A Case Study Documenting the use of Magnetic Concentration Data as an Innovative Method of Coastal Monitoring

Abstract

The use of mineral magnetic concentration data as an innovative means of monitoring sediment transport and sediment properties in marine, estuarine and fluvial environments has been well documented in the past. Mineral magnetic measurements are now considered a routine form of analysis when investigating the compositional properties of rocks, sediments and soils (Thompson and Oldfield, 1986; Walden et al., 1999; Mather and Thompson, 1999). Sediment-related analytical data can, however, be strongly affected by particle size effects. For example, it is often the case that the finer a sediment the greater its concentration of pollutants and thus its mineral magnetic concentration. In other words, high magnetic concentration measurements can be associated with large amounts of fine-grained sediments and an inverse relationship with coarse-grained sediments (C.A. Booth et al., 2005). This irregularity in distribution of pollutants between different sediment types and compositions makes it necessary for a correction to be introduced in order to normalise the findings. The need for a correction factor to be introduced means that generally, most methods of practical analysis are relatively time consuming and costly. Recent studies, such as that undertaken by C.A. Booth et al., 2005, have attempted to highlight the advantages of using mineral magnetic concentration data to indicate a correlation between magnetic concentration and particle size. The study suggests that there is considerable potential for using magnetic concentration data as a particle size proxy for particular sedimentary environments (C.A. Booth et al., 2005). Given the speed, low-cost and sensitivity of the method, it may offer some advantages over other compositional signals (C.A. Booth et al., 2005).