Nature Notes

Vol. VI December, 19228 Winter Season No. 9


On November 4, 1928 Asst. Chief Ranger Macy and the Naturalist measured the recession of the Nisqually Glacier and found that the past year witnessed a recession of eight nine feet. This is the greatest recession recorded since 1921 when a recession of 106 feet was tabulated.

The glaciers of Mount Rainier, like all glaciers throughout the world, are gradually receeding for the annual replentishment by the heavy snowfall on the Mountain's flanks is not sufficient to make up for the melting at the terminus. Glaciers are all reminders of the ice age of many years ago and are remnants of either great ice cap itself of of local glaciation such as occurred in the region of the Rocky Mountain National Park in Colorado. Mount Rainier's glaciers once merged with the lobe or finger of the ice cap that pushed south along the Cascades from its southern terminus. When the ice cap receeded Rainier's glaciers remained, fed by the extremely heavy snowfall on the sides of the Mountain. These, too, gradually worked backward as the years went by until in 1885, according to F.M. Matthes who has made extensive geological studies of the Mountain, the terminus of the Nisqually occupied the point where the Nisqually Glacier Bridge now stands. Today it is over a half mile removed from that point.

From 1857 to 1924 it receeded 2615 feet. During the past four years it has melted back eighty nine, forty three, eighty six and seventy three feet respectively. However, if you are interested in glaciers don't cancel your plans for a visit to the Mountain. Mt. Rainier boasts of the greatest glacial system radiating from a single peak in the United States. There are 28 glaciers in all and several of them are over five miles long.


Do you, who have seen the streams of the Park during the summer, remember the milky consistency of the water? You were told, if you made inquiry as to the cause of this, that such coloration is due to the presence of "glacial four" or powdered rock that is the result of the grinding action of the glaciers as they move slowly down the mountainside. Countless numbers of these minute particles of rock give the streams that milky color in the summertime.

At present the streams are practically clear. The downward movement of the glaciers practically ceases during the winter months and thanks to the heavy snow are enjoying a period of partial recuperation from the melting that took place during the warm summer months. In spite of the fact that the glaciers on the Mountain are gradually moving down the melting at the terminus more than offsets this movement so that actually they are receeding (see above). During the summer the downward movement is very noticeable because of the glacial flour that results from the grinding action of the ice as it passes over its bed and widens its channel.

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