Surface magnetic resonance

Magnetic field sensing - Surface magnetic resonance (SMR)

Surveying is the analysis and recording of the characteristics of an area which is found on, above or below Earth. Different categories exist, such as geophysical surveying which may focus on subsurface features such as rock structure, water or petroleum resources and other. Surveying may use electromagnetic techniques such as surface magnetic resonance (also known as magnetic resonance sounding) and ground-probing RADAR.

Text below is derived from video at link https://youtu.be/vnP0whY5Pos.

"Surface magnetic resonance (SMR) surveys measure the water content of rocks beneath the ground.

A loop of cable is arranged over an area. An electrical current is run through the loop. This creates a magnetic field.

The magnetic field excites water molecules in the rocks.

The electric current is then switched off."

The excited water molecules relax by emitting a signal.

"The loop detects the signal from the excited water molecules.

The data is processed to indicate the presence, depth and amount of water in the rock.

The data can be used to discover groundwater resources."

Figure 1: Image from video https://youtu.be/vnP0whY5Pos depicting the principle of surface magnetic resonance.