GRASSHOPPER GLACIER OF MONTANA — GURNEY 311 



During this Recent period, in which we now live and to which the term 

 "little ice age" has been applied, there have in turn been climatic fluc- 

 tuations. In the Middle Ages comparatively mild conditions existed, 

 but around A. D. 1600, as shown by buried villages in Iceland and 

 evidence in Scandinavia and elsewhere, there began a moderate but 

 definite expansion of glaciers. In recent decades there has been a tend- 

 ency for many, but not all, glaciers to recede again. "The present re- 

 cession of glaciers, which began in the 1850's and which since 1920 

 has proceeded at an accelerated rate, is merely the latest episode in the 

 'little ice age.' It may mark the end, or it may not" (Matthes, 1942b) . 

 Since Dr. Matthes' death it has become increasingly evident that the 

 recession of many glaciers is decreasing and some are advancing again 

 (Baird et al., 1951). About 7 years ago a minor climatic change of 

 increased precipitation and lower temperature began to occur in 

 Glacier National Park. Frequently, some years are required for minor 

 changes in climate to have noticeable results at the foot of a glacier, so 

 slowly are effects transmitted for the length of a glacier. 



As examples of glacial decline, the Easton Glacier on Mount Baker, 

 Wash., receded 4,900 feet between 1908 and 1936, and some small 

 glaciers on the Cascade Range in Oregon have entirely disappeared 

 in the past 25 years. The recession of the Nisqually Glacier on Mount 

 Rainier has been conspicuous and has been carefully recorded, amount- 

 ing to 4,708 feet from 1857 to 1951, an average of about 5,000 feet per 

 year. There is a practical importance to the measurements made on 

 the Nisqually Glacier because water originating there contributes 

 to the municipal water supply of Tacoma, Wash. If the glacier even- 

 tually disappears or becomes much smaller than at present, supple- 

 mentary sources may be required. 



Changes in the size and appearance of Grasshopper Glacier have 

 been observed by Dr. J. R. Parker, who has given me an account of 

 five separate trips there. He first visited it with Dr. R. A. Cooley in 

 July 1918, and they found the glacier much as shown in plate 1. He 

 judged the exposed face toward the west end to be 50 to 75 feet from 

 the ground to the top layer of ice and snow. He cut individual grass- 

 hoppers from the top layer at depths of 1 to 12 inches. Grasshoppers 

 also were found in lower layers where exposed at the foot of the glacier, 

 and dried grasshopper remains were found under many small flat 

 rocks which occurred on the higher slopes adjoining the snow and 

 ice field of the glacier. Dr. Parker reasoned that this last condition 

 indicated that the glacier at sometime had covered a considerably 

 larger area and had contained grasshoppers there before it had 

 receded. He made other trips in 1922, and in either 1925 or 1926, and 

 found the general appearance to be the same on each occasion. During 

 a 1931 visit he estimated that the face was 25 feet lower. When there 



236639—53 21 



