Sisters in Salinity

Posted · Add Comment

Sisters in Salinity

This winter, with the Dead Sea scrolls visiting our city, it’s easy to feel some kinship with the distant place they came from, a familiar-seeming place of drought and sand left stranded with a sea so salty not even fish live in its waters.

Though both the Dead Sea—called Yam Hamelakh or “the salt sea” in Hebrew—and the Great Salt Lake are terminal waters, in size and salinity they vary considerably. At 34 miles long, the Dead Sea’s width ranges from two to 11 miles. It is the deepest hypersaline lake in the world (1,000 feet). The Dead Sea’s shape is like a deep bowl to the Great Salt Lake’s flat platter.

The Dead Sea maintains a fairly constant 31.5% salinity, easily outcompeting Great Salt Lake (around 13%; although north of the Union Pacific causeway that divides the lake, salinity levels measure closer to 26%). This is, in part, because of the Dead Sea’s location between Jordan and Israel and the West Bank. Settled in a consistently hot and dry climate at 1,400 feet below sea level, higher temperatures cause more evaporation, concentrating the salt.

Exploring these two water bodies’ differences and similarities, at a time when the Dead Sea appears in danger of disappearing, provides an important opportunity to learn from and avoid our sister sea’s problems.

Beginnings

Though scientists can only theorize about the events that created the Dead Sea, most agree that it began nearly three million years ago as a small bay on the Mediterranean. Shifts in the earth’s crust—tectonic or seismic—and shifts in climate eventually trapped the lagoon’s waters inland, securing along with them a deposit of salt nearly a mile deep that had built up over thousands of years.

At the same time, on the other side of the globe, a series of ancient lakes were forming and disappearing across the expanse of the Great Basin. Around 32,000 years ago, long after the Dead Sea was cut off from its parent water, the last of the Basin’s lakes formed: Lake Bonneville, aquatic precursor to the Great Salt Lake.

Helped by a regional climate that produced prodigious precipitation along with cool temperatures that slowed evaporation, the waters of Bonneville began to accumulate, stretching across parts of what we now call Utah, Idaho, Nevada and Wyoming. When an earthen dam suddenly collapsed 14,500 years ago, Bonneville emptied, leaving the terminal waters of the Great Salt Lake, a comparatively small puddle, at the basin’s lowest point.

Humans

Starting around 400 BCE, humans appear to have formed a close spiritual relationship with the Dead Sea. Archeological findings along the sea’s shores reveal not only the Dead Sea Scrolls, but also the remains of a Chalcolithic temple and ritual objects made of metal and stone. Into modern times, the salty waters have attracted vacationers and spiritual and health seekers alongside scientists who closely study the region’s flora, fauna and geology.

Back in Utah: We may not have temples, but we do have evidence that people lived near and made use of the Great Salt Lake. In 1984, archaeologists from the Utah State Historical Society discovered a massive deposit of grasshopper parts in Lakeside cave, along with scatalogical proof that humans had been eating the protein-rich insects. In a 1989 Natural History magazine article, then-Utah state archaeologist David Madsen described coming across windrows of salted, sundried grasshoppers along the lake’s eastern edge. The insects had been blown into the water and washed up in rows as wide as six feet, at nine inches deep, that went on for miles. Madsen estimated one person working for one hour along the shore could gather 18.5 pounds of grasshoppers, at 1,270 calories per pound. Even though it was too salty to bear fish, the Great Salt Lake provided.

“White settlers found an undrinkable lake in an unforgiving landscape,” says Bonnie Baxter, professor of biology at Westminster Col­lege and director of the school’s Great Salt Lake Institute. They did, however, find it entertaining. Resorts, including the famous Saltair, “Voney Island of the West,” were built along the south shore. Visitors came from afar to bob like a cork in this salty lake. But the fickle water level made these enterprises bad longterm investments.

In the last five years since the In­sti­tute began, professors and students have begun gathering important information about the lake’s chemistry, microbiology, biology and geology, research that would have been considered laughable at the turn of the 20th century. Great Salt Lake is also now acknowledged as a world-class flyway for water birds.

In 1934 the only attention worthy of “nature’s little joke,” according to the Utah Water Storage Commission and the United States Department of Agriculture, came in the form of a plan to desalinate the waters. By running a dike system from the south end of the lake across Antel­ope and Fremont Islands and connecting to Promontory Point in the north, planners hoped to fill a 600-square-mile artificial basin with fresh waters from the Weber, Jordan and Bear Rivers for culinary and agricultural use.

The plan lost momentum and never came to fruition, in part because of the start of the World War II, and except for the causeway and a few small dikes and evaporation ponds, the lake has remained comparatively free to ebb and flow naturally. The same cannot be said for the Dead Sea.

Source water grab

Most of the water in the Dead Sea comes from a single source, the Jordan River. In the 1950s, nearly 1,300 million cubic meters (mcm) of water flowed from the Jordan into the lake annually. Today, discharge levels range from 20 to 200 mcm. As a result, the Dead Sea has fallen over 80 feet and lost a third of its surface area. In last year alone, the Dead Sea dropped nearly five feet.

As we in the West can relate, the source of this problem can be traced to the need for fresh water. As water flows downstream toward the Dead Sea from its origin in the Anti-Lebanon and Mount Hermon ranges, it passes by 7.18 million people in five countries—Syria, Lebanon, Jordan, Palestine and Israel—where it is diverted at every turn.

Forty-five dams stand between the mountains and the sea. Syria, the second-heaviest user of the region’s water supply, has no direct access to the Jordan River but it does have several dams along the river’s tributaries from which it takes about 450 mcm of surface and groundwater per year. Israel is the largest user, taking 580 to 640 mcm annually. Jordan, Palestine and Lebanon use the least.

It’s the kind of uncoordinated water grab that could alter any body of water, especially in an arid region. The Great Salt Lake would be particularly susceptible because of its wide, shallow shape. With an average depth of merely 14 feet, even natural seasonal ebbs and flows can raise or lower the lake levels by one or two feet and move the shoreline as much as a mile. With the lake currently sitting a few feet below the average elevation level, some at the Great Salt Lake Institute are starting to be concerned.

Great Salt Lake Institute coordinator Jaimi Butler has been monitoring bird populations on the lake since 1999. “Our watershed covers 22,000 square miles over four states,” she says. Similar to our salty sister, “Our water moves through geographical and political boundaries and we don’t always have a say on what happens to it in those places before reaches the lake.”

Compounding the problem of widespread water use is drought. Baxter recalls waiting expectantly for the lake levels to rise back to normal after a recent heavy snow season, but the water never came. After years of inadequate snows, upstream demands on the water supply were just too heavy. Ground water needed replacing, reservoirs needed filling. By the time the runoff was over, little was left for the water’s last stop at the bottom of the basin. “It was the first time,” recalls Baxter, “that I have ever seen the lake not respond to snowfall.”

Fate of the lakes

Saline lakes have disappeared before. The Aral Sea once lay between Kazakhstan and Uzbekistan, but a 1960s Soviet Union irrigation project began diverting water from the sea’s two major inflowing rivers. By 2000 the sea was reduced to nearly half its original size and separated into two smaller sections. Today, not much remains of the lake.

In a last-ditch effort to avoid a similar fate, leaders from Israel, Palestine and Jordan agreed earlier this year to an ambitious new project to save the Dead Sea. Instead of implementing water conservation measures, the plan involves creating a 110-mile-long water pipeline between the Red and the Dead Seas. Pumps will push water from the Red Sea north in an attempt to refill the sea’s disappearing neighbor. The project also includes one reservoir, two desalinization plants and two hydropower plants.

The project’s $1 billion price tag shows just how important it is for these countries to hold onto the Dead Sea, a site of historical, religious and scientific importance and a point of identity for the region.

Should we some day be faced with a shrinking lake, would we be willing to step in and save “nature’s little joke” or would we casually watch it slip away?

For Bonnie Baxter, the Aral Sea and the efforts for the Dead Sea serve as sobering warnings that make the answer to that question quite clear. Since the Aral Sea’s lakebed started drying up, airborne dust contaminated with agricultural chemicals has created a new public health hazard, certainly nothing that we would want to mix with our already-toxic winter inversions. Where the Aral’s dust settles, soil is contaminated.

And for those who think our summers are already getting too hot, seasonal extremes in the Aral Sea’s region are now, without the moderating influence of the lake’s water, more pronounced than ever.

Surveying the hyper-salinated seas

Great Salt Lake and the Dead Sea are not alone on this planet. In the frigid Antarctic lives a lake that never freezes. Called Don Juan Pond by scientists, it is the most saline body of water in the world, formed by daily temperature fluctuations that send ice melt seeping through a nearby sediment patch of calcium chloride.

Far away from Antarctica, in India, rests a sister saline lake called Lonar Lake, perfectly round and formed by a long-ago meteor impact.

Deep in the outback of Australia, along the coast of California, in Romania, saline lakes are everywhere.

But none are quite as famous as the Dead Sea and the Great Salt Lake.

 
 
X