The blue holes. Huge crevasses plunging into the depths of our oceans. These geological curiosities are still very poorly known, and it is rare to collect information on these strange underwater cavities. The largest of these is in the China Sea. The dragon’s blue hole sinks more than 300 meters below the surface. These fascinating places are increasingly studied around the world.
In recent years, missions have multiplied to better understand the seabed, and blue holes are no exception. During a dedicated scientific mission, a team from NOAA, the US agency for ocean and atmospheric observation, will take the road to Green Banana, one of the largest blue holes in the entire Atlantic, off the coast of the Florida.
Places that are difficult to access
This cave sinks more than 137 meters underground and was discovered by sinners. Should the expedition begin next month, with a second phase of diving in early 2021 in another Florida blue hole, called Amberjack Hole, and 72 meters deep.
The objective of the mission can be summed up simply. Understand how life develops in a blue hole. Scientists should make several readings, particularly on the level of nutrient present in the column. Life is very rare in these places, the water being static it is, logically, very poorly oxygenated. The expedition will try to find traces of microscopic life deep in the blue hole. These collections could provide information that should make it possible to determine whether Green Banana is, in some way, connected to the groundwater of the Florida plateau.
An unknown phenomenon
At the moment scientists are struggling to understand what is going on in a blue hole. In most cases these are caves, which were formed during the last ice age. At the time the sea level was a hundred meters lower. Then when the ice cap melted, the sea rose and the weight of the water caused the cave roof to collapse. Creating blue holes.
Due to their small size, it is impossible to lower a submarine into a blue hole. Only divers can descend into these abyss, which makes expeditions even more difficult. Thus, the Great Blue Hole of Egypt is tragically famous for being the tomb of many amateur divers. These tragedies have long slowed down scientific explorations to these underwater places hostile to all life. As a reminder, we know the bottom of our oceans less well than the lunar soil.