Context: Ice shelf dynamics and climate change

Antarctica's ice shelves act as buttresses that slow the flow of ice from the interior to the sea, and their collapse or thinning can accelerate sea-level rise. The video highlights how West Antarctica is experiencing significant changes, with cracks forming and propagating in key shelves such as Thwaites and Pine Island. This dynamic is increasingly driven by an warming ocean and climate shifts that undermine the shelves’ stabilizing role.

"Ice shelves are very important on the global scale. They are the floating parts that surrounds the margins of the continent. They hold back ice from the interior of the Antarctic continent." - Oliver Marsh

Fieldwork on the Brunt Ice Shelf

The Brunt Ice Shelf hosts active cracks and rapid surface movement, including full-thickness rifts known as “rifts” that have produced large icebergs in recent years. The Halley Research Station sits nearby, and researchers collect a diverse array of data—from satellite imagery to on-the-ground radar—to monitor crack growth and subsurface conditions.

"The ocean is warming and a lot of the ice shelves are melting and thinning and that is reducing their buttressing power." - Oliver Marsh

Rift Tip Project and Halloween Rack

Central to the project is understanding when and how ice fractures to form big icebergs. Halloween Rack formed rapidly, turning from a vast open crack to a hairline fracture, underscoring gaps in current understanding and the need for integrated observation and modeling.

"The Rift Tip project is about trying to understand the rate and timing of why ice fractures, and why we get these large icebergs produced from ice shelves." - Emma Pearce

"We need to understand what's happening at both small scales and large scales to link crack growth with iceberg production." - Emma Pearce

From Cores to Cracks: Laboratory and Microstructural Studies

Researchers bring ice cores back to laboratories for detailed analysis. They study crystal orientation, grain size, and melt layers to determine how microstructure influences fracture toughness. The team uses polarized light microscopy on thin ice sections to reveal crystal orientations and stress histories, and conducts controlled fracture tests to measure how depth and microstructure affect strength.

"What controls the strength of a material is the things that are within it, so many things that are crystalline essentially have a grain size, and a grain size is a primary control on how things break." - Tom Mitchell

Modeling Calving and Policy Relevance

Laboratory results feed into models that simulate crack growth and calving events. The researchers develop two-dimensional representations of stress around cracks to forecast when new ice fronts will appear and how quickly calving might occur. They emphasize the goal of producing predictive tools that can inform policymakers about potential sea-level rises and guide climate adaptation strategies.

"We can run the model forward in a kind of predictive way and find out what the future behavior of this particular ice shelf will be." - Oliver Marsh

"We need to give policymakers the information that they need." - Oliver Marsh

Categories

Company

Stay up to date

# Halley-Research-Station

Why scientists are worried about Antarctica’s giant ice cracks

Join curiosity curated 🔬