Varna.info : Facts : Bulgaria :

Black Sea, Bulgaria

Seen from atop the Ai-Petri Mountain, the Black Sea has an iridescent blue color. So naturally the question arises as to why the sea is called the black sea. But the fact is nobody really knows the true reason. It is speculated that since the sea can be pretty stormy in winter, the name was given to it by ancient sailors and pirates who were struck by its dark appearance when the sky turned black with storm clouds.

Location
The Black Sea is surrounded by six countries namely Romania, Bulgaria, Turkey, Georgia, Russia and Ukraine. Bulgaria and Romania share the western coastline of the Black Sea, while Russia and Georgia share its eastern shores. Ukraine is along the northern coastline while Turkey occupies its entire southern stretch.

The Black Sea is almost an inland sea except for a few straits that connect it to other seas. The Bosporus strait connects the Black Sea to the Sea of Marmara, which in turn connects to the Aegean Sea through the Dardanelles strait. The Aegean Sea opens out to the Mediterranean thereby connecting the Black Sea with it. It is believed that in ancient times when water levels were low, the Black Sea was a lake totally cut off from other water bodies. As water levels rose due to global climatic changes, it became connected to other seas through the straits mentioned above. Many archeologists believe that the catastrophic event that caused a rise in the level of sea water was in fact the Noah's Flood of the Bible.

Statistics
The Black Sea has a surface area of 168,495 Sq miles and reaches a maximum depth of 7,257 ft at its center. It has a total volume of 133,500 cu miles, out of which 188 cu miles flow into the Mediterranean Sea every year. The Black Sea also receives an inflow from the Mediterranean which is more salty than its outflow. The Don, Dnieper, Danube and many other rivers also pump fresh water into the Black Sea.

Some of the major cities along the Black Sea coast are Constanţa, Istanbul, Odessa, Mangalia, Burgas, Varna, Kherson, Sevastopol, Yalta, Kerch, Novorossiysk, Sochi, Sukhumi, Năvodari, Poti, Batumi, Trabzon, Samsun, Ordu and Zonguldak.

Hydrology
The Black Sea is unique since it has two distinct layers; an oxygenated upper layer which is about 200m deep which is teeming with life, and a ‘dead’ lower layer which is almost sterile. It is theorized that the lower layer may have formed when the Mediterranean flooded in with denser salt water which would have plunged straight to the bottom, leaving a diluted mix of fresh and salt water at the top. Rivers like the Danube and the Dnipro must have poured organic material into the new sea over thousands of years. Due to a lack of vertical currents, the inrush of organic matter might have been too much for the bacteria that would normally have decomposed it aerobically, resulting in a loss of oxygen in favour of hydrogen sulphide. Consequently the lower layer which forms 87% of the Black Sea's volume, is an almost sterile zone of water impregnated with hydrogen sulphide.

But recently some German scientists have discovered corals made by micro-organisms which are processing methane and sulphates in total darkness at the bottom of the Black Sea. These corals are now believed to be the world's oldest life forms.

Another peculiarity of the Black Sea is the bi-directional current which trades water with the Mediterranean. The surface current flows westwards through the straits into the Sea of Marmaris and into the Mediterranean, but the deep current which flows simultaneously in the opposite direction brings back water into the Black Sea.

Black Sea’s History
The Black Sea also had other names in the past. It was known as the Scythian Sea by the ancient Greeks, after the tribes that inhabited its shores at the time. The Scythians who plundered shipwrecked sailors usually made wine goblets out of sailors' skulls. The Greeks initially called it “Pontos Axenos” or the inhospitable sea. But after they settled in Crimea, they changed their minds and called it “Pontos Euxenos” or the hospitable sea.

It is widely believed that the Black Sea is packed with archaeological data yet to be unearthed. Submerged prehistoric settlements in the continental shelf and ancient shipwrecks in the anoxic zone are expected to be exceptionally well preserved due to the absence of oxygen. The Black Sea has witnessed the wars of the Hittites, Thracians, Greeks, Persians, Scythians, Romans, Byzantines, Goths, Huns, Avars, Bulgars, Slavs, Varangians, Crusaders, Venetians, Genovese, Tatars, Ottomans and Russians. The Black Sea was a significant naval platform for World War I and saw both naval as well as land battles during World War II.

Black Sea Tourism
Tourism is truly flourishing along the Bulgarian Black Sea coast. After decades of isolation, resorts such as Sunny Beach and Golden Sands are experiencing a new lease of life. Star hotels and luxury inns are sprouting up to accommodate a huge increase in tourists, a good chunk of which are British tourists, trying out Bulgaria for the very first time.