Underwater Waterfalls!

So first off, we should be up front and honest here and let you know it’s not actually a flowing waterfall under the ocean, but a spectacular optical illusion that can be explained by the Indian Ocean’s fascinating geological history.

Mauritius is a relatively youthful island compared to much of the world, and was formed around 8 million years ago (to put that into context, Earth itself is an estimated 4.6 billion years old).

Volcanic activity under the ocean was the cause of the island’s formation along with other landmasses (including La Reunion Island) together known as the Mascarene Islands.


Milky Sea Effect

Milky seas, or mareel, is a condition on the ocean where large areas of seawater (up to 6,000 sq mi or 16,000 km2) appear to glow brilliantly enough at night to be seen by satellites orbiting Earth.

Modern science only tentatively attributes this effect to bioluminescent bacteria or dinoflagellates, causing the ocean to uniformly glow an eerie blue at night.

However, there is no modern research to prove that bioluminescent bacteria are capable of illuminating the ocean from horizon to horizon and for days at a time, as described in mariner’s tales for centuries (notably appearing in chapter 23 of Jules Verne’s Twenty Thousand Leagues Under the Sea); and, in fact, the effect has not been rigorously documented nor thoroughly explained, even in modern times.


Unexplained sounds

Underwater acoustics is the study of the propagation of sound in water and the interaction of the mechanical waves that constitute sound with the water and its boundaries.

The water may be in the ocean, a lake or a tank. Typical frequencies associated with underwater acoustics are between 10 Hz and 1 MHz.



brinicle (brine icicle, also known as ice stalactite) is a downward growing hollow tube of ice enclosing a plume of descending brine that is formed beneath developing sea ice.


Red Tide

Red tide is a common name for a phenomenon known as an algal bloom (large concentrations of aquatic microorganisms) when it is caused by a few species of dinoflagellates and the bloom takes on a red or brown color.

Red tides are events in which estuarine, marine, or fresh water algae accumulate rapidly in the water column, resulting in coloration of the surface water. It is usually found in coastal areas. It kills many manatees every year.



Pyrosomes, genus Pyrosoma, are free-floating colonial tunicates that live usually in the upper layers of the open ocean in warm seas, although some may be found at greater depths.

Pyrosomes are cylindrical or cone-shaped colonies made up of hundreds to thousands of individuals, known as zooids. Colonies range in size from less than one centimeter to several metres in length. They are commonly called “sea pickles.


Whirl Pools

whirlpool is a body of swirling water produced by the meeting of opposing currents. The vast majority of whirlpools are not very powerful and very small whirlpools can easily be seen when a bath or a sink is draining.

More powerful ones in seas or oceans may be termed maelstromsVortex is the proper term for any whirlpool that has a downdraft.


Rogue Waves

Rogue waves (also known as freak wavesmonster wavesepisodic waveskiller wavesextreme waves, and abnormal waves) are large, unexpected and suddenly appearing surface waves that can be extremely dangerous, even to large ships such as ocean liners.


Deepwater Photosynthesis

A team of researchers, including a photosynthesis expert from ASU, has found evidence of photosynthesis taking place deep within the Pacific Ocean. The team found a bacterium that is the first photosynthetic organism that doesn’t live off sunlight but from the dim light coming from hydrothermal vents nearly 2,400 meters (7,875 feet) deep in the ocean.


Check out the video for most Mysterious Ocean Facts!