# ESCO 2020 TALK: THE ROLE OF GRANULAR MECHANICS AND POROUS FLOW FOR ICE SHEET BEHAVIOR 

[1]ESCO 2020, the 7th European Seminar on Computing, was held between June 8
and 12.  I presented my current research on ice-sheet and sediment mechanics.

Full abstract:

    Title: The role of granular mechanics and porous flow for ice
    sheet behavior in a changing climate

    Ice sheets and glaciers commonly flow over sedimentary deposits, in
    particular in areas of fast ice flow. The basal sediments are weakened by
    high water pressure provided by ice melt and limited drainage. Areas of
    fast flow are primary contributors to sea-level rise, so an accurate
    understanding of the thermomechanical multiphysics problem of ice, water,
    and sediment is crucial for predicting dynamical behavior under future
    climate scenarios. The in-situ observational basis from borehole
    measurements shows that the subglacial environment is highly dynamic. Water
    pressures, strain rate, and glacial sliding patterns are extremely variable
    in time and space, and hint towards significant complexity beyond current
    modelling approaches. Sediment transport by ice flow reshapes the bed, and
    can feed back to the ice flow physics. In this presentation I explain our
    efforts to numerically describe the subglacial sediment mechanics and fluid
    dynamics, and how the processes affect ice sheet behavior. GPU-based
    particle-scale simulations using the discrete element method and porous
    fluid dynamics provide detailed insight into sediment and meltwater
    dynamics. However, the intense computational requirements severely limit
    their applicability to coupled simulations of ice and bed. Our newest
    efforts use continuum models of non-local granular fluidity to simulate
    essential behavior on larger spatial and temporal scales. We show that the
    variability observed in field borehole measurements can be explained by
    considering the coupled dynamics of the ice-water-sediment system. From
    these dynamics ice flow has the ability to rapidly reshape its bed,
    providing additional feedbacks to ice contribution to sea level in a
    changing climate.

Slides and video below:

  - slides: https://adamsgaard.dk/npub/esco2020-damsgaard.pdf
  - video: https://adamsgaard.dk/video/damsgaard_esco2020.mp4


References:

[1] https://www.esco2020.femhub.com/