Wednesday, March 13, 2024

Death Valley Ephemeral Lake

Death Valley is the driest place in North America, with some areas receiving less than two inches of rain per year, and is the location of the highest temperature (134 °F on July 10, 1913) ever recorded in the United States. The valley is not dead, it is a below-sea-level basin, surrounded by towering peaks that are often frosted with winter snow. Rare rainstorms bring vast fields of wildflowers. Lush oases harbor tiny fish and serve as a refuge for wildlife and human life.

Usually Death Valley visitors see a vast salt flat at Badwater Basin. However heavy rain from Hurricane Hillary in August 2023 brought 2.2 inches if rain that filled the valley floor with a vast, shallow lake. At its largest, it was about 7 miles long, 4 miles wide, and two feet deep. Imagine only 2.2 inches of rain doing that!

By late January it had shrunk to about half that size, and was inches deep. Then an atmospheric river brought another 1.5 inches in early February, 2024 and after the atmospheric river moved through, the lake continue to expand as water drained into the basin from the Amargosa River, which feeds the basin from the south.  The Amargosa is usually an intermittent river was observed to be flowing by park rangers.

Badwater Basin is endorheic, meaning that water flows into but not out of it. Typically, evaporation far outpaces inputs from rain and the Amargosa, rendering the lake ephemeral. But in the past six months, the unusual atmospheric rivers have changed the equation. As of mid February, the lake is 1 foot deep in places, and it is uncertain how long it will last. Past appearances of the lake are rare- appearing in 2005 and 2015 and none on record have lasted as long as this one.

The satellite image below is from NASA Earth Observatory images by Wanmei Liang, using Landsat data from the U.S. Geological Survey. Photo by K. Skilling/National Park Service.


No comments:

Post a Comment