Different soil types induces different magnetism. For example, clay has the least magnetic field while sand has the highest amount. The major component that forms the variations in physical propoerties of the soil is due to the variations of iron mineral forms and distributions as mentioned by Maher in his article, Characterisation of Soils by Mineral Magnetic Measurements.
I downloaded a magnetometer app to compare the different magnetic field of different environment.
UK’s position at the 50 degree latitude results in a magnetic field that range around 50 microtesla.
I compared some extreme environments within the house. It shows 47 microtesla for the normal environment. When i head closer to the refrigerator, it showed a spike of 96 microtesla.
I went further to the compare the different soil magnetic field. Clay gives a significant lower amount when compared to rocks. The initial hypothesis that i can conclude from this is that the larger the particles, the higher its magnetic field will be.
Clay – 30 microtesla Silt – 40 microtesla Rock – 50 microtesla
Next, I will be further exploring on the patterns of the steel dust with magnet in relation to soil.