How Do Plates Move at Divergent Plate Boundaries: A Quizlet Guide to Understanding Plate Tectonics
What are divergent plate boundaries?
Divergent plate boundaries occur where two tectonic plates are being pulled apart from one another. As the plates are being pulled apart, magma rises to fill the gap between them and eventually cools and solidifies, resulting in the formation of new crust. These boundaries are often marked by volcanic activity, with lava erupting from the cracks in the earth’s surface.
The movement of the plates at divergent plate boundaries is caused by tensional forces that are pulling them apart. These forces are often the result of convection currents in the earth’s mantle, which cause the plates to move in different directions. As the plates move away from each other, the gap between them widens and magma rises up to fill the void.
There are several different types of divergent plate boundaries, including mid-ocean ridges, where new oceanic crust is formed and rift valleys, where continents are being pulled apart. Mid-ocean ridges are found in all of the world’s oceans and are the most extensive divergent plate boundaries on the planet. Rift valleys are found on land and can be seen in places like the Great Rift Valley in Africa.
At mid-ocean ridges, the magma that rises up to fill the gap between the plates eventually cools and solidifies, creating new oceanic crust. The newly formed crust then moves away from the ridge in both directions. Over time, this process results in the widening of the ocean basin and the creation of new ocean floor.
In contrast, at rift valleys, continental crust is being pulled apart and new crust is formed in the gap that is created. The formation of new crust at rift valleys can eventually lead to the creation of new oceans if the rifting process continues for a long enough period of time.
In summary, divergent plate boundaries occur where two tectonic plates are moving away from each other, resulting in the formation of new crust due to volcanic activity. These boundaries are often characterized by mid-ocean ridges or rift valleys and are caused by tensional forces resulting from convection currents in the earth’s mantle.
What causes plates to move at divergent plate boundaries?
Plate tectonics is the theory that explains how the Earth’s lithosphere is divided into several large plates that float on top of the hot molten mantle layer beneath. There are three types of plate boundaries, divergent, convergent, and transform. Here we will focus on divergent plate boundaries and what causes the plates to move away from each other.
Divergent boundaries are locations where tectonic plates move away from each other. At these boundaries, new crust is formed as magma rises from the mantle and solidifies, pushing the plates apart. This process is known as seafloor spreading and happens at an average rate of 2.5 centimeters per year.
The force behind seafloor spreading is the upwelling of hot mantle material, which creates a convection current. This current moves the plates apart as the heated material rises and cools, creating a cycle of movement. The force of gravity also plays a role in this process, as the denser older crust sinks beneath the younger, less dense crust.
The process of plate movement at divergent boundaries is known as tensional stress. As the plates are pulled away from each other, they pull the lithosphere apart, creating a gap or rift in the earth’s surface. This gap is often filled with magma, forming new land masses, such as mid-oceanic ridges, or volcanic islands, such as Iceland.
The direction of plate movement at a divergent boundary is determined by the orientation of the boundary. If the boundary is perpendicular to the direction of the convection current, the plates move directly away from each other. This type of divergent boundary is known as a constructive boundary, as it creates new landforms.
If the boundary is at an angle to the convection current, the plates move in a diagonal direction. This type of divergent boundary is known as an oblique boundary. While it still creates new landforms, it can also lead to seismic activity and earthquakes, as the plates move in different directions.
In conclusion, divergent plate boundaries are locations where plates move away from each other due to the upwelling of hot mantle material. This process, known as seafloor spreading, creates new crust and new landforms, including mid-oceanic ridges and volcanic islands. The force behind this process is a combination of convection currents and the force of gravity, which pull the lithosphere apart. Understanding the movements at divergent plate boundaries is essential to understanding the dynamic nature of the earth’s geological processes.
How does magma contribute to plate movement?
Divergent plate boundaries occur where two tectonic plates move away from each other, creating a gap or rift. Beneath this rift is the mantle, which is the layer of molten rock that lies beneath the Earth’s crust. When the plates move apart, magma rises from the mantle and fills the gap created by the separation. This process is known as partial melting and results in the formation of new crust. The new crust then cools and hardens, creating seafloor or oceanic crust.
Magma is a mixture of molten rock, minerals, and gases. It is less dense than the surrounding solid rock, which allows it to rise and fill the gap created by the divergent plate boundary. Magma is created by the melting of rock in the mantle, which is caused by the high temperatures and pressure in the Earth’s interior.
The movement of the plates at divergent boundaries is driven by the pressure of the new magma that is being injected into the gap. The magma exerts a force on the plates, pushing them apart and causing them to move in opposite directions. As the plates move apart, more magma rises up to fill the gap, creating new crust and driving the movement of the plates. Over time, the new crust cools and becomes more dense, causing it to sink back into the mantle and recycle itself back into the Earth’s interior.
In addition to driving plate movement, magma at divergent plate boundaries can also lead to volcanic activity. As the magma rises up to the surface, it can cause eruptions and the formation of new volcanoes. However, most of the volcanic activity at divergent boundaries occurs underwater, resulting in the formation of underwater volcanoes or seamounts.
Overall, magma plays a critical role in driving plate movement at divergent plate boundaries. Without the constant injection of new magma, the plates would not be able to move apart and create new crust. The study of plate tectonics and the role of magma in plate movement is essential to our understanding of the Earth’s geology and its evolution over time.
What types of landforms are found at divergent plate boundaries?
Divergent plate boundaries are characterized by the separation of two tectonic plates that move away from each other. The process of separation results in a gap that is bridged by magma that rises from the mantle, and the solidification of this magma leads to the formation of different landforms. These landforms include oceanic ridges, rifts, and valleys, as well as volcanic activity that can give rise to underwater volcanoes, hot springs, and geysers.
Oceanic ridges are long mountain chains that form in the middle of the ocean floor where two tectonic plates are moving away from each other. As the plates move apart, hot mantle material rises and melts, and then solidifies to form new crust. This process results in the formation of the ridge, which appears as a chain of underwater mountains with deep valleys in-between.
Rifts and valleys are other types of landforms that can be found at divergent plate boundaries. Rifts are linear valleys that form when two plates start to move away from each other, and can be found on both continents and ocean floor. The Great Rift Valley in East Africa is an example of a continental rift valley, while the Mid-Atlantic Ridge is an example of an oceanic rift valley.
Volcanic activity is also a common feature at divergent plate boundaries. As the plates move apart, magma from the mantle is pushed upward, and then solidifies at the surface to form volcanoes. These volcanoes can be found both on land and under water, and are often associated with fissure eruptions and earthquakes. The volcanic activity that occurs at divergent plate boundaries can create new land and modify the existing landscape significantly.
Overall, the landforms that are found at divergent plate boundaries are constantly changing due to the continuous movement of two tectonic plates. The formation of new crust, volcanic activity, and movement of landmasses can all occur at these boundaries, and can have a significant impact on the geology and geography of our planet.
What happens at divergent plate boundaries?
At divergent plate boundaries, tectonic plates move away from each other. This results in the formation of new crust, which contributes to the growth of the Earth’s surface. Divergent boundaries are mostly found at mid-ocean ridges, where new oceanic crust is formed as magma rises from the mantle and solidifies.
What is the impact of divergent plate boundaries on the environment?
One of the most significant impacts of divergent plate boundaries is the creation of new ocean basins. This process also contributes to the movement of continents and the formation of new terrain. The growth of new crust also brings about changes in landscapes and habitats, leading to the formation of new ecosystems.
What are the dangers associated with divergent plate boundaries?
Although divergent plate boundaries contribute to the creation and growth of the Earth’s surface, they also pose some risks to human life. The splitting of the crust during plate separation can lead to volcanic eruptions and earthquakes. These natural disasters can lead to casualties and destruction of infrastructure. In areas where volcanic activity is concentrated, there may also be chances of lava flows and sudden volcanic explosions.
How do divergent plate boundaries affect the global climate?
One of the most significant long-term effects of divergent plate boundaries is the changes they bring about in the global climate. As new crust is formed, magma rises from the mantle, causing the release of large amounts of carbon dioxide into the atmosphere. This increase in carbon dioxide levels can lead to significant changes in the Earth’s climate, including global warming, rising sea levels, and changes in ocean currents.
What is the significance of divergent plate boundaries in the study of geology?
Divergent plate boundaries are crucial to the study of geology since they provide scientists with valuable information about the formation and evolution of the Earth’s surface. The movement of tectonic plates over millions of years can help discover the history of geological events that have taken place in the past. By analyzing the magma and rocks that are formed at divergent plate boundaries, scientists can gain insights into the composition of the mantle and the processes that shape the surface of the Earth.
