Ice shelves

It’s not you, it’s me(lange): ice shelf break-up triggered by mélange and sea-ice loss

Jenny Arthur May 21, 2021

Fig. 1. Mélange (a mixture of calved icebergs, sea ice and material) in Porpoise Bay, East Antarctica, located ~100 km east of Voyeykov Ice Shelf [Credit: NASA Operation IceBridge].

Between March and May 2007, a total of ~2,445 km2 (equivalent to over 17 football pitches) of ice mélange (a mixture of sea-ice types, icebergs and snow) and part of Voyeykov Ice Shelf in East Antarctica rapidly broke up. Observations of the timing and triggers of such events are relatively rare in East Antarctica, compared to ice shelves on the Antarctic Peninsula. Recent work highlights the impo ...[Read More]

How small changes can make a big difference: tipping points in Antarctica

Ronja Reese & Dave Chandler November 13, 2020

As Antarctica’s mass loss increases, the threat of crossing tipping points both in the ice sheet and the surrounding Southern Ocean is increasing. But what actually is a tipping point? Have tipping points already been crossed in the past? And what might the future hold? What do we mean by a “tipping point”? Scientifically speaking, a tipping point is generally understood to be a threshold that, on ...[Read More]

Image of the Week – Kicking the ice’s butt(ressing)

Ronja Reese May 10, 2019

Changes in the ice shelves surrounding the Antarctic continent are responsible for most of its current contribution to sea-level rise. Although they are already afloat and do not contribute to sea level directly, ice shelves play a key role through the buttressing effect. But which ice shelf regions are most important for this? The role of ice-shelf buttressing In architecture, the term “buttress” ...[Read More]

Image of the Week – (Un)boxing the melting under the ice shelves

Ronja Reese November 30, 2018

Figure 1: Melting underneath Antarctic ice shelves as modelled with the Potsdam Ice-shelf Cavity mOdel (PICO) for present-day ice geometries and ocean conditions. Extending a simple ocean box model approach (Olbers and Hellmer, 2010), it efficiently calculates the wide range of melting in Antarctica [Credit: adapted from Fig. 5 of Reese et al. (2018)]

The Antarctic ice sheet stores a large amount of water that could potentially add to sea level rise in a warming world (see this post and this post). It is currently losing ice, and the ice loss has been accelerating in the past decades. All this is linked to the melting of ice – not at the surface but at the base, underneath the so-called ice shelves which form the continuation of the Antarctic i ...[Read More]