File:Great Salt Lake (MODIS).jpg

English: The Great Salt Lake, located in the state Utah, is the largest saline lake in North America. Both the lake itself and the nearby wetlands form a critical keystone ecosystem that has profound effects on regional biodiversity, human welfare and the economy. It is also vital to the health of the wider ecosystem, increasing annual snowfall in nearby mountains by 5-10 percent. As part of the Pacific Flyway, an estimated 10 million migratory birds use the wetlands and lake each year, with about 350 different species of bird dependent on the Great Salt Lake environs.

The water levels in the lake are, to some degree, dependent on rainfall and the accumulation of winter snowpack in the surrounding mountains, with water levels rising in wet years and falling in dry ones. After years of drought, overuse of the lake’s water resources, and diversion of streams that feed the lake, the Great Salt Lake has shrunk dramatically, becoming a critically endangered resource.

According to the Utah Department of Natural Resources, the average daily value of Great Salt Lake hit a new record low in November 2022, when it dropped to 4188.5 feet as measured at the South Arm Causeway gauge location. Records have been kept since 1847. After a record snowpack accumulated in the winter of 2022-2023, the water level in Great Salt Lake rose an astounding 5.5 feet by July 2023—a wonderful but very temporary respite for the steadily shrinking lake.

In January 2023, the Brigham Young University College of Life Sciences, Plant and Wildlife Sciences published a detailed brief on their website about the imminent danger posed by the loss of the Great Salt Lake. Titled “Emergency measures needed to rescue Great Salt Lake from ongoing collapse”, it explains that “Without a dramatic increase in water flow to the lake in 2023 and 2024, its disappearance could cause immense damage to Utah’s public health, environment, and economy. This briefing provides background and recommends emergency measures.” The brief also outlines in detail the reasons for the decline as well as strategies that can be implemented. The increased water level from the melt of the record snowpack is very welcome, but no more than a temporary “drop in the bucket” for the overall health of the lake.

On August 4, 2023, the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Terra satellite acquired a true-color image of the Great Salt Lake. Although the lake is near peak water levels for the year, it has not filled much of the dry lakebed that surrounds the dual-toned waters. In fact, this image does not appear extremely different than that acquired by MODIS on Terra on June 15, 2022, only months before the Great Salt Lake reached its all-time low level. To view the image captured on that date, click here.