How are Minerals and Oil Discovered in the Ground?

The Earth's interior is a reservoir of water, natural gas, and minerals. However, significant effort is required to find out exactly what is deep underground. Scientists have developed many new tools over the years to determine what kinds of minerals exist deep in the earth.

In earlier times, magnetic waves were sent deep into the ground. If these waves struck any metal, an electric current would be generated, and this current would cause a bell in the instrument to ring. Another instrument would emit shock waves of vibration. By measuring the return of these vibration waves after hitting a metal, similar to an echo, the presence of metal or oil in the ground could be determined. After the discovery of infrared photography, minerals were also searched for by projecting infrared rays onto the ground from an airplane. Today, all subsurface information can be obtained using infrared rays from satellites orbiting in space. India's IRS (Indian Remote Sensing) satellites are dedicated to this work.