What happens to material that is hotter than its surrounding material deep within the earth?
What happens to material that is hotter than its surrounding material deep within the Earth? The hot material slowly moves up toward the surface.
Why does the elevation of the seafloor decrease?
Why does the elevation of the seafloor decrease from the mid-ocean ridge to the abyssal plain? The oceanic lithosphere cools and becomes denser.
What is the largest of Earth’s concentric zones by volume?
Earth scientists believe that convection currents occur in the interior of the earth in the zone known as the mantle, the largest, by volume, of the earth's three major concentric zones. the other two zones are the crust and the core.
Which layer in the earth is similar to the composition of granite quizlet?
The continental crust is thicker and less dense, and is similar to granite in composition (Si, O, Al, K, and Na). The mantle is made of magnesium, iron and silicon.
Why does magma rise from depth to the surface of the Earth?
Why does magma rise from depth to the surface of the Earth? Answer: Magma rises toward the surface of the Earth because it is less dense than solid rock and buoyant relative to its surroundings. Buoyancy lifts magma upward through denser rock just as buoyancy lifts less dense Styrofoam upward through denser water.
Why does magma rise toward Earth’s surface?
Magma has the tendency to rise because it weighs less than surrounding hard rock (liquids are less dense than solids) and because of the pressure caused by extreme temperature. The pressure is reduced as magma rises toward the surface.
Why are the mid-ocean ridges higher in elevation than the surrounding ocean floor?
Why are the mid-ocean ridges higher in elevation than the surrounding ocean floor? Warmer material near the ridge is less dense, so floats higher on the mantle.
What causes seafloor spreading?
Seafloor spreading occurs at divergent plate boundaries. As tectonic plates slowly move away from each other, heat from the mantle's convection currents makes the crust more plastic and less dense. The less-dense material rises, often forming a mountain or elevated area of the seafloor.
What is the largest of Earth’s concentric zones by volume multiple choice the crust The mantle the core?
The mantle is the largest layer in the earth, making up about 82 percent of the volume and 68 percent of the mass of the earth. The mantle is dominated by magnesium and iron-rich (mafic) minerals. Heat from the core of the earth is transported to the crustal region by large-scale convection in the mantle.
Why oceanic crust is denser?
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.
Why does continental crust stand higher on the mantle than oceanic crust?
The effect of the different densities of lithospheric rock can be seen in the different average elevations of continental and oceanic crust. The less-dense continental crust has greater buoyancy, causing it to float much higher in the mantle.
How do the properties of oceanic crust and continental crust rock differ What happens when they converge?
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 does magma move upwards?
Differences in temperature, pressure, and structural formations in the mantle and crust cause magma to form in different ways. Decompression MeltingDecompression melting involves the upward movement of Earth's mostly-solid mantle. This hot material rises to an area of lower pressure through the process of convection.
What causes magma to rise?
Magma can rise when pieces of Earth's crust called tectonic plates slowly move away from each other. The magma rises up to fill in the space. When this happens underwater volcanoes can form. Magma also rises when these tectonic plates move toward each other.
Why does magma rise towards the Earth’s surface quizlet?
Why does magma tend to rise toward Earth's surface? It is less dense than surrounding rocks.
Why does magma in the mantle rise to the crust above it?
Why does magma in the mantle rise through the crust above it? The liquid magma is less dense than the solid material around it, so it rises.
Why are mid-ocean ridges higher in elevation than the surrounding ocean floor quizlet?
Why are the mid-ocean ridges higher in elevation than the surrounding ocean floor? Warmer material near the ridge is less dense, so floats higher on the mantle.
Why are oceanic ridges elevated?
Oceanic ridges are elevated as new magma cools and becomes more dense. The newly created lithosphere at ridges is cold and therefore occupies less volume and is more dense than hotter rocks. The newly created lithosphere at ridges is hot and therefore occupies more volume and is less dense than cooler rocks.
What causes seafloor spreading quizlet?
The older rock moves outward on both sides of the ridge as new rock forms in the center of the ridge from cooling of molten material. This process is sea floor spreading.
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.
How can continental crust be thicker than oceanic crust yet still float on top of the mantle?
The effect of the different densities of lithospheric rock can be seen in the different average elevations of continental and oceanic crust. The less-dense continental crust has greater buoyancy, causing it to float much higher in the mantle.
Why are oceanic plate heavier than continental plates?
Oceanic plates lie under oceans. They're denser compared to continental crust, meaning they have more mass per unit volume. Continental crust is just the opposite. It's located under land masses and is less dense than oceanic plates.
Which property do you think causes continental crust to have a higher elevation?
The less-dense continental crust has greater buoyancy, causing it to float much higher in the mantle. Its average elevation above sea level is 840 metres (2,750 feet), while the average depth of oceanic crust is 3,790 metres (12,400 feet). This density difference creates two principal levels of Earth's surface.
Why are continents higher than oceanic 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.
Why does continental crust sit higher than oceanic crust quizlet?
Areas of continental crust stand higher than areas of oceanic crust, because continental crust is THICKER and LESS DENSE than oceanic crust. The deepest parts of the ocean are near the continents, and out in the middle of the ocean, the water is relatively shallow.
Why is continental crust higher than oceanic crust?
The less-dense continental crust has greater buoyancy, causing it to float much higher in the mantle. Its average elevation above sea level is 840 metres (2,750 feet), while the average depth of oceanic crust is 3,790 metres (12,400 feet). This density difference creates two principal levels of Earth's surface.
Why oceanic crust is heavier than continental crust?
In the theory of tectonic plates, at a convergent boundary between a continental plate and an oceanic plate, the denser plate usually subducts underneath the less dense plate. It is well known that oceanic plates subduct under continental plates, and therefore oceanic plates are more dense than continental plates.
Which component of magma is the highest and the lowest in value?
Felsic MagmaFelsic magma has the highest silica content of all magma types, between 65-70%. As a result, felsic magma also has the highest gas content and viscosity, and lowest mean temperatures, between 650o and 800o Celsius (1202o and 1472o Fahrenheit).
Why does magma rise toward the Earth’s surface Group of answer choices?
Magma has the tendency to rise because it weighs less than surrounding hard rock (liquids are less dense than solids) and because of the pressure caused by extreme temperature. The pressure is reduced as magma rises toward the surface.
What causes magma to rise to the surface?
As they rise, gas molecules in the magma come out of solution and form bubbles and as the bubbles rise they expand. Eventually the pressure from these bubbles is stronger than the surrounding solid rock and this surrounding rock fractures, allowing the magma to get to the surface.