Here is a closeup of the previous section, water depth is
shown on left, and color codes for temperature and salinity are once again listed on the
What is the change in water temperature from
the sea surface to a depth of 1000 meters directly
below the words "temperature" in the graph?
Since solar radiation from the sun does not
penetrate far into
the ocean, the water temperature decreases rapidly between 100 and 800 meters, this region
of decreasing temperature is called the thermocline.
Used with Permission of Matthias Tomczak ©Copyright 1997ight 1997
The region of rapid change in salinity with depth,
if it indeed exists in a particular region, is called
the halocline. Notice how the halocline is not as well-defined
(distinct) as the thermocline.
The increase in water density over this range of water
depth, which is caused by a combination of decreasing temperature and/or
is called the pycnocline.