From CBS News:
Off the coast of Florida, deep at the bottom of the ocean, are massive blue holes that formed thousands of years ago. What the unexplored holes contain has remained largely a mystery — but now, scientists want to change that.
Green Banana is located about 155 feet below the water’s surface, according to the National Oceanic and Atmospheric Administration (NOAA). It was first discovered not by researchers or scientists, but by fishermen and recreational divers, and is similar to sinkholes found on land.
NOAA said that there are many underwater sinkholes, springs and caverns scattered across Florida’s Gulf continental shelf — but they have no idea how many exist.
According to researchers at Mote Marine Laboratory, the holes likely formed roughly 8,000 to 12,000 years ago, when the Florida coastline was about 100 miles further offshore from where it is now due to lower sea levels.
To read more about these fascinating blue holes and the scientists that are dedicated to learning more about them, click here.
And to watch an interesting video on the subject, see below!