An Essential Mineral
After eight days in Israel, a country full of fascinating features,traveling from the Western Wall in ancient Jerusalem to Hamat Gader, where hot springs and alligators are your onlycares, I didn't think anything could ever astound me again. That was until I saw the Dead Sea.I don't think I will ever forget the drive in our van going fromMasada to the Dead Sea. I remember very well driving down that mountain and looking at the sea below. There were signswritten in three languages-Hebrew, Arabic, and English-all along the way. They said 200 meters above sea level...100meters above sea level...sea level...100 meters below sea level...200 meters below sea level, all the way down to 400 metersbelow sea level.
That wasn't the only thing that occurred that day which was unforgettable. After we, my family and I, arrived at the Dead Sea, we went to a nearby restaurant. After having a small snack consisting of bourekas and a drinkof water, we got ready to go into the unrealistically hot water. Stepping into the Dead Sea was like stepping into a hotcup of tea. The average air temperature is 102ºF, even in the heart of the winter, and the water temperature reflectsthis heat.
When we were only up to our knees in the sea, we had trouble keeping our feet down. They would still floatup. It was like trying to keep a helium balloon on the ground; if you let the balloon go, it would rise up. When we were into the water up to our waist, we just let go and floated freely.The Dead Sea is one of the only seas where virtually nothing -- plants or animals -- can live. This is because it is so salty.
The Dead Sea, at 1,292 feet (394 meters) below sea level, is the lowest point on Earth. However, this has nothing to dowith why it is so salty. The high salinity level is caused by the increasing evaporation rate.Though seawater has a lot of salt, it has a number of other elements, too. "At least 72 elements are found in theseawater," said Martina Moran, a receptionist at the Salt Institute, in an e-mail interview. All of Earth's naturalelements occur in the sea.
Scientists don't yet have a full understanding of why the ocean is so salty, even though they have been studying it forover a century. All they know is that salt occurs naturally. However, there are many theories why the ocean became thisway. One is that, at the beginning of the world, storms, lightning, and rain created sea water that way. Some peoplebelieve that it began with the big bang theory.
I have never thought of salt as valuable. It just has always been there. After I did a little research, however, Irealized that salt isn't just "salt." Without salt, we wouldn't be able to survive. Human blood has salt, tears havesalt, and body cells cannot function without salt because it helps us cry and maintain nerve function. One quote thatproves this is: "A civilized life is impossible without salt." This was said by Pliny the Elder, a Roman writer, duringthe Middle Ages.
Common salt is called sodium chloride, or NaCl. Thesetwo elements are on the Periodic Table of Elements. The crystals come in the form of cubes. Under a magnifying glass,table salt looks like a bunch of tiny cubes, all combined together. Salt in its pure form can vary from clear to white.Salt's source is brine from seas, salt lakes, and other bodies of water. Even the underground sources come from brine.
Salt found underground is formed by the evaporation of river bodies and inland seas years ago.The use of salt apparently began way before there was any reported record keeping. As far back as 2,700 BC, historianshave found writings about salt published in China. The writings made up probably the first-known treatise onpharmacology. The earliest recordings show that salt was almost universally sought after byman.
I cooked water from the Atlantic Ocean and water from the Dead Sea to make it evaporate so I could see the saltcrystals. There were 473 ml of each (16 oz). The Atlantic Ocean water took 10 minutes to evaporate. As I was watching itevaporate, it started to bubble. There were little bubbles of salt all over my stove. When it was done, I put the saltin a bowl. There was approximately one tablespoon and a half a teaspoon of salt. The salt tasted very bitter, comparedto table salt. The Atlantic Ocean salt looked clearer than table salt. The Atlantic Ocean salt was also finer than thetable salt.
The Dead Sea salt was very captivating when Ievaporated it. It took about 50 minutes to evaporate 473 ml of water. Just as the Atlantic Ocean water did, the Dead Seawater bubbled all over my stove. When there was a little bit of water left, I started to stir it. I took some of thesalt from the pot and put it on a spoon and then put it into a different bowl. The salt would form a layer on top andbubble underneath. Taking the layer off was like peeling wax off something. As I looked at the salt in the pot, I couldsee that it looked exactly like glaze on a doughnut. There was more than a cup of Dead Sea salt. It was very hard andstayed hot for a long time. The Dead Sea salt tasted even more bitter than the Atlantic Ocean salt. The Atlantic Oceansalt and Dead Sea salt were the same whitish color, however. I was fascinated by the differences in salt between theDead Sea and the Atlantic Ocean.
The Dead Sea and the surrounding area are a great example of the importance of salt. I went to visit it as a routinepart of our vacation, not thinking much about why the Dead Sea was so famous, and left understanding so much more. I wasawestruck at how different two types of salt can be. Now I realize how valuable salt is. The next time I want salt atthe dinner table, I'll ask, "Can you pass the sodium chloride, please?"
"American Museum of Natural History." Retrieved from the World Wide Web on December 5, 2000: http://www.amnh.org
"The Dead Sea." Retrieved from the World Wide Web on November 13, 2000:http://www.deadseatourist.com/water.htm
"Dead Sea Travel Guide." Retrieved from the World Wide Web on November 13, 2000:http://www.deadseatravel.com
"Israel." Retrieved from the World Wide Web on December 7, 2000: http://www. lib.utexas.edu/libs/PCL/map_collection/middle_east_and_asia/Israel.GIF
"The JASON Project." Retrieved from the World Wide Web on December 7, 2000: http://www.jason.org
Jones, Helen Hinkley. Israel. Chicago: Children's Press, 1986.
Moran, Martina. E-mail interview by Frieda Shmuel. November 20, 2000.
Rogoff, Mike. Israel. Austin, Texas: Steck-Vaughn Library, 1991.
"Salt." The World Book Encyclopedia. 1993.
"Salt Made the World Go Round." Retrieved from the World Wide Web on November 15, 2000:http://www.salt.org.il/main.htm
"What Is Salt?" Retrieved from the World Wide Web on November 15, 2000: http://www.saltinstitute.org/15.html
More About This Resource...
This winning entry in the museum's Young Naturalist Awards 2001 takes a look at the saltiness of the Dead Sea. Frieda's essay with a field journal focus reports on:
- a family vacation to the Dead Sea, where the water's saltiness made it difficult to keep their feet underwater
- the reasons for the sea's salinity level, along with what scientists do and don't know about why the ocean is so salty
- an overview of the importance of salt to humans and salt's chemistry
- the results of her experiment comparing the evaporation rates of water from the Atlantic Ocean and the Dead Sea
Supplement a study of oceanography or chemistry with an activity drawn from this winning student essay.
- Send students to this online article, or print copies of the essay for them to read.
- Bring in a container of salt and look at its ingredients as a class, noting the addition of iodine.
- Have students investigate when we started adding iodine to salt and why, summarizing their findings in a brief essay.
OriginYoung Naturalist Awards