Final answer:
Normal faulting is a way regional elevation can be increased by causing uplift and increasing the elevation of a region.
Step-by-step explanation:
Regional elevation can be increased through normal faulting. Normal faulting occurs when the crust is pulled apart, causing one block to move down relative to the other block. This movement can create uplift and increase the elevation of the region. For example, the Basin and Range Province in the western United States is characterized by normal faulting and has high-elevation mountain ranges due to this process.
Eroding material from the top does not increase regional elevation. In fact, it can reduce elevation over time as the material is removed.
Thinning the crust does not increase elevation either. Thinning the crust tends to decrease elevation as the crust becomes less resistant to forces that can cause uplift.
Heating the crust and mantle can result in the formation of magma and volcanic activity, but it does not directly increase regional elevation.