Kristina M. Pascher (a,b), Christopher J. Hollis (a), Robert M. McKay (b) & Giuseppe Cortese (a)
(a) GNS Science, PO Box 30368, Lower Hutt 5040, New Zealand. E-mail: K.Pascher@gns.cri.nz
(b) Victoria University Wellington, Antarctic Research Centre, PO Box 600, Wellington 6140, New Zealand.