South Pacific Bare Zone

Oceanographers have discovered a patch of seafloor in the Southern Pacific Ocean that is almost devoid of oceanic sediments. To read the full article in Science News click here.

While most of the seafloor's basaltic oceanic crust is typically covered with a sediment layer hundreds of metres in thickness, "an unusual combination of circumstances" has left 2 million square kilometres of seafloor devoid of this sedimentary layer of organic and mineral sediments.

The reasons given for this patch of naked ocean floor are:

~ Regional waters are nutrient poor. Therefore, few organisms live here or are present to die, fall to the seafloor, and create biogenous sediment.

~ "The deepest waters in this area contain less carbonate and silica than other locations do, so skeletons of organisms that reach the seafloor dissolve."

~This region is distant from any landmass, and therefore has no source of windblown sediments that would settle on the bottom to create lithogenous sediment.

~ Little or no regional hydrothermal activity to produce dissolved minerals that would precipitate into volcanogenic sediment.

This lack of ocean sediment may allow researchers to study seafloor features that would otherwise be hidden, such as meteor dust.