Why ice shelves matter

Over the last decade, the Greenland and Antarctic ice sheets contribute about 0.8 mm per year to sea level rise (Hanna et al., 2013), which is almost one third of the annual global signal. Projections of mass loss for the next 100 to 200 years point to a significantly more dominant contribution of both ice sheets in the global sea-level budget. Thinning Antarctic ice shelves and the corresponding decrease in the restraint experienced by inland ice flow are recognized as major drivers of current Antarctic ice loss (IPCC, 2013). This ice-shelf change is particularly pronounced in West Antarctica, in response to increased oceanic heat transport beneath its floating ice shelf and resulting feedbacks, but evidence from around Antarctica confirms that the effect is not geographically limited. Ice shelves are crucial gatekeepers of Antarctic ice sheet flow, because they restrain ice flow as they are often laterally constrained by embayments or locally grounded on rigid obstacles in the bathymetry. Ice-shelf thinning causes an instantaneous acceleration and a retreat of the grounding-line, hence a rise in sea level.

The @TweetinIceShelf

The Roi Baudouin Ice Shelf (RBIS) is a 'small' (the size of Belgium, actually) ice shelf in Dronning Maud Land, Antarctica, at proximity of the Princess Elisabeth station (Belgium). Since 2008, the Université Libre de Bruxelles has been extremely active in exploring, measuring and monitoring the ice shelf (see publications) using active geophysics (radar, GNSS) and ice core drilling. Collaborating projects include BENEMELT.

Contrary to larger or more 'active' ice shelves, RBIS is rather accessible, even across the grounding line (limit between the grounded ice sheet and the floating ice shelf), which allowed to actually undertake precise measurements. The @TweetinIceShelf started as an outreach project from the 10km ULB run, but the science that it encompasses is based on projects by BELSPO (BELISSIMA, IceCon, MIMO), FNRS (IDYRA, MEDRISM), InBev-Baillet Latour (Be:WISE).