Thousands of years before Biblical times, during a period when temperatures were unusually high, the lands around the Dead Sea now occupied by Israel, Jordan and surrounding nations suffered droughts far worse than any recorded by humans. Warming climate now threatens to return such conditions to this already hard-pressed region. Scientists from Columbia University’s Lamont-Doherty Earth Observatory and other institutions are trying to better understand the distant past, and prospects for the future. (All photos: Kevin Krajick) READ THE FULL SCIENTIFIC STORY
In southern Israel, Lamont geochemist Yael Kiro views the Dead Sea, far below. She recently led a study showing that sediments drilled from deep under the sea’s bed indicate that regional rainfall plummeted tens of thousands of years ago, when temperatures rose to levels similar to those projected in the 21st century due to human-driven warming.
The Dead Sea is earth’s lowest point on land, with a shoreline that currently lies 1,400 feet below sea level. Here, a roadside attraction on the approach from Jerusalem.
The Dead Sea has no outlet, so salt builds up and precipitates out on its bed and shoreline, a process that has been going on for eons. Ancient crystallized salt from the bed contains the signs of past droughts.
Warming climate and overuse of the surrounding watershed by booming populations are already causing the sea’s level to drop about three feet a year. On the Jordanian shore, the team descends a giant staircase of recent previous beach lines. Each one marks a year’s decline.
Near the foot of Israel’s Mount Sodom, Lamont geoscientist Steven Goldstein (left) and Mordechai Stein of the Geological Survey of Israel inspect a salt cave thought to be 6 million to 7 million years old.
A salt crystal taken from the cave may contain subtle chemical signatures signaling shifts in temperature and rain.
Stein in the southern Jordanian desert, already one of the driest places on earth.
Kiro samples sand to aid with analysis of long-buried sediment layers.
Goldstein carves into sediments left by a long-vanished lake, now exposed on a cliff face in southern Israel.
A close look reveals alternating bands of light sediments and muddy dark ones, signaling dry and wet times respectively.
Today, a few hidden springs fringing the Dead Sea provide the only reliable water for many areas. This one is tucked into a small canyon, or wadi, in southern Jordan.
Hydrologist Marwan Al-Raggad of the University of Jordan tests water pH and temperature south of Amman, the capital city. Jordan depends heavily on dams and groundwater aquifers, but reserves are dwindling fast.
Near the Jordanian town of Dhiban, kids and their donkey cool off in a wadi during the late afternoon. Temperatures in this region routinely exceed 110 degrees F in summer.
In Jordan’s Wadi Hanzira, a pipeline carrying spring water parallels the remains of a Roman aqueduct. “You can tell by the ruins which springs have always been important for people,” says Goldstein. Most of the water goes for irrigation.
One result of declining Dead Sea levels: infrastructure once on the shoreline is now stranded. The Lido, a once-popular Israeli beachside restaurant, closed decades ago when the water receded. Now about a mile inland, its ruins are a minor tourist curiosity.
As groundwater levels decline along the sea’s shores, the earth is collapsing, and swallowing roads, buildings and entire settlements. This sinkhole in a recently abandoned Israeli highway rest area is estimated to be 150 feet deep.
Nearby, an abandoned gas station awaits its turn to go underground. It closed just a few years ago.
Near the Jordanian shoreline, sinking seawater levels are causing new wadis to erode out of soft, steeply downsloped sediments. In the Amman exurbs, Raggad and Kiro sample the walls of a wadi that formed recently. Israeli-Jordanian collaboration is uncommon, but under a common threat, the scientists hope to change this.
Amid a trickle of water, dead livestock litter the wadi’s floor–signal of a society under growing stress.