Surface Structures in Snow

Observations on smalland large-scale snow surface structures were made during overs now traverse operations in West Antarctica from 1958 to 1960, and during the winter of 1959 at Byrd Station. The strucutres are illustrated and described; their formation is discussed in relation to the shape and size of the individual crystals, the surface temperature, wind, and the interaction of these parameters. Snow surface structures are classified genetically into two major groups: Depositional and Erosional. Depositional structures include drift forms and fosses deposited around obstructions, current ripple marks, and barchanoids (barchan-like snow features). The erosional structures include several forms of sastrugi, irregular patterns, pits, footprints (human and canine), and other forms. The study reveals that footprints, impressions of boots, and other structures have a better potential of being preserved than do the original smooth and soft surfaces. This depends largely on'the micro meteorological parameters which provide subsequent consolidation and densification of the covering snow particles. 'By understanding the physical characteristics and the mechanisms involved in the formation of these s'urface structures, their interaction with their environmental parameters, and comparing them with corresponding factors affecting other sedimentary deposits, it will be possible to reconstruct certain ecologic conditions prevalent at the time of deposition.