Nature Notes

Vol. XI November 1933 No. 9

Annual Recession Measurements of the Glaciers of Mount Rainier

Annual recession measurements were made, as has been the custom for several years, on the Emmons, Nisqually, South Tahoma, Carbon and Paradise Glaciers during the month of September. The first four named are alpine or valley glaciers which are known to have a downward flow and are thus know locally as "living" glaciers. The Paradise Glacier is a cliff glacier or glacieret that has very little, if any, downward movement and is therefore known locally as a "dead" ice field. The Emmons and Nisqually have their origin in the neve field at Mt. Rainier's summit while the Carbon and So. Tahoma originate in great cirques or catch basins about the 10,000 foot elevation. The glaciers measured were selected because of these facts, because of their position on the flanks of "the mountain" and because of other minor factors that may have a bearing upon glacial recession here. These figures then may be considered as indicative of the recession of all glaciers of Mt. Rainier.

These recession figures from Mt. Rainier Nat'l Park are of particular interest in as much as this national park possesses the largest glacial system radiating from a single peak in continental United States. There are 28 named glaciers aggregating some 45 to 50 square miles of ice.

Snout or terminus of Emmons Glacier in 1930

EMMONS GLACIER: (Largest in continental United States).

On Sept. 22nd, 1930 a metal marker was placed in a fissure on top of a large boulder on the south side of the Emmons Glacier near its terminus and a line bearing N. 30 degrees West was established. This glacier is very difficult to measure with any degree of accuracy due to its irregular and wide snout. The point from which the main stream emerges is considered the terminus of the glaciers in the case of recession measurements. This is to establish a definite point upon the usually irregular snouts from which to measure in future years. In the case of the Emmons the recession is tabulated by measuring from a point on the established line to the place from which the main stream emerges.

1930- Point, backsite and line established.
1930-1931 . . . . . recession of 142 feet.*
1931-1932 . . . . . recession of 2-1/2 feet.**
1932-1933 . . . . . recession of 48-1/2 feet.

* The great recession figure noted in this case was due to the fact that the ice above the stream had melted back in a deep and narrow cleft or horseshoe. This was brought about probably by a more rapid downward flow at the surface of the ice, causing it to shove out in the form of a lip and then break off under its own weight. Lobes of ice flanked this narrow cleft - the ends of these lobes being about 95 feet from the line of site instead of 142.

** In October, 1932, it was found that the main stream had changed its course beneath the ice and was emerging from a different place much nearer the line of site than the point on the ice that was farthest removed from the established line. The point of issuance of the main stream, then, was but 2-1/2 feet farther back than the point of issuance of the main stream in 1931. The farthest ice from the line of site was 161 feet, which would have exhibited a recession of 19 feet had we been measuring from that point. These irregularities will occur in the future, but the average recession over a period of years will exhibit a true perspective of the rate of backward movement of this glacier. At the end of 1933 the Emmons presented no great difficulty.

CARBON GLACIER: Lowest perpetual ice in continental United States. Elevation, about 4,000 feet.

Markers were placed at different points both in 1930 and in 1931, but each year they were destroyed or washed out in some manner. In October, 1932, a marker was placed in a position that was retained, and so this year we have the first recession figure on this glacier.

1932- Marker from which recession measurements will be made in the future established.
1932-1933 . . . . . recession, of 12 feet.

NISQUALLY GLACIER: Most accessible glacier in the United States. Easy trail from highway to snout about one-third of a mile distant. Annual measurements have been made since 1918 and previous to that time reliable historical data furnishes an idea of the position of the Nisqually's snout since 1857.


1857-1885 . . . 760 feet.
1925-1926 . . . 86 feet.
1885-1892 . . . 140 feet.
1926-1927 . . . 43 feet.
1892-1918 . . . 1310 feet.
1927-1928 . . . 89 feet.
1918-1919 . . . 59 feet.
1928-1929 . . . 52 feet.
1919-1920 . . . 46 feet.
1929-1930 . . . 118 feet.
1920-1921 . . . 106 feet.
1930-1931 . . . 49 feet.
1921-1922 . . . 67 feet.
1931-1932 . . . 50 feet.
1922-1923 . . . 44 feet.
1932-1933 . . . 44 feet.
1923-1924 . . . 83 feet.
1933-1934 . . . ? feet.
1924-1925 . . . 73 feet.

(Note: the sketch serving as the cover of this issue of Nature Notes is of the snout of the Nisqually Glacier as it appears today.)

SOUTH TAHOMA GLACIER: Recession studies were begun on this glacier in October, 1931 - at which time a large rock on the moraine immediately in front of the glacier was marked. Recession data follows:

1931- Point from which future recession measurements will be made was marked.
1931-1932 . . . . . recession of 27 feet.
1932-1933 . . . . . recession of 13 feet.

Paradise Glacier and Ice Caves in 1930

PARADISE GLACIER: A cliff or "dead" glacier famous for its ice caves. As the front of this glacier is very broad, three points were established in 1932, and measurements will be made from all three each year in order to get a better idea of the recession of this ice field. In the past it is quite evident that the Paradise has shrunk a great deal in size. However, due probably to the heavy snow of the past two winters, the Paradise has receeded little recently. Last winter's snow did not entirely melt away and, in fact, one of our points was still obscured from view by several feet of snow and was eliminated from the tabulation thereby. It is possible that the ice at that point receeded not at all and probably extended itself beyond the point of the previous year. Tabulations follow:

YearDist. from ice.Recession.

1932A-13 feet
B-38 feet
C-45 feet
Points est.
in this

1933A-covered with snow
B-43 feet
C-52 feet
5 feet.
7 feet.

NOTE: If these recession figures cause you worry lest the glaciers of Mt. Rainier - one of the principal features of interest here - disappear before you get another chance to see this park, just let it pass. Figure it out for yourself. The Nisqually, for instance, is about five miles long, and at the present average rate of recession, the Nisqually will have the status of a glacier at least for about 5,000 years.

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