How Deep is the Black Sea, Really?

“When you’re testing to see how deep the water is, never use two feet.”

Benjamin Franklin

A Tale of Two Waters

Let’s begin exploring the depths of the legendary Black Sea and discover how deep it really is. It is nothing shy of a thalassophobic horror story so, be warned, you may want to sit this one out if you’re someone with thalassophobia. The Black Sea is a unique basin (layers of water that do not mix). Six countries border the Black Sea – Ukraine, Romania, Russia, Moldova, Georgia, Turkey, and Bulgaria. To add, it is the largest known basin. If the Black Sea sounds familiar to you, it is probably because many believe it is referenced in the world famous story of Noah’s Ark, but its significance goes far beyond its biblical references.

What makes the Black Sea who she is

It is an underwater graveyard overflowing with hidden tales and mysteries, and would certainly be a sight to see if you happen to be a scuba diver. Although, scuba diving does have its limits. Too bad the maximum scuba diving depth is roughly 350ft. I would like you to keep in mind that 350ft does not hold a candle to the deepest measured point of the Black Sea.

This mysterious deep sea lacks access to fresh water, which makes the water thick and dense, thanks to the excessive salt buildup. This density leads to a phenomenon called stratification. In the top layer, you’ll find oxygen, creating an environment where sea life thrives. While that may be true, high expectations for the entire sea to be rich in life would certainly disappoint. Now, fear not because the Black Sea has a ton of lore for you to sink your curiosity into. But for this article in particular, I would like to note that locals call it “The Sea of Dead Depths” for a reason. It’s home to only around 2,500 living organisms, including bottlenose dolphins, jellyfish, and tuna.

It’s an Entirely Different World in the Murky Deep

Let’s dive deeper, much deeper (quite literally), to somewhere not even the sun lives. In order to really understand the the Black Sea and where it earned its renowned title, consider what oceanic lasagna may look like. This sea holds a reputation for its layers. We have already discussed the surface layer and its ability to sustain life. Now, we are going to talk about the bottom layer, known as the anoxic zone. This is where things get really eerie. Imagine somewhere so empty that it even lacks oxygen. This zone starts around 230-300ft in the center and 330-500ft near the edges. Scientists label these waters “inhospitable.” In the deep, oxygen is not just scarce; it’s also tainted by tiny bacteria, viruses, and, not to forget, pollution.

To put it plainly, if you are looking for somewhere to go fishing or take a leisurely swim, the Black Sea would not be your best choice.

Anything but “a Breath of Fresh Air”

If you are a science or history buff, this next part is sure to keep you hooked (no pun intended). The high salt content gives the water incredible buoyancy on the surface.

A fun experiment about buoyancy:
All you will need is 3 cups, each filled with water, salt, baking soda, and 3 eggs. Fill one cup with mineral water, another with baking soda, and the last cup with salt water. Drop a grape in each cup of water.

Notice what happens in the denser water (the water that contains salt).

The egg floats!

On the other hand, this means that with the lack of oxygen, anything that sinks to the bottom is staying there. The anoxic zone experiences a slowed decomposition process, not only by a few days, years, or even decades – but by centuries. As a result, archaeologists have found incredibly preserved ancient relics, including a 2,400-year-old Greek ship. While the Black Sea may not be overflowing with life, you can think of it as an underwater museum, where history lies preserved beneath its surface. To clarify, some of the things found in its depths include deep sea canyons, left over pieces of ancient settlements, fossils, and even some clues about the evolution of marine life. “The Sea of Dead Depths” once again, living up to its many nicknames.

Now for the Depth… Yikes

The million-dollar question: how deep is the Black Sea?

To truly grasp the depth of the notorious Black Sea, let’s do a thought experiment. Consider the height of the Empire State Building: around 1,250ft (not including the tip). Now, let’s imagine stacking six Empire State Buildings on top of each other. Finally, drop them into the Black Sea’s deepest point. Assuming we had the equipment to execute this, the result would be roughly 7,500ft worth the skyscrapers in the water. That means only about 250ft would be peeking out of the water. In conclusion, that leaves a chilling 7,250ft below, making the maximum measured depth 7,270ft.

Just as any other sea bed or oceanic floor, it is a different depth depending on how deep in the water we go. I’ve mentioned before that this represents the deepest point we’ve measured. In other words, as far as we know, it doesn’t get any deeper. To put it differently, this could be a real nightmare for someone who’s afraid of the deep ocean.

Also, remember earlier in the article when I mentioned the maximum scuba diving depth being 350ft? Well, that is merely a fraction – only 20% – of how deep the Black Sea truly goes.

There is (as with many things) a wonderful lesson we can take away from this natural nightmare:

If you ever again wonder about the mysteries of the Black Sea, let its depth remind you that there is always more to what is inside than what lies at the surface.

The photo featured at the top of this post is © DOERS/Shutterstock.com