3 Feb 2011

Platelet Sea Ice

From Our Changing World, 9:06 pm on 3 February 2011

Pat Langhorn looking at platelet ice crystals under polarised lightPat Langhorne is a physicist at the University of Otago, and her research focuses on crystals that form within Antarctic sea ice, in particular platelet ice that forms on the underside of sea ice in areas close to large ice shelves which act to supercool seawater. She measures the size and orientation of the platelet ice crystals on ice cores drilled out of the sea ice, by looking at them under polarised light, which can help determine the conditions under which the ice formed. She has organised several trips to Antarctic, when research teams over-wintered to investigate both oceanographic and ice conditions from the time sea ice began to form in late autumn, right through winter until the ice broke up the following spring.

Stefan Jendersie holding a portion of a core of sea ice


Pat Langhorne (above right) looks at platelet ice crystals that are coloured by being viewed under polarised light, and Stefan Jendersie (left) holds part of a sea ice core
(images: J. Dodgshun)

Alison Ballance visits Pat and student Stefan Jendersie at Camp Haskell, and is invited out of the Antarctic warmth into a very cold walk-in freezer where the research is carried out.

Veronika Meduna spoke with Pat Langhorne and the overwintering team prior to their departure to the ice in 2009.