In an interdisciplinary research project coordinated by the Helmholtz Centre for Environmental Research (UFZ), scientists have discovered meter-high chimneys on the floor of the Dead Sea. These unique formations are the result of the spontaneous crystallization of minerals from highly saline groundwater that rises from deep within the lake’s floor. This discovery, published in Science of the Total Environment, offers new insights into the geological dynamics of the region.
Importance of the Discovery
The chimneys, which are a first-time discovery, serve as an important early warning indicator for sinkholes in the Dead Sea area. Sinkholes are subsidence craters that have been forming in the region for decades and pose a significant risk to local populations. As the Dead Sea continues to shrink, these dangerous formations are becoming more prevalent, leading to concerns about their impact on infrastructure and agriculture.
Decline of the Dead Sea and Its Consequences
The Dead Sea, located between Israel, Jordan, and the West Bank, has been experiencing a drastic decline in water levels. The lake has been dropping by roughly one meter per year for over 50 years due to a combination of reduced inflow from tributaries and high rates of evaporation caused by drought and heat. As a result, the surface level of the Dead Sea is now approximately 438 meters below sea level.
This decline has significant consequences for groundwater systems in the surrounding areas. The lowering of the Dead Sea’s water level is causing a drop in the groundwater level, which makes it increasingly difficult for neighboring countries to access water resources from underground aquifers.
Groundwater Dynamics in the Region
Dr. Christian Siebert, a hydrogeologist at UFZ, has been studying how the dynamics of the groundwater system in this region are changing. Over the years, he has focused on how aquifers are altering their paths through rock layers both on land and beneath the Dead Sea. A team of divers he deployed discovered the unique chimney-shaped vents on the lake’s floor, which emit a shimmering fluid.
Black Smokers vs. White Smokers
The vents discovered in the Dead Sea bear a resemblance to black smokers found along mid-ocean ridges. However, the systems are fundamentally different. Black smokers emit hot water containing sulfides at great ocean depths, while the chimneys in the Dead Sea discharge highly saline groundwater.
The explanation for the salt in the groundwater is that it leaches out mineral-rich layers, particularly halite (rock salt), from the lake’s surrounding sediments. This highly saline brine rises because of its lower density compared to the surrounding water, creating a jet-like effect. Upon contact with the Dead Sea water, salts crystallize and form the chimney-like structures.
Significance of the White Smokers
The chimneys, or “white smokers,” are especially important as they act as early warning signals for sinkholes. Sinkholes are formed by the dissolution of massive salt layers beneath the surface, creating large cavities that can cause the ground to collapse suddenly. The white smokers indicate areas where this process is active and can potentially predict where a collapse might occur.
The team’s findings show that the chimneys have formed in areas where the ground has already experienced subsidence, suggesting that these regions are at high risk for further collapse. This makes the white smokers a valuable tool for forecasting sinkhole-prone areas.
Mapping the Chimneys for Risk Assessment
To effectively predict sinkholes, autonomous watercraft equipped with advanced sonar systems, such as multibeam echosounders or side-scanning sonar, could be used to map the chimneys with great precision. This would enable scientists to identify areas that are at immediate risk of collapse, providing a more accurate and efficient method of monitoring the region’s geological stability.
Multiple-Choice Questions (MCQs):
- What causes the chimney-shaped vents discovered on the floor of the Dead Sea?
- a) Volcanic activity
- b) Spontaneous crystallization of minerals from groundwater
- c) Underwater earthquakes
- d) Sedimentation of minerals over time
Answer: b) Spontaneous crystallization of minerals from groundwater
- What is the primary role of the discovered chimneys in the Dead Sea?
- a) To indicate areas where volcanic activity is happening
- b) To serve as an early warning for sinkholes
- c) To help monitor water temperature
- d) To provide a habitat for aquatic life
Answer: b) To serve as an early warning for sinkholes
- How does the salt in the groundwater near the Dead Sea come about?
- a) From the evaporation of water in the lake
- b) From the leaching of salt from the surrounding rock layers
- c) From seawater entering the lake
- d) From salt mining operations
Answer: b) From the leaching of salt from the surrounding rock layers
- What is a key difference between black smokers and the white smokers discovered in the Dead Sea?
- a) Black smokers emit cold water, while white smokers emit hot water
- b) Black smokers are found in the ocean, while white smokers are found in saltwater lakes
- c) Black smokers emit sulfides, while white smokers emit highly saline groundwater
- d) Black smokers are larger in size than white smokers
Answer: c) Black smokers emit sulfides, while white smokers emit highly saline groundwater
- What technology could be used to map the white smokers with precision?
- a) Satellite imagery
- b) Autonomous watercraft with sonar systems
- c) Drones equipped with thermal cameras
- d) Ground-penetrating radar
Answer: b) Autonomous watercraft with sonar systems