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PRESENTATION INFO


'The Movement of Brines in the Great Salt Lake'
J Wallace Gwynn (g9434@msn.com), J. Wallace Gwynn Consulting LLC



Brine movements in Great Salt Lake go beyond the obvious ups and downs of the lake, which are governed by the balance between total inflow and evaporation, or even the wind tides or seiches that accompany strong winds. Large-scale, generally counterclockwise currents circulate slowly in both the north and south arms of the lake. Though south-to-north flows through the bridged openings in the railroad causeway are observed, the return flow of north-to-south brine that occurs at depth, within the same opening, is hidden from view. The existence or absence of this return flow is dependent upon the widely variable head differential between the north and south arms, and their respective but changing brine densities. When return flow from the north arm does enter the south arm, it first must flow into a closed basin in the northwest portion of that arm. Once the closed basin is filled, it spills over an eastern topographic low and then southerly into the depths of the main body of the south arm. Without this return flow, the south arm of the lake will decline in salinity. Tongues of south-arm brine extend through bridged openings into both Farmington and Bear River Bays. The distance that the tongues extend into the bays from the south arm is dependent upon the head differentials and the relative brine densities. During the 1980s flooding, a tongue of south-arm brine was found extending up the Weber River, beneath the flowing river water.