"But hey, I thought you said the Dead Sea was deadly?"

Not to us. Humans are remarkably adaptable. We can swim in the Dead Sea, just like we can swim in the ocean. Well, people don't really "swim" in the Dead Sea - they just "hang out". That's what's so cool about the Dead Sea. Because of the extremely high concentration of dissolved mineral salts in the water its density is way more than that of plain fresh water. What this means is our bodies are more buoyant in the Dead Sea - so you bob like a cork. In fact, people are so buoyant in this water, it makes it kinda tough to actually swim. Most people like to just kick back in the water and read. It almost looks as though this guy is sitting on an air mattress that has sunk below the surface, but he's not. He's really just floating, without having to hold is feet in that position! If you think this is easy, try floating like this in a freshwater swimming pool.

What Caused the Dead Sea to Form?

This lesson takes us back to the subject of plate tectonics. In this part of the world there is a rift forming where two crustal plates are spreading apart. The East Rift Valley runs through most of Africa, starting north of the Dead Sea and running south along the eastern side of the continent. The Dead Sea is located right along the Rift Valley where the earth's crust is being stretched thin. To get an idea of how this "crustal spreading" thing works, take a bar of taffy, or taffy-like candy and try to pull it apart. You'll see where the candy starts to come apart it gets really thin just before it breaks. That's what is happening to the earth's crust in the Rift Valley. Where the earth's crust gets thin that part of the surface sinks downward. The Dead Sea is still continues to sink lower, even today. Scientists estimate that the Dead Sea lowers by as much as 13 inches per year. On a geologic time scale that's incredibly fast!

Why is the Dead Sea so Salty?

We talked about how the surface of the Dead Sea got down so low in elevation, but why is it so salty? All roads lead to the Sea when it comes to the rivers in the area. The Dead Sea is continually fed water from the rivers and streams coming down off the mountains that surround it. But the kicker is this....no rivers drain out of the Dead Sea. The only way water gets out of the Sea is through evaporation. And boy does it evaporate! This part of the world get plenty hot. When the water evaporates, it leaves behind all the dissolved minerals in the Sea, just making it saltier. In fact, it's through the dual action of; 1) continuing evaporation and 2) minerals salts carried into the Dead Sea from the local rivers, that makes the Sea so salty. The fact that the water doesn't escape the Sea just traps the salts within its shores.