Unit 7 Day 2 Notes
Seawater
Objective
1. Describe the
and
variations in
2. Explain ocean layering and effects of temperature
differences
3. Describe variations in
and
Seawater
•
•The water of the world’s ocean is
and
Seawater is a solution of about 96.5% water
dissolved salts
•Although
and
are
the most abundant nearly all naturally occurring
elements on Earth (including gold and silver) are found
in seawater
Chemical Properties of Seawater
•The most important factor oceanographers study is
the
of seawater
•This includes the levels of
as well as
and
that greatly affect life in the oceans
of crustal rocks generates
most of the other abundant ions
•
,
and
come from the weathering of feldspars
•Salt ions are continuously added to seawater yet the
. They are removed
from the ocean at the same rate as they are added
•Salts precipitate from seawater near
regions
•Small, salty spray droplets from breaking waves are
Physical Properties of Seawater
composed of
positively charged ions and negative ions so that the
product is electrically neutral (without a net charge)
amount of
•
picked up by winds and deposited inland
•Salts are
•
chlorine
and sulfur as they dissolve in seawater
is the measure of the
in seawater
•Salinity can
•The presence of the various salts causes the physical
properties of seawater to be
freshwater.
•Seawater is
the salt ions are
from
than freshwater because
than water molecules
between 3.2% and 3.7%
depending on location, precipitation and temperature
•
also varies with
affecting many significant oceanic processes
•Common major ions in seawater are
•Geological evidence indicates that the
the ocean has
•The
of
over time
of seawater is
because salt ions interfere with the formation of
hydrogen bonds
9
Water Masses
•Since seawater is fluid the
result in horizontal as well as vertical movement and
cause deep water
throughout the
world’s ocean
•Seawater absorbs different light wave frequencies
•
only occurs
100m
•When
the sea ice
formed
the salt ions.
These ions remain in the unfrozen seawater causing it
to become more
to the
bottom
•This Antarctic Bottom Water then
as a cold,
deep water mass along the ocean floor
•North Atlantic Deep Water forms in a similar manner
•Ocean water
offshore from Greenland, but it is warmer and less
dense than Antarctic Bottom Water so it overrides it
Ocean Layering
significantly
The oceans are divided into
three layers by density differences
•
is
to the bottom
•Antarctic Intermediate Water
the
other two masses
so it
•The surface layer is relatively warm and is about
100m thick
•The
is the transitional layer characterized by
with depth
10
•The
with temperatures
•
layer is