Description:
Estimating magnetic properties of water samples by first measuring the Anhysteretic Remanent
Magnetization (ARM) before Isothermal Remanent Magnetization (IRM) is induced has been costly
due to the discard of samples measured by staring with the latter before the former. However, no
clear understanding exists on the effect of measuring magnetic properties values by first inducing
IRM before ARM. This study explored the effect of measuring concentration related parameters
(χlf, χfd and χARM), a mineral related parameter (S−300) and grain size parameters (χfd% and
χARM/SIRM ratio) from water samples by starting with IRM before ARM. Forty three surface water
samples were collected from the estuarine of Yangtze River (China) with the aim of measuring
magnetic characteristics by starting with IRM before ARM. The results indicated that, measuring
magnetic properties by either starting with ARM or IRM led to similar values for χlf, χfd, χfd%,
χARM, S−300 and χARM/SIRM ratio (p > 0.05). These results imply that, measuring concentration
related parameters does not necessarily require measuring ARM first and then IRM. Researchers
can start by measuring any parameter between ARM and IRM without affecting the final results of
the water samples, but with proper demagnetization when started with IRM.