From the name ‘salt lake,’ it is clear that these lakes are saltier than a normal lake. Surprisingly, salt lakes can be even saltier than the ocean! They even contain different types of salt, including sodium chloride , or table salt.
Salt lakes can form in different ways. The Dead Sea is specifically formed because of large plates shifting under the Earth’s surface. Over a million years ago, the African Plate and the Arabian Plate shifted, causing a ditch to form. This ditch was originally connected to the Mediterranean Sea, so it was full of water. Over time, the plates shifted again, cutting the Dead Sea off from the Mediterranean Sea. This is why it now exists as a lake on its own.
How did this lake become so salty? After it was separated from the Mediterranean Sea, the water levels retreated, leaving behind much saltier water. In addition, the only remaining source of water is the Jordan River which sends both water and sediment into this lake. After the sediment settles, the salt content of the lake increases even more. There is nowhere for the water to go once it has reached the Dead Sea’s dead end.