This short note describes the equipment and procedures we have developed to mount end caps on ice-core specimens. The system typically achieves end-plane parallelism within 0.5 μm/mm of specimen diameter (i.e. a total indicator run-out of 0.002 in for a 4.0 in diameter specimen). The essential elements of the system are a holder and an alignment fixture. The holder firmly grips the ice core about its circumference by the compression of two series of O–rings. The alignment fixture clamps the holder to align the ice core precisely with the end caps. To bond the ice to the end cap we form a layer of 0°C water on the end cap; the water freezes immediately upon contact with the ice and forms a strong intimate bond. To date, we have used this system to install phenolic end caps on 101.6 mm diameter cores and aluminum end caps on 76.2 mm diameter cores of saline ice. We obtained a somewhat better tolerance with the aluminum caps (0.33 μm/mm of end-cap diameter), due primarily to the geometric stability of that material under the prevailing conditions. These specimens have been successfully tested in uniaxial and triaxial compression, and we expect that with appropriate end caps the system will be suitable for preparing tension specimens as well.

On 19 and 20 August 1984, an ice-marginal lake drained through a subglacial tunnel beneath the ede of the Greenland ice sheet, discharging about 22.3 × 106 m3 of water in less than 19 h. The event, which may occur annually, modified ice-margin dynamics at the lake site and along a 3 km stretch of ice margin 11 km down-stream.

A Bailey bridge built on a permanent ice body at an altitude of 5580 m above mean sea-level has been carrying regular traffic of 7 tonne motor vehicles for over 2 years. The problems posed by the ice body, its behaviour under the load of the bridge and traffic, its summer and winter behaviour, and the problems posed in the construction and maintenance of the bridge are studied and discussed.

A model is proposed for determining the relative proportions of 16O and 18O in large ice sheets. Values calculated using this model are in agreement with published values for Antarctica and Greenland. It is intended to use the model for comparisons between the known ocean isotopie records and postulated ice-sheet masses during the last ice age.