Which statement is true about all convection currents?
A. It results to formation of valleys and hills
B. It causes earthquakes
C. It happen in all layers of the earth
D. It is made possible by heat and pressure
D. It is made possible by heat and pressure
C. It happen in all layers of the earth
To determine which statement is true about all convection currents, let's analyze each option:
A. It results in the formation of valleys and hills: This statement is not true. Convection currents are a process of heat transfer through the movement of a fluid (liquid or gas) caused by temperature differences. While the movement of tectonic plates can result in the formation of valleys and hills, it is not directly caused by convection currents.
B. It causes earthquakes: This statement is not true. Earthquakes are primarily caused by the movement and interaction of tectonic plates, not convection currents. However, it is important to note that convection currents within the Earth's mantle can indirectly influence plate movements, which may contribute to the occurrence of earthquakes along plate boundaries.
C. It happens in all layers of the Earth: This statement is not true. While convection currents do occur in some layers of the Earth, such as the mantle, they are not present in all layers. For example, convection currents do not occur in the solid inner core of the Earth.
D. It is made possible by heat and pressure: This statement is true. Convection currents are driven by differences in temperature and density within a fluid. When a fluid is heated, it becomes less dense and rises, while the cooler and denser fluid sinks. This cycle creates a continuous flow of the fluid, known as a convection current.
Therefore, the correct statement is: "D. It is made possible by heat and pressure."