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8.1 Definition of subduction zone.

a convergent boundary where oceanic lithosphere is forced down into the asthenosphere under the lithosphere that comprises another, less dense tectonic plate

2.4 How do convection currents cause plate tectonics? Describe the movement of material in the mantle, asthenosphere and lithosphere.

Convection currents describe the rising, spread, and sinking of gas, liquid, or molten material caused by the application of heat. Tremendous heat and pressure within the earth cause the hot magma to flow in convection currents. These currents cause the movement of the tectonic plates that make up the earth's crust.

5.1 What happens at a divergent boundary?

A divergent boundary occurs when two tectonic plates move away from each other. Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earth's mantle to the surface, solidifying to create new oceanic crust. Two plates sliding past each other forms a transform plate boundary.

1.4 How fast are tectonic plates?

Earth's tectonic plates move extremely slow, in places they move less than 2.5 centimeters per year.

5.2 What geological features occur at a divergent boundary?

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.

5.3 What happens when a divergent boundary forms on a continental plate?

Divergent boundaries within continents initially produce rifts, which eventually become rift valleys.Divergent boundaries also form volcanic islands, which occur when the plates move apart to produce gaps that magma rises to fill.

10.2Where do most volcanoes occur? why?

Sixty percent of all active volcanoes occur at the boundaries between tectonic plates. Most volcanoes are found along a belt, called the "Ring of Fire" that encircles the Pacific Ocean. Some volcanoes, like those that form the Hawaiian Islands, occur in the interior of plates at areas called "hot spots."

8.2 Describe the process of subduction

Subduction is a geological process that takes place at convergent boundaries of tectonic plates where one plate moves under another and is forced to sink due to high gravitational potential energy into the mantle. Regions where this process occurs are known as subduction zones

8.3 What causes the subduction to occur?

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.

10.3 What is the Ring of Fire? What type of plate boundary is found here? What process is happening here?

The Ring of Fire was formed as oceanic plates slid under continental plates. Volcanoes along the Ring of Fire are formed when one plate is shoved under another into the mantle - a solid body of rock between the Earth's crust and the molten iron core - through a process called subduction.

1.3 What layer is directly below the tectonic plates?

The asthenosphere is directly below the tectonic plates.

1.2 What layer of the earth are the plates made of?

Plates are made of the lithosphere.

6.2 What geological features occur at a transform boundary?

The broad zone of shearing at a transform plate boundary includes masses of rock displaced tens to hundreds of miles, shallow earthquakes, and a landscape consisting of long ridges separated by narrow valleys. U.S. Geological Survey.

6.3 Give an example of a transform boundary in the United States.

The most famous example of this is the San Andreas Fault Zone of western North America. The San Andreas connects a divergent boundary in the Gulf of California with the Cascadia subduction zone. Another example of a transform boundary on land is the Alpine Fault of New Zealand.

2.1 Definition of convection

The three types of heat transfer are radiation, conduction, and convection.

10.1 Where do most earthquakes occur? Why?

The world's greatest earthquake belt, the circum-Pacific seismic belt, is found along the rim of the Pacific Ocean, where about 81 percent of our planet's largest earthquakes occur.

8.5 Give an example of where subduction is occuring

There are 2 main types of subduction zones: Oceanic-oceanic plate boundaries: If the subducting plate subducts beneath an adjacent oceanic plate, an island arc is formed. Examples include the Aleutians, the Kuriles, Japan, and the Philippines, all located at the northern and western borders of the Pacific plate.

6.1 What happens at a transform boundary?

Transform boundaries are places where plates slide sideways past each other. At transform boundaries lithosphere is neither created nor destroyed. Many transform boundaries are found on the sea floor, where they connect segments of diverging mid-ocean ridges. California's San Andreas fault is a transform boundary.

3.3 How do plate tectonics move at the transform boundary?

Two plates sliding past each other forms a transform plate boundary.Natural or human-made structures that cross a transform boundary are offset—split into pieces and carried in opposite directions. Rocks that line the boundary are pulverized as the plates grind along, creating a linear fault valley or undersea canyon.

8.4 What geological events or features are caused by the process of subduction

Various formations such as mountain ranges, islands, and trenches are caused by subduction and the volcanoes and earthquakes it triggers. In addition to causing earthquakes, subduction can also trigger tsunamis.

2.2 Describe how a convection current forms?

When a liquid or a gas is heated, it's particles move faster. As the particles move faster, they spread apart taking up more space. The density decreases and the heated fluid rises. The opposite happens when a fluid cools. When a fluid cools, its particles move more slowly and pack closer together. They occupy less space and the density decreases. The cooled fluid sinks. The process repeats.

4.1 What happens when an oceanic and continental plate collide? What geologic features occur here?

When an oceanic and a continental plate collide, eventually the oceanic plate is subducted under the continental plate due to the high density of the oceanic plate. Once again a benioff zone forms where there are shallow intermediate and deep focus earthquakes.

4.2 What happens when two oceanic plates collide? What geological features occur here?

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.

1.1Definition of tectonic plates

one of several huge pieces of Earth's crust

7.1 Definition of Seafloor Spreading

the process by which new oceanic lithosphere forms at mid-ocean ridges as tectonic plates pull away from each other

7.4 What geological events or features are caused by the process of Seafloor spreading?

Active plate margins are often the site of earthquakes and volcanoes. Oceanic crust created by seafloor spreading in the East Pacific Rise, for instance, may become part of the Ring of Fire, the horseshoe-shaped pattern of volcanoes and earthquake zones around the Pacific ocean basin.

3.1 How do the plates move at the divergent boundary?

A divergent boundary occurs when two tectonic plates move away from each other. Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earth's mantle to the surface, solidifying to create new oceanic crust.

3.2 How do the plates move at the Covergent boundary?

At convergent plate boundaries, oceanic crust is often forced down into the mantle where it begins to melt. ... Thus, at convergent boundaries, continental crust is created and oceanic crust is destroyed.

2.3 What causes convection in the mantle? Where does the heat come from?

Heat in the mantle comes from the Earth's molten outer core, decay of radioactive elements and, in the upper mantle, friction from descending tectonic plates.

4.3 What What happens when two continental plates collide? What geological features occur here? Give an example of this type of plate boundary.

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. The new magma (molten rock) rises and may erupt violently to form volcanoes, often building arcs of islands along the convergent boundary.

7.2 Describe the process of seafloor spreading.

Seafloor spreading is a geologic process in which tectonic plates—large slabs of Earth's lithosphere—split apart from each other. ... The less-dense material rises, often forming a mountain or elevated area of the seafloor. Eventually, the crust cracks

7.5 Give an example of where Seafloor spreading is occuring.

Seafloor spreading occurs along mid-ocean ridges—large mountain ranges rising from the ocean floor. The Mid-Atlantic Ridge, for instance, separates the North American plate from the Eurasian plate, and the South American plate from the African plate. ... The Mid-Atlantic Ridge, for instance, is a slow spreading center.

7.3 What causes Seafloor spreading to occur?

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.


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