4.30 Oceanic Pressure
11,000 meters below the surface, the pressure is tremendous. You can see a video showing changes in water pressure
with increasing depth at this URL:
http://www.youtube.com/watch?v=dL08xX4lBQg
MEDIA
Click image to the left for use the URL below.
URL: http://www.ck12.org/flx/render/embeddedobject/5025FIGURE 4.57
Adjusting to Changing Pressure
Scuba divers can dive without special vehicles because they don’t go very deep below the surface of the water.
Nonetheless, because of the pressure of the water, scuba divers who go deeper than about 40 meters must return to
the surface slowly. They must stop for several minutes at one or more points in their ascent. That’s what the divers in
theFigure4.58 are doing. The stops are needed to let the pressure inside their body adjust to the decreasing pressure
of the water as they swim closer to the surface. If they were to rise to the surface too quickly, the gases dissolved in
their blood would form bubbles and cause serious health problems.
Q: Why would dissolved gases form bubbles as pressure decreases?
A: Less gas can dissolve in a fluid at lower pressure. Therefore, as pressure decreases, gases come out of solution
and form bubbles.
Summary
- As you go deeper in the ocean, the pressure exerted by the water increases. For each additional meter below
the surface, pressure increases by 10 kPa.