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Scott Polar Research Institute - Physical Sciences Seminar

Seminars on polar physical sciences are held at the Scott Polar Research Institute during the Michaelmas, Lent and Easter terms. The seminars typically take place on Wednesdays between 16.30 and 17.30 and are held in the main lecture room, which can be accessed via the polar museum. Doors are open to public and all are welcome.

View the archive of previous seminars.

# Wednesday 18th October 2017, 4.30pm - Mr Michael Cooper
What lies beneath: a radio-glaciological study of Greenland.
Venue: Scott Polar Research Institute, main lecture theatre

Despite several decades of satellite and airborne geophysical surveys over the Greenland Ice Sheet (GrIS) there is still much that we do not know about the properties of the bedrock that lie beneath the ice, and to what extent basal characteristics influence ice dynamics. Whilst surveys were initially conducted to better constrain future sea-level rise contribution from glaciological modelling, radio-echo sounding (RES) has the potential to reveal basal characteristics relevant to both contemporary and palaeo-ice dynamics, and information regarding geology, landscape alteration and genesis.

This talk will detail several examples of this ‘extra’ information to be gleaned from RES conducted as part of my PhD research, as well as some future avenues for investigation.

# Wednesday 15th November 2017, 4.30pm - Dr Suzanne Bevan
Remote sensing of melt and fracture on Larsen C ice shelf, Antarctica
Venue: Scott Polar Research Institute, main lecture theatre

Surface meltwater ponding has been implicated in the recent break-up of ice shelves along the Antarctic Peninsula. I will present some observations of ponds on Larsen C ice shelf and show how they coincide with troughs in the surface mapped using synthetic aperture radar (SAR) interferometry. For ponds to form, the ice shelf surface needs to have undergone sufficient melt/refreeze cycles to densify the ice to the point at which it is impermeable to continued melt. It is relatively straightforward to spot surface ponding in optical satellite imagery but detecting liquid water within an unsaturated snow pack requires observations in the microwave. I will show how QuikSCAT and, recently available, enhanced resolution ASCAT radar scatterometry data reveals patterns and trends in melt on the ice shelf from 1999-2017.
Finally, I will show how we used interferometry and the Sentinel 1 SAR data to monitor the progression of the rift which caused the recent calving of the 5,800 km2 ice berg from Larsen C.

# Wednesday 29th November 2017, 4.30pm - Dr Adam Booth
Geophysical observations on Larsen C Ice Shelf: characterising stability after Iceberg A68
Venue: Scott Polar Research Institute, main lecture theatre

The floating ice shelves that fringe much of the Antarctic continent have become prominent in predictive models of sea-level rise. Once considered to be ‘passive players’ within the glaciological system, they are now considered to be significant buffers to ice loss from terrestrial Antarctic glaciers. The removal of that buffer via shelf collapse exacerbates the transit of terrestrial ice to the oceans. Larsen C Ice Shelf, on the Antarctic Peninsula, has been of particular interest in recent years following observations of i) a loss of shallow firn in its upstream reaches, and ii) a sporadically-propagating rift parallel to its calving front. Both of these mechanisms are invoked in ice shelf collapse, although it is the latter that is currently foremost in the public eye.

On 12th July 2017, Larsen C calved one of the largest icebergs ever observed. Iceberg A68 represents 12% of the Larsen C area although, as colossal as its vital statistics are, the calving event has more significance as a portent of shelf instability. The collapse of Larsen B in 2002, for example, was preceded in 1995 by a similar calving event; and followed thereafter by an acceleration of its tributary glaciers. However, observational control of the immediate aftermath of iceberg calving is sparse, hence the models with which ice shelf (in)stability is predicted are unconstrained.

In this talk, I will review the physical constraints that we (Leeds, Swansea and Aberystwyth Universities) have accrued for characterising stability-critical points around Larsen C. This will include an introduction to a new NERC Urgency Grant that seeks to quantify the mechanical properties of the ice shelf in the short-term aftermath of the A68 calving event.

# Thursday 8th March 2018, 4.15pm - Walter Immerzeel
This talk is part of the Department of Geography Seminar Series
Recent advances in understanding climate, glacier and river dynamics in high mountain Asia
Venue: Small Lecture Theatre, Department of Geography, Downing Site

Abstract not available