A scuba diver swims deep into an oxygen-poor abyss. Does the water absorb all of their air bubbles?



Obviously a hypothetical scenario, but would a deep oxygen poor body of water absorb air bubbles before they could reach the surface?

In: Physics

No. Air diffusing into water is quite a slow process which is primarily dependent on surface area. When you’re breathing out from scuba gear, the bubbles will generally be fairly large and as compact as possible because of the pressure of the water. This really small surface area will limit the ability of the gas to diffuse into the water.

Most dissolved oxygen in water will come from agitation. Dividing the water into millions of smaller droplets will give it infinitely more surface area for oxygen to diffuse into and greatly enhance the speed of the process. When water is agitated, these smaller particles are being created all the time and will restore dissolved oxygen levels quicker.

If a diver was deep enough that the exhaled air bubbles could collapse under the pressure of the sea water, the diver is most likely long since dead due to that same pressure.

Some insignificant gas exchange occurs on the surface of the bubble as it rises to the surface. In an aquarium the bubbler mostly works to encourage water circulation to the surface, the rising bubbles also bring water to the surface, disturbing the water surface to encourage oxygen diffusion.