Geological Survey Professional Paper 387-A Botanical Evidence of the Modern History of Nisqually Glacier Washington

A common problem in hydrology is that of determining where modern water-supply data fit into the long-term pattern of fluctuating water supplies. Streamfiow and other water records are too short a base from which to extrapolate most long-range water-development plans. Therefore, water-resources investigators have sought, from time to time, to reconstruct past climatic trends by interpreting the physical evidence left by modern hydrologic events.

This study of the recent moraines of Nisqually Glacier, Mount Rainier, Wash., is one of the efforts to reconstruct past climatic trends. The hypothesis is simple: Glaciers advance and retreat in a manner somehow related to climate; therefore, if something is known of a glacier's movement in the past, some kind of crude inferences about the climate existing at the time of movement may be drawn. A larger study, of which the study of Nisqually Glacier is a part, is concerned with dating the terminal positions of several glaciers on Mount Rainier at several times in recent history when points of maximum advance were reached. Furthermore, because the present study is based on the ages of trees adjacent to the glaciers, only glacial advances during the last 1,000 years or less are being investigated. This report is concerned primarily with Nisqually Glacier but includes a brief discussion of a reconnaissance study of moraines formed by Emmons and Tahoma Glaciers. It is the first report of a series on the broader study.

Acknowledgment is made for the great assistance offered by the staff of Mount Rainier National Park, especially by V. R. Bender, chief naturalist. The writers benefited from discussions in the field and office with Arthur Johnson, D. R. Crandell, R. D. Miller, and D. R. Mullineaux of the U.S. Geological Survey. Arthur Johnson first interested the authors in the study, and he kindly compiled a planetable map of part of Nisqually Glacier terminal moraine especially for this report. Ethel W. Coffay of the U.S. Geological Survey provided considerable help in the study of core samples.