Answer
The two models of mantle-plate convection are the whole-mantle convection model and the layered convection model.
1. Whole-Mantle Convection Model: In this model, the mantle is envisioned as a single convecting layer, where heat transfer and material circulation occur throughout the entire mantle. It suggests that the convection currents in the mantle extend from the core-mantle boundary to the base of the lithosphere. This model proposes that the movement of the entire mantle is responsible for driving the motion of tectonic plates. The heat generated from the core and the radioactive decay of elements within the mantle create buoyancy forces, leading to mantle convection and plate movement.
2. Layered Convection Model: The layered convection model suggests that the mantle is divided into two distinct layers: the upper mantle and the lower mantle. In this model, convection currents occur separately in these two layers, with limited interaction between them. The upper mantle is considered to be more mobile and involved in the movement of tectonic plates, while the lower mantle exhibits slower and larger-scale convection. The division between the layers is believed to be influenced by the phase changes and density variations within the mantle, such as the transition zone between the upper and lower mantle.
Both models provide different perspectives on how mantle convection contributes to plate tectonics. The whole-mantle convection model emphasizes the importance of mantle-wide circulation, while the layered convection model suggests a more compartmentalized and layered convection system. It is worth noting that the exact nature of mantle convection is still an active area of research, and further studies and observations are needed to refine our understanding of these models and their implications for plate tectonics.
Work Step by Step
The two models of mantle-plate convection are the whole-mantle convection model and the layered convection model.
1. Whole-Mantle Convection Model: In this model, the mantle is envisioned as a single convecting layer, where heat transfer and material circulation occur throughout the entire mantle. It suggests that the convection currents in the mantle extend from the core-mantle boundary to the base of the lithosphere. This model proposes that the movement of the entire mantle is responsible for driving the motion of tectonic plates. The heat generated from the core and the radioactive decay of elements within the mantle create buoyancy forces, leading to mantle convection and plate movement.
2. Layered Convection Model: The layered convection model suggests that the mantle is divided into two distinct layers: the upper mantle and the lower mantle. In this model, convection currents occur separately in these two layers, with limited interaction between them. The upper mantle is considered to be more mobile and involved in the movement of tectonic plates, while the lower mantle exhibits slower and larger-scale convection. The division between the layers is believed to be influenced by the phase changes and density variations within the mantle, such as the transition zone between the upper and lower mantle.
Both models provide different perspectives on how mantle convection contributes to plate tectonics. The whole-mantle convection model emphasizes the importance of mantle-wide circulation, while the layered convection model suggests a more compartmentalized and layered convection system. It is worth noting that the exact nature of mantle convection is still an active area of research, and further studies and observations are needed to refine our understanding of these models and their implications for plate tectonics.
