Formation of magmatic brine lenses via focussed fluid-flow beneath volcanoes

- Magmatic brine lenses are likely to form a few km beneath active or dormant volcanoes.
- Formation of brine lenses is investigated by means of numerical modelling.
- Conditions favouring lens formation include a high permeability conduit.
- Brine lenses can endure millions of years after cessation of magma degassing.
- Magnetotelluric images of volcano subsurfaces are similar to the modelling results.