Crustal structure refers to the arrangement and composition of layers within the Earth's crust, which is the outermost solid layer of the Earth. This area of research aims to understand the properties and characteristics of the Earth's crust, such as its thickness, density, and composition. Scientists study crustal structure using various techniques, including seismic imaging, gravity surveys, and borehole data. By investigating crustal structure, researchers can gain insights into the geological processes that shape the Earth's surface, as well as the distribution of resources such as minerals and fossil fuels. Additionally, understanding crustal structure is essential for predicting and mitigating natural hazards such as earthquakes and volcanic eruptions.