History of Great Salt Lake, Utah, USA: Since the termination of Lake Bonneville

Abstract

During the past half century or so diverse histories of Great Salt Lake have been written from differing perspectives and all of them have contributed ideas and essential data. The published literature, however, can be confusing and misleading. In this chapter, we review and provide context for a number of those publications. This chapter is intended as a summary of what is known, what is not known, and what cannot be known with precision about the history of the lake. Great Salt Lake is the largest hydrographically closed lake in the Bonneville basin of northwestern Utah. It responds to both short-term weather and long-term climate. In the Lake Bonneville/Great Salt Lake lacustrine system, the end of Lake Bonneville at 13,000 yr BP marks the beginning of Great Salt Lake. The much larger and deeper lakes of the Bonneville lake cycle responded to the pluvial climate of oxygen isotope stage 2, but the warmer, drier climate of oxygen isotope stage 1 led to rapid fluctuations within a relatively narrow, well-documented elevation range, 5 m above and 9 m below the historical mean elevation of ~1280 m. Two exceptional but short-lived rises of Great Salt Lake to elevations higher than 5 m above ~1280 m have been documented —one during the Gilbert episode, which peaked about 11,600 yr BP near an elevation of 1295 m, and one to about 1289 m sometime after about 11,000 yr BP. The historical Great Salt Lake hydrograph (the past 150 years) shows its labile behavior. Smooth-curve hydrographs based on estimates of lake level at time scales of decades, centuries, or millennia, such as those presented in previous publications, do not accurately portray the way lake level rises and falls, and a precise plot of post-Bonneville changes in level of Great Salt Lake would resemble the “jagged” historical record. The available sedimentary and geomorphic data are not conducive at this time to the production of a highly precise hydrograph, so we suggest that post-Bonneville lake-level history be portrayed, imprecisely but accurately, as confined generally between the elevation limits of 1285 and 1271 m, with an indication of the exceptional spikes in the lake level.