“The Salton Sea is ghastly,” William T. Vollmann wrote in his book “Imperial.” “Come closer, and a metallic taste sometimes alights upon your stinging lips. Stay awhile, and you might win a sore throat, an aching compression of the chest as if from smog, or honest nausea.”

For decades now, the sea, created by accident in 1905 and fed in part by agricultural runoff, has been shrinking, while the salinity continues to rise. During heat waves, like the recent one that has baked the region, the oxygen content in the water suddenly drops, killing thousands, sometimes even millions, of fish. Almost eight million tilapia died on a single summer day in 1999.

Image Credit... The New York Times

The Salton Sea is less than 60 feet at its deepest point now, according to Andrew Schlange, general manager of the Salton Sea Authority. He said the sulfurous odor escapes from the lake a few times a year, usually after a storm stirs up the organic matter, like dead fish, decomposing at the bottom.

In the past, though, the smell has been confined to the Coachella Valley, where the lake is. But Mr. Schlange called a disturbance that blew through the area on Sunday night “maybe the perfect storm.”

“As shallow as the sea is, it got stirred up,” Mr. Schlange said. “With the wind blowing from the southeast, we probably got a very big blast of this odor coming up.”

If the water level in the lake continues to fall, however, Mr. Schlange said he would expect the sulfur smell to emanate more often.