A picture posted to Facebook and other social media websites shows a massive “wave,” but it’s an optical illusion.
An explanation emerged of what the photo actually showed.
At first glance, it looks like a giant wave is headed for the beach, ready to crush anyone and anything else in its way.
The Sea Girt Beach Patrol in New Jersey posted the picture without context.
Turns out it’s not actually a water wave, but a fog bank.
A closer look confirms it, with added information from the National Weather Service in New Jersey.
The fog was “formed by warm air condensing over cold ocean water,” the U.S. National Weather Service for Philadelphia wrote on Facebook.
Still, other photos of the phenomenon are deceptive.
Fog “waves” can also occur far from the water in the mountains, as this video shows:
As Mother Nature Network notes, “The good news is that these fog tsunamis are relatively harmless, with visual impairment the only true danger for those caught within the wave of mist.”
The NWS says the phenomena takes place when warm air condenses over cooler ocean water.
“Once that happens, the sea fog bank forms and is transported by the prevailing wind,” stated meteorologist Morgan Palmer to NBC2. “If that wind is onshore, then fog will ride slightly inland.”
Depending on the time of day, temperature, and other weather conditions, they can take the shape of a wave or like something from a disaster film.