New random models for geological variables

Figure 1. Realisation  of a random model which emulates the spatial variation of soil formed in  material disturbed by the formation of ice wedges during the last glaciation

Statistical modelling exploits the properties of random variables that can be used to emulate the spatial variation of geological observations.

The selection of an appropriate random variable is important, and we put a lot of effort into testing that a particular random variable is appropriate for our geological data — more about distinguishing spatially correlated random variation; linear mixed model with non-stationary mean and covariance

Often the normal random variable, the well-known bell curve, is appropriate; but it is not suitable for all geological phenomena, particularly for those influenced by deposits with complex geometry.

We have initiated research into random variables that arise in an area of mathematics called stochastic geometry. We are trying to discover whether stochastic geometry allows us to use geological knowledge to develop random variables that are suitable for our purposes — more about stochastic geometric model for continuous local trends in soil variation.

In collaboration with colleagues at Ghent University we have shown that a stochastic geometric model of soil formed in Pleistocene cover sands in a part of Belgium describes the spatial variation better than the standard normal model.

The picture below shows an example of the random variation generated by the fitted model. The yellow areas correspond to the network of ice-wedges that formed in the soil during the last glaciation.

Contact

Contact Dr Murray Lark for more information