A historic shot of the sea floor in 1991 was taken from the submersible Alvin where scientists found themselves in something that looked like a snowstorm on the bottom of the sea. As the institution reports:
They had arrived soon after a seafloor volcanic eruption in which hydrothermal vents spewed huge volumes of white bacterial matter into the ocean at 9°50’N on the East Pacific Rise at a depth of 2,500 meters (8,250 feet).
The ocean, on average, is 4,267 meters (14,000 feet) deep. The deepest part of the ocean is called the Challenger Deep and is located in the southern end of the Mariana Trench (of the West Pacific Ocean). Challenger Deep is approximately 11,030 meters (36,200 feet) deep. It is named after the HMS Challenger, whose crew first sounded the depths of the trench in 1875.
This picture was taken in the Atlantic however. Rachel Haymon (UC Santa Barbara) and Dan Fornari (WHOI) were chief scientists on the expedition that made the first direct observation of these so-called “snowblower” vents and offered initial clues to a “deep biosphere” with potentially large populations of microorganisms living within the ocean crust at mid-ocean ridges.