How do ice shelves break? Assessing the mechanisms behind ice shelf rifting in Antarctica
The next UCL WiES seminar will be by Emma Pearce, an Ice Fracture Geophysicist from the British Antarctic Survey.
Wednesday 29th October in KLB 127 1-2pm, followed by tea and coffee.
How do ice shelves break? Assessing the mechanisms behind ice shelf rifting in Antarctica
29 Oct 2025, 13:00 – 14:00
How do ice shelves break? Assessing the mechanisms behind ice shelf rifting in Antarctica with Emma Pearce.
Fracture-induced instability of marine ice shelves remains one of the largest uncertainties in projecting sea-level rise, with direct implications for global flood mitigation planning. Although ice shelves are known to fracture once critical stress thresholds are exceeded, the precise mechanisms controlling fracture timing, propagation rate, and path orientation remain poorly understood, particularly on ice shelves composed of varying ice types, such as the Brunt Ice Shelf in Antarctica.
On the Brunt Ice Shelf, seismic and satellite observations indicate that rift trajectories often diverge from stress-predicted paths, preferentially skirting around thicker blocks of continental ice and cutting through thinner, marine ice sections. However, these observations have previously lacked a direct mechanical underpinning.
To address this gap, in 2024 we drilled four boreholes at the tip of an actively propagating rift, (Halloween Crack), recovering ice cores from both marine and continental ice. Concurrently, we deployed a dense seismic network consisting of 64 stations surrounding the rift and borehole locations. The recovered ice cores underwent laboratory-based three-point bending fracture mechanics tests to quantify fracture toughness and related physical properties of each ice type. Simultaneously, our seismic array captured icequake events associated with rift propagation, allowing localisation of fracture deformation and identification of differing fracture mechanisms across varying ice types.
By integrating lab-derived mechanical metrics with detailed seismic observations, we establish links between ice type, mechanical properties, and rift propagation dynamics.
The event is open to all ES staff and students, please register to attend!
Emma will be at UCL from 11am so if you would like to meet her before the seminar please let us know!
