on Earth, because most meteorites either burn up in Earth's atmosphere before reaching its surface or erosion soon obscures the impact site.
Why does Earth have fewer craters?
So why are there so few craters on Earth? NASA notes that Earth is equipped with three processes that eat up craters relatively quickly: erosion, tectonics, and volcanism. These forces leave only the largest scars from meteorites or asteroids — unlike, say, the moon, which can't gobble up craters.
Why don’t we see as many craters on Earth as we see on the Moon or Mercury?
Mercury and the Moon Impact craters dominate the surfaces of Mercury and the Earth's Moon. Both bodies lack liquid water on their surfaces that would erode impact craters over time. They also lack an atmosphere which, on planets like the Earth and Venus, could disintegrate meteoroids before they impact the surface.
What is the difference between oceanic and continental?
What is the difference between Oceanic and Continental Crust? Oceanic crust is dominated by mafic and ultramafic intrusive igneous rocks whereas continental rocks are dominated by granitic (felsic) intrusive igneous rocks.
What is the difference between oceanic and continental plates?
Continental plates are much thicker that Oceanic plates. At the convergent boundaries the continental plates are pushed upward and gain thickness. The rocks and geological layers are much older on continental plates than in the oceanic plates. The Continental plates are much less dense than the Oceanic plates.
Why are oceanic plates thinner than continental plates?
The answer lies in the composition of the rocks. Continental crust is composed of granitic rocks which are made up of relatively lightweight minerals such as quartz and feldspar. By contrast, oceanic crust is composed of basaltic rocks, which are much denser and heavier.
What is the difference of oceanic oceanic continental oceanic and continental continental?
Oceanic plates are much thinner than continental plates. continental plates. are much thicker than Oceanic plates. At a convergent margin, an oceanic plate collides with a continental plate, forcing the oceanic plate beneath the continental plate and destroying it.
What is the difference between plates and continents?
The continents are embedded in the plates. Many continents occur in the middles of plates, not at their boundaries or edges. Plates also underlie the Earth's oceans. A single plate often includes both continental and oceanic regions.
Which of the following is a factor that helps explain Earth’s lack of craters compared to the Moon?
Factors that help explain Earth's lack of craters compared to the moon. Wind erosion, larger atmosphere, liquid water on surface, active tectonics and volcanism.
Why are impact craters more common on the Moon than on Earth even though the Moon is a much smaller target and has a weaker gravitational field?
Why are impact craters more common on the Moon than on Earth, even though the Moon is a much smaller target and has a weaker gravitational field? Earth has a more substantial atmosphere than the Moon, causing more incoming bolides to burn up in the atmosphere before impact.