What is the subsurface estate that may be severed from the surface estate?

The subsurface estate refers specifically to the rights associated with minerals located beneath the surface of a property. In Alabama, as in many other states, the mineral estate can be separated or severed from the surface estate. This means that one party can own the land above while another party holds rights to the minerals below, such as oil, gas, coal, or other natural resources. This separation allows for different interests and uses of the land, facilitating activities like mining or drilling while the surface can be developed for residential, agricultural, or commercial use.

While air space refers to the space above the surface estate, it does not pertain to subsurface rights. Prescriptive and subservient designations relate more to the rights and burdens associated with property use but do not specifically refer to the rights associated with physical minerals found beneath the land. Thus, the mineral estate is indeed the correct answer, as it directly relates to the subsurface rights that can exist independently from surface rights.