Reactive flow instabilities

Reactive fluid flows in a porous medium are often unstable. Focussed fluid flow can dissolve the porous matrix, leading to faster flow, a positive feedback.

This type of instability is thought to explain the formation of brine channels in sea ice the dunite channels in the mantle. These channels can be seen at the Earth’s surface, for example in Oman (pictured).

I use a mixture of theoretical stability analysis and numerical modelling to understand the behaviour of channelized fluid flow. I have applied this to:

• Brine channels in sea ice, developing simplified models of the nonlinear system (Rees Jones and Worster, 2013a, Rees Jones and Worster, 2013b).
• Dunite channels in the mantle, particularly to understand the role of bulk deformation of the system (Rees Jones and Katz, 2018).