Everything Everywhere Daily: History, Science, Geography & More - Water, Water Everywhere, and Not A Drop To Drink

Episode Date: November 22, 2021

It covers 70% of the Earth’s surface and is one of the most common substances on Earth, and it makes up 97% of the water on the planet. Despite being so common, it is also one of the most complex substances you’ll ever encounter. You can swim and surf in it, but you can’t drink it. Learn more about seawater, and why there is a whole lot more to it than you probably realize, on this episode of Everything Everywhere Daily. Learn more about your ad choices. Visit megaphone.fm/adchoices

It covers 70% of the earth's surface is one of the most common substances on Earth, and it makes up over 97% of all our water. Despite being so common, it's also one of the most complex substances you'll ever encounter. You can swim in it and surf in it, but you can't drink it. Learn more about seawater, and why there is a whole lot more to it than you probably realize on this episode of Everything Everywhere Daily. Do you ever climb into bed ready to sleep, only to have your mind start racing the moment your head hits the pillow? Thoughts bouncing around, replaying the day or jumping ahead to tomorrow? That is exactly why Catherine Nikolai created Nothing Much Happens. Each episode is a gentle, cozy bedtime story where, well, nothing much happens.

No drama, no tension, nothing you need to follow closely. Just soft narration, calming repetition, and soothing sensory details designed to help your mind slow down and your body relax. It's not about entertainment, it's about rest. And millions of listeners around the world use it every night to quiet their thoughts and finally fall asleep. If you've ever struggled to shut your brain off at night, this might be exactly what you've been missing. You can listen to Nothing Much Happens wherever you get your podcasts.

Episodes are every Monday and Thursday. Believe it or not, I was 21 years old when I first saw saltwater. I was in Seattle and we drove past a park which was on Puget Sound. I was with a group driving up to the National Debate Tournament and I started yelling, stop, stop. They had no idea what was happening, so they stopped the van. I got out and I ran to the water to taste it. I needed to verify for myself that saltwater was indeed salty.

For many people around the world, my story was not something that they could fathom. 40% of humanity lives within 100 kilometers of the sea, and seawater is far and away the most common substance on the earth's surface. It's so common a substance that most people have never given it much thought. I mean, it's salt and water, right? What more is there to know? Well, as it turns out, quite a bit. Let's start by looking at exactly what it is. You'll not be surprised to find that the vast majority of seawater is, in fact, water and salt, sodium chloride, or an ACL. The salinity of seawater is usually said to be 3.5%, which means for every kilogram of water there would be 35 grams of salt. The salt is dissolved in the water in what is known as

an ionic solution. An ionic solution means that the individual sodium and chlorine atoms float around in the water by themselves. The sodium atom has a positive charge because it gets rid of an electron, and the chlorine has a negative charge because it takes on an electron. When the water evaporates, the negatively charged chlorine atom attaches to the positively charged sodium atom to make a solid that we know as salt. While water and salt make up the majority of seawater, there is a lot of other stuff in it. All of the rest of the contents of seawater make up less than 1% collectively. The next two most common components are magnesium and sulfur. These four elements, sodium, chlorine, magnesium, and sulfur are really the only ones that can be cheaply

and relatively easily extracted from seawater. Below that, you have calcium, potassium, bromine, and carbon. You can find almost everything in seawater, including iron, phosphorus, copper, cobalt, and even uranium. Some of these are actually very important, despite the fact that they may only be measured in parts per million or billion. The next question is, how did all this stuff get into the water? The first theories on the creation of seawater were developed by Sir Edmund Halley, the discoverer of Halley's comet. He hypothesized that it must have come from freshwater runoff from land. He wasn't totally wrong. Many elements in seawater do come from land, especially iron. Freshwater will pick up trace amounts of elements as it erode soil and rock. However, the majority of salt does not come from land erosion.

It actually has been there since the formation of the earth. Sodium probably came from the ocean floor, and chlorine probably came from outgassing from volcanoes. As a result, the amount of salt in the ocean has remained rather stable for much of Earth's history. It may become more or less dilute as the sea levels rise and fall, but the total amount of salt is pretty much the same. Is seawater the same all over the world? Well, not exactly. The level of salinity will vary based on latitude. At tropical latitude, seawater will have higher salinity because of higher temperatures and increased evaporation. Likewise, salinity tends to be lower in the polar regions for the same reason. This is why the part of the ocean with the highest salinity is in the Red Sea, which is a relatively

closed-off body of water which has little current and high temperatures. When salinity is higher, there is more salt in the water, and therefore the density is higher. This is a major part of the thermohaline circulation system. Thermo means heat and haline means salt. The thermohaline circulation system is the driving force behind global ocean currents and is a huge part of global weather systems and drives things like the Gulf Stream. Cold water with higher salinity will sink, and hotter, less saline water will rise to the surface, and it can take a thousand years for this cycle to complete. One component of seawater, which is not equally distributed globally, is iron. Iron mostly enters seawater via freshwater runoff. It's also an essential component in algae.

Most of the iron in seawater is found in coastal regions which are consumed by phytoplankton. By the time you get to the deep ocean, most of the iron has been consumed. That's why the deep oceans are considered a biological desert with very little marine life. It's also the basis for the idea of iron fertilization. The idea behind iron fertilization is to spread iron in the deep ocean to feed algae. The algae will bloom removing carbon from the atmosphere and then sink to the bottom of the ocean when it dies. Proponents believe it would be a cheap, effective way to remove massive amounts of carbon from the atmosphere. Speaking of carbon, it usually finds itself in seawater in the form of dissolved carbon dioxide.

Dissolved carbon dioxide can react with water to form carbonic acid, and this is the same stuff that's in carbonated drinks. Seawater is naturally a weak base with a pH slightly above 7, round 7.5. Carbonic acid is the primary reason for the reduction in pH and the acidification of seawater. Another really important element in seawater is calcium. If it wasn't for calcium, there would be no seashells or hard coral. If you look closely at white sand on a white sand beach, you'll notice that it's mostly ground-up shells and coral. In some places, calcium can become so saturated in seawater that it will precipitate out of the water directly. This happens in the Bahamas. If you look at a satellite image of the Bahamas, you'll see lots of very

light blue water. This color comes from the calcium carbonate, which precipitates out of the water directly. There's also a lot of organic matter in seawater. There are bacteria located from the surface of the ocean to the seafloor. We haven't even identified most of the bacteria in the ocean. It's estimated that a single liter of seawater can have 20,000 different species of bacteria. And this is on top of all the diatoms, phytoplankton, and zooplankton, which are also found in seawater as well. Sea water can and does freeze, but it requires temperatures lower than freshwater. The free The freezing point of saltwater changes with salinity, but normal seawater will freeze about negative 2 Celsius or 28 degrees Fahrenheit. Because changing the salinity of seawater will change its freezing point, one of the best places to view polar bears in the world is in Churchill, Manitoba.

The reason why is because it's where the freshwater Churchill River empties out into the saltwater Hudson Bay. Also, the cold Hudson Bay water flows counterclockwise, crashing into the river mouth as it flows south. That means the area around the river will usually freeze first because the freshwater is reducing the salinity of the water around the river, making it easier to freeze. Polar bears have figured this out, and assemble there waiting for the sea ice to come in so they can go and feed on seals. I was there several years ago when the ice came in late, and we saw a 43 polar bear in one day, and it was all due to the freezing point of seawater.

One question that people have about seawater is, why can't we drink it? We drink water, we eat salt, why can't we consume them together? Well, technically you can. It all has to do with the amount of salt. Your body can regulate the amount of salt in your system. In fact, it has to regulate it within certain narrow parameters. And it removes excess salt via your kidneys and water. The problem with consuming salt water is that the amount of water your body needs to expel the salt is greater than the amount of water you're consuming with the seawater. This is why drinking seawater will actually make you more dehydrated.

Drinking a small amount won't hurt you, and you can easily counterbalance it by just drinking some fresh water to help flush out the salt. The fatality rate of people in life rafts who drank seawater was 39% versus 3% for those who didn't. That being said, there have been cases of people in survival situations who have claimed to have survived drinking two cups of seawater for every three cups of fresh water. I wouldn't recommend doing this unless you are in. in an extreme survival situation, but it's handy information to know. There are some recipes

that use seawater for food. It was sometimes used in ancient Rome as an additive to wine. In the Canary Islands, potatoes will be cooked in seawater and then dried in an oven to make salt crystals form on the outside. How do you separate salt from water? The process is called desalimization. It involves turning the liquid water into a gas, either through boiling or evaporation, or through a process known as reverse osmosis. One popular desalcation, one popular desalimization. One popular desalination technique is called multi-stage flash distillation. Warm water is put in chambers at ever-lower pressures such that the water temperature is above boiling at that pressure. As it goes from chamber to chamber, more water boils away, leaving behind brine. Reverse osmosis tends to be cheaper. It's basically a membrane

that doesn't allow ions in the water to pass through it. What about the opposite? How about getting salt from seawater? That process is pretty ancient and pretty simple. You can fill pools with water and then just let the sun evaporate the water. When it evaporates enough, you have sea salt. Here's a fun fact you might know, but all salt is sea salt. It's just a matter of when it was evaporated. If it is sold as sea salt, then it was probably evaporated recently. If it's just plain old table salt, then it probably came from a salt mine, which was just evaporated sea salt for millions of years ago. I took a class in X-ray spectrography years ago, and for my class project, I analyzed different types of table salt. Results, it's all pretty much the same thing chemically.

The main thing which affects taste is actually the size of salt grains. So, even though you may have never given it a thought, there is a lot going on with seawater. The stuff that makes up most of our world is not surprisingly, the very thing that drives much of the world as we know it. The associate producers of Everything Everywhere Daily are Peter Bennett and Thor Thompson. If you'd like to support the show, please join the list of patrons over at patreon.com. And also remember, if you leave a review or send me a question, you too can have it read on the show. It was capable of removing the salt from over 500 million gallons of seawater a day. Do you realize what that could mean to the starving nations of the earth?

Wow. They'd have enough salt to last forever.