Sir,

This notice is submitted in order to place in a permanent, accessible form the record of an ice flow experiment whose completion is not expected until many years hence when the present generation of glaciologists will have passed away. Site of this experiment is the Blue Glacier on the northern flanks of Mt. Olympus, located on the Olympic Peninsula of western Washington State, U.S.A. (lat. 47° 48′ N., long. 123° 42′ W.).

On 9–10 September 1963, 32 markers were placed on the firn surface of the two Blue Glacier accumulation basins. Details of the marker construction and placement are shown in Figure 1. Their locations are shown on the sketch map of the accumulation zone of Blue Glacier in Figure 2. The markers are numbered 1 through 19 (s = 37 cm.), and 21 through 33 (s = 56 cm.). Marker No. 20 (s = 37 cm.) has been placed in the Olympic National Park museum (U.S. National Park Service) in Port Angeles, Washington.

Fig. 1. Blue Glacie long-term ice flow marker. See text for further details

Fig. 2. Location of 32 long-term ice flow markers in the Blue Glacier accumulation zone. Contour interval is 25 m. This topographic sketch map is derived from American Geographical Society Special Publication No. 34, “Nine glacier maps: northwestern North America”, Sheet No. 2, Blue Glacier

Marker construction material is stainless steel strip of cross-section 50 mm. × 2.8 mm.

. Each strip is twisted times and the ends are joined to form an equilateral triangle. This configuration was chosen to provide maximum stability of position once incorporated in the ice, and as an unusual shape which would attract an observer’s eye when the markers reappear.

The markers are all in a zone of heavy annual accumulation where they will rapidly become buried in firn, and eventually in glacier ice. Their reappearance on the lower part of the glacier years hence is expected to yield valuable information on flow lines and velocities deep in an active glacier. It is hoped that future glaciologists will be encouraged by this present notice to recover these markers and identify the flow lines.

Copies of this notice are being filed with the National Park Service and with the University of Washington archives, together with other pertinent data which include a topographic map showing the 1963 marker sites and the compass bearings from these sites to fixed reference points.

25 September 1963