Salinity & Density
What unit is commonly used to measure the salinity of seawater?
Parts per thousand (ppt)
Energy passing through water is considered a __________.
Wave
What is the periodic rise and fall of the ocean's surface called?
Tides
What are gyres?
Large circular systems of surface currents.
What is the average pH of the ocean?
Approximately 8.2
What does the Rule of Constant Proportions state about seawater?
The relative proportions of the major dissolved salts remain relatively constant.
What is the primary source of energy for most ocean waves?
Wind
Tides are primarily caused by the gravitational pull of what two objects?
The Moon and the Sun
In which hemisphere do major ocean surface currents generally rotate counterclockwise?
Southern Hemisphere
Which two ions make up approximately 85% of the dissolved solutes in seawater?
Sodium and chloride
Which type of water is the most dense?
A. Warm and fresh
B. Warm and salty
C. Cold and salty
D. Cold and fresh
C. Cold and salty
Which of the following does NOT determine the size of a wind-generated wave?
A. Fetch
B. Frequency
C. Wind velocity
D. Wind duration
B. Frequency
How often do spring tides occur?
Approximately twice a month
What are deep ocean currents driven by differences in temperature and salinity called?
Thermohaline currents
How does the density of ice help aquatic life survive during winter?
Ice forms an insulating layer on the surface, allowing aquatic ecosystems to survive below.
How does temperature affect the density of water?
As temperature decreases, water density increases.
What is the lowest point of a wave called?
Trough
When do neap tides occur?
When the Sun and Moon are at approximately right angles to each other.
What is upwelling?
The movement of deep ocean water upward toward the surface.
What is ocean acidification primarily caused by?
Increased carbon dioxide in the atmosphere.
How does salinity affect the density of water?
As salinity increases, density increases.
What is the formula used to calculate wave speed?
Wave Speed = Wavelength ÷ Period
or
S = L ÷ P
What type of tide has two equal high tides and two equal low tides each day?
Semi-diurnal tide
Why is upwelling important to marine ecosystems?
It brings nutrient-rich water to the surface, supporting phytoplankton and marine food webs.
How does ocean acidification affect shellfish and other organisms with calcium carbonate shells?
It can weaken their calcium carbonate shells.