Title: Tide-sediment interactions beneath Antarctica

 

Abstract: The majority of ice in Antarctica reaches the ocean through fast-flowing ice streams, which slide over a layer of water-saturated subglacial sediment (till). Understanding the dynamics of the sediment is therefore key to understanding the behaviour of Antarctic glaciers. In this talk, I will discuss two ways in which tidal processes shed light on the rheology of till.  First, I will describe how the morphology of tidally-modulated ribbed landforms observed close Thwaites Glacier, West Antarctica, constrain sediment fluxes and ice retreat rates in the recent past. I will then switch to the microscale, and using ideas from granular mechanics, discuss the tidally-driven grain-water interactions in the till, and how this explains velocity patterns in present-day West Antarctic glaciers.

 

About the series: Lecture portion of EAPS graduate-level class in geophysics, 12.571. All members of the MIT community are welcome to join for presentations by guest speakers, held approximately every two weeks during the term.  For more info or Zoom password, contact jkastorf@mit.edu.