Glacio-Volcanism

Where volcano’s sit below an ice mass a unique interactions occurs. Active subglacial volcanism has a variety of societal and environmental implications, ranging from localised natural hazards to ice-sheet scale mas balance and its associated impact on sea level changes. I am currently using ground-based radar to understand these interactions and to understand the various processes relating to glacio-volcanism.

How do subglacial volcano’s influence glaciers and ice caps?

On the one hand, volcano’s that erupt beneath glaciers can cause complete destruction of an ice mass, generating giant ash clouds and can cause significant melting that causes a negative mass balance for that year. The processes leading to these eruptions and those in the aftermath of them are not well understood. By using ground-based radar we will try to understand the impact volcano’s have on glaciers, with a specific focus on Iceland. For example, ice cauldrons (surface depressions) form due to basal melting, but the origin of the melting and the evolution of such features over time are not well constrained. Using high resolution radar measurements we will look to understand these processes from a unique perspective. By measuring surface elevation changes and changes in outlet glaciers we will investigate these processes in detail.

How do glaciers influence volcanism and how will this evolve in the future?

The retreat of ice globally reduces pressure on the underlying crust and causes isostatic readjustment. This pressure reduction encourages active volcanism and increases the likelihood of an volcanic eruption to occur. It is not known if this ‘ice unloading’ effect is aiding the current pattern of volcanism in glaciated regions but this process has been suggested to encourage volcanism in the past. Better measurements of subglacial volcanism, particularly by analysing the overlying ice dynamics, will help to understand these processes and understand how they will evolve in the future.