006-esco2020.html (2579B)
1 <p><a href="https://www.esco2020.femhub.com/">ESCO 2020</a>, the 2 7th European Seminar on Computing, was held between June 8 and 12. 3 I presented my current research on ice-sheet and sediment mechanics. 4 Full abstract:</p> 5 6 <blockquote> 7 <b>The role of granular mechanics and porous flow for ice sheet behavior in a changing climate</b> 8 <br><br> 9 Ice sheets and glaciers commonly flow over sedimentary deposits, 10 in particular in areas of fast ice flow. The basal sediments are 11 weakened by high water pressure provided by ice melt and limited 12 drainage. Areas of fast flow are primary contributors to sea-level 13 rise, so an accurate understanding of the thermomechanical multiphysics 14 problem of ice, water, and sediment is crucial for predicting 15 dynamical behavior under future climate scenarios. The in-situ 16 observational basis from borehole measurements shows that the 17 subglacial environment is highly dynamic. Water pressures, strain 18 rate, and glacial sliding patterns are extremely variable in time 19 and space, and hint towards significant complexity beyond current 20 modelling approaches. Sediment transport by ice flow reshapes the 21 bed, and can feed back to the ice flow physics. In this presentation 22 I explain our efforts to numerically describe the subglacial sediment 23 mechanics and fluid dynamics, and how the processes affect ice sheet 24 behavior. GPU-based particle-scale simulations using the discrete 25 element method and porous fluid dynamics provide detailed insight 26 into sediment and meltwater dynamics. However, the intense 27 computational requirements severely limit their applicability to 28 coupled simulations of ice and bed. Our newest efforts use continuum 29 models of non-local granular fluidity to simulate essential behavior 30 on larger spatial and temporal scales. We show that the variability 31 observed in field borehole measurements can be explained by considering 32 the coupled dynamics of the ice-water-sediment system. From these 33 dynamics ice flow has the ability to rapidly reshape its bed, 34 providing additional feedbacks to ice contribution to sea level in 35 a changing climate.</blockquote> 36 37 <p>Slides and video below:</p> 38 39 <ul> 40 <li><a href="npub/esco2020-damsgaard.pdf">slides (pdf)</a></li> 41 </ul> 42 43 <center> 44 <video poster="video/damsgaard_esco2020.jpg" 45 controls preload="none" class="mediaframe"> 46 <source src="video/damsgaard_esco2020.webm" type="video/webm"> 47 <source src="video/damsgaard_esco2020.ogv" type="video/ogg"> 48 <source src="video/damsgaard_esco2020.mp4" type="video/mp4"> 49 <a href="video/damsgaard_esco2020.mp4">Link</a> 50 </video> 51 </center>