The Symposium on Snow in Motion was sponsored by the Mountain Snow and Avalanche Research Project of the Rocky Mountain Forest and Range Experiment Station, U.S. Department of Agriculture Forest Service, and the International Glaciological Society and was held at Colorado State University, Fort Collins, Colorado, U.S.A. from 12 to 17 August 1979. The Symposium was organized through two committees. The Organizing Committee consisted of Richard A. Sommerfeld (USDA Forest Service), M. Martinelli, Jr (USDA Forest Service), and Hilda Richardson (Secretary General, International Glaciological Society). This committee planned the detailed running of the Symposium. The scientific content was the responsibility of the Papers Committee, consisting of P. M. Föhn (Switzerland), J. W. Glen (representing the Editors of the Journal of Glaciology), T. E. Lang (U.S.A.), T. Nakamura (Japan), R. I. Perla (Canada), and U. Radok (Australia). This committee selected the programme from summaries submitted by a deadline date in October 1978 on the basis of scientific merit and relevance to the topics of the Symposium. These were listed as: I. Snowcover stability evaluation and avalanche prediction (A. Statistical approach, B. Physical approach, C. Casual-intuitive approach, D. Avalanche warnings and public education in avalanche awareness); II. Snow and avalanche mechanics (A. Theoretical considerations, B. Field and laboratory measurements, C. Modelling efforts, D. Interaction of avalanches with stationary objects); III. Avalanche zoning (A. As a technical problem, B. As a socio-political problem, C. Current zoning situations in various countries); IV. Wind transport and deposition in irregular terrain (A. Theory, B. Measurements, C. As a factor in avalanches, D. Application of control techniques). In addition to those papers selected for presentation in the main sessions, a number of papers were presented simultaneously in a poster session. The Papers Committee also invited four speakers to present invited papers on allied topics of interest to Symposium participants. The first and second circulars for the Symposium giving further details were published in Ice, No. 54, 1977 and Nos 56 and 57, 1978.

The International Glaciological Society agreed to publish the proceedings of this Symposium on the same conditions as for its own symposia, that the papers are received by a stated deadline and are then subjected to the same refereeing procedure as for papers submitted to the Journal of Glaciology. Papers presented in the poster sessions were treated in the same way as "Short notes" in regular issues, with a shorter maximum length than regular papers. This issue of the Journal contains those papers together with abstracts of papers presented at the Symposium but not published in full.

The papers in this issue are approximately in the order in which they were presented; the poster session papers are placed together at the end.

The Editors of the Journal acknowledge the help they received from members of the Organizing Committee and the Papers Committee in the handling of papers, including assistance with organizing the refereeing of papers.

This volume represents the last of a series of volumes of the Journal of Glaciology containing symposium proceedings. The two symposia with which the International Glaciological Society is associated in 1980 will be published as the first two volumes of a new series entitled Annals of Glaciology. Full details can be obtained from the Secretary General of the International Glaciological Society.