Angelic Anderson crouched down and ran her fingertips throughout a big white mound that rose a number of inches from the floor of the bone-dry lakebed. As a park ranger on the Great Salt Lake State Park in northern Utah, she’s accustomed to seeing the large lake’s waterline recede, particularly throughout dry months when there’s little to no rainfall. However, over the course of the previous few winters, she and different rangers have seen one thing unusual taking place alongside the lake’s usually pancake-flat southern shoreline, with massive white lesions cropping up in areas which might be usually simply sand.

“We were very concerned,” Anderson informed me this spring. “One of our rangers contacted the Utah Geological Survey looking for answers.”

Geologists from the usreviewed pictures and took samples of the chalky white heaps and concluded they’re piles of salt referred to as mirabilite mounds, or Glauber’s salt. These uncommon geological formations happen when underground water reacts with minerals and burbles to the floor, intermingling with the chilly, winter air to type white crystals. Normally this portion of the lake can be coated in water and wouldn’t be vulnerable to this phenomenon, nonetheless, for the final a number of winters, the delicate mounds have turn out to be a standard incidence on the sandy lakeshore.

“In 2019, the first year we spotted them, there were about four formations,” Anderson stated. “But this year, we’ve recorded 15, the most we’ve ever seen. They’ve also gotten bigger, with one measuring three feet in height. Last year there was also one that was 35-feet long.”

According to the UGS, one attainable purpose why extra are growing is as a result of, because the mounds develop, “they eventually seal off their spring water source, causing the groundwater to find a new pathway to the surface,” inflicting new growths to develop.

In the three years since, lake ranges have dropped considerably, hitting file lows, which affords the proper circumstances for the mounds to type. According to the U.S. Geological Survey (USGS), in July 2021, common each day water ranges dropped an inch, the biggest identified dip since 1963 and the very best change for the reason that group started recording ranges again in 1847. On July 3, 2022, USGS reported that the lake had hit its lowest degree ever on file. Even with out these scientific measures, it’s apparent that lake ranges are severely low. At the Great Salt Lake Marina, a few five-minute stroll to the place the mirabilite mounds have been forming, the slips the place sailboats usually bob up and down within the water are dry, and other people have transported their boats to dry docks overlooking the marina. Research exhibits that the mounds start to type when the water’s elevation falls below 4,194 feet.

“When lake levels are higher, the underground springs are normally covered in salt water,” says Elliot Jagniecki, a senior geologist with the Utah Geological Survey. “So, they’re usually not visible, but with the lower water levels, now we can see them form.”

The Great Salt Lake is not any stranger to geological shifts, particularly as droughts have turn out to be extra rampant all through Utah and the remainder of the U.S. West. It’s the biggest saltwater lake within the Western Hemisphere, stretching roughly 75 miles in size and 35 miles in width and protecting 1,699 sq. miles, reaching depths of 33 ft. Today’s lake is outlined as a terminal lake, which means it doesn’t have any pure shops like rivers flowing from it and loses water primarily by means of evaporation.

The lake’s complete floor space has shrunk by greater than 40% since 1875, when federal monitoring started, in keeping with Audubon, because of issues like evaporation and agricultural practices. This shrinkage could be confirmed by satellite images that present the recession. Things have gotten so determined that native lawmakers have mentioned the outlandish thought of piping in seawater from the Pacific Ocean to fill the lake.

The lake we see at this time is definitely what stays of an excellent bigger physique of water referred to as Lake Bonneville that existed throughout the latest ice age. Lake Bonneville was huge, with an space of 19,800 sq. miles, or roughly 10 instances that of the Great Salt Lake. Much of the salt and minerals present in at this time’s lake are remnants from Lake Bonneville, ensuing within the sodium-sulfate-rich spring water that runs beneath the lakebed. This might assist clarify why the mounds are forming within the first place.

Another variable to their formation is that outdoors temperatures should be sub-freezing, which explains why mirabilite mounds are solely noticed on the shore throughout the winter. In order for the mirabilites to type, circumstances have to be an ideal mixture of sub-freezing temps and dry. This can be why related formations have been noticed in polar areas, together with Antarctica.

“We’re thinking the mounds are a response to a few things,” Jagniecki says, “including low lake levels, the arid climate, and low water input.”

In close by Salt Lake City, a number of native media outlets have reported on the mysterious mounds, drumming up curiosity, which led to the state park providing ranger-led excursions to the general public, with slots filling up rapidly. A neighborhood university has additionally began amassing samples to review the organic make-up of the formations. And a put up on the Utah State Parks Blog even identified a attainable Mars connection that might doubtlessly function an analog for researchers, for the reason that Red Planet shares related attributes to the lakeshore, together with being an arid surroundings.

“[The Mars connection] is more of a hypothesis and is based on satellite imagery,” Jagniecki says. “Images show that Mars does have topographic mounds that some researchers think could be similar in composition, but it’s still an unknown.”

The mounds disappear with the arrival of summer time, abandoning little greater than a skinny layer of white powder referred to as thenardite. However, if the previous few years are any indication, it’s doubtless that these ghost-like formations will sprout up once more quickly.

Jennifer Nalewicki is a Salt Lake City-based journalist. Her work has been featured in Smithsonian Magazine, Scientific American, Live Science, and extra.