The Gassmann equation is a mathematical formula used in geophysics to relate the elastic properties of a saturated rock to its dry properties. It helps in understanding how fluids within the rock, such as oil or water, affect its seismic response. This equation is particularly useful in the exploration of natural resources, as it allows geoscientists to predict how changes in fluid saturation can influence the rock's behavior under stress. By applying the Gassmann equation, researchers can estimate the bulk modulus of a saturated rock, which is crucial for interpreting seismic data. This information aids in identifying potential reservoirs and assessing their viability for extraction. Overall, the equation plays a significant role in the field of petrophysics and resource management.