Physical Oceanography Chapter 15

Major Oceans The three major oceans are : 1._______-largest, deepest, coldest, least salty. 2.__________- second largest, shallow, warm, salty. 3. _________- intermediate in depth, temperature, and salinity. The three major oceans are : 1._______-largest, deepest, coldest, least salty. 2.__________- second largest, shallow, warm, salty. 3. _________- intermediate in depth, temperature, and salinity. The _______Ocean near the north pole, and the ____________ Ocean near the south pole contain vast expanses of sea ice. The _______Ocean near the north pole, and the ____________ Ocean near the south pole contain vast expanses of sea ice. Pacific Atlantic Indian Arctic Antarctic

Methods of Studying the Ocean The Topex/Poseidon _____________ orbits 1331 km above the Earth, gathering information about the oceans. _____________ maps ocean floor topography by timing how long it takes sound waves to bounce off the ocean floor. Underwater vessels called _________________ investigate the deepest ocean trenches. satellite Sonar submersibles

Sonar (also called echo-sounding) Sound waves travel how fast in seawater? Sound waves travel how fast in seawater? How deep is the water if it takes ten seconds for the sound wave to go from ship to ocean floor and back to ship? How deep is the water if it takes ten seconds for the sound wave to go from ship to ocean floor and back to ship? 1,454 m/s 7,270 m Calculation: (10 s times 1,454 m/s divided by 2 )

The picture below is of a _____________. The picture below is of a _____________. submersible

Salinity The amount of salt per unit water is known as salinity. The average salinity of seawater is _____ ppt. Therefore, for every 1,000 ml water, there are ___ grams of dissolved salts. The most abundant salt in seawater is ________, but there are many other salts present in the form of ions. Near the equator salinity is __________ than average due to ___________________. Near the poles salinity is __________ than average due to _______________. In the Mediterranean the salinity is __________than average due to __________. NaCl lower greater precipitation lower melting sea ice higher evaporation

Natural Processes Affecting Salinity

The salinity here would likely be: A.35 ppt B.34 ppt C.36 ppt

Colorful Seawater What makes the ocean water in the picture to the left different colors? What makes the ocean water in the picture to the left different colors? Why would a shrimp that appears bright red at the surface appear black at greater depths, and why might this be beneficial? Why would a shrimp that appears bright red at the surface appear black at greater depths, and why might this be beneficial? differences in depth Longer (red) wavelengths are absorbed before reaching deep water. Shrimp can hide and not become a meal.

Ocean Temperature Variation  The ocean’s surface water temperature varies with the amount of solar radiation received, which is primarily a function of latitude The Composition of Seawater The thermocline is the layer of ocean water between about 300 meters and 1000 meters where there is a rapid change of temperature with depth. The thermocline is a very important structure because it creates a barrier to marine life.

Variations in Ocean Surface Temperature

Variations in Ocean Water Temperature

Ocean Density Variation  Density is defined as mass per unit volume. It can be thought of as a measure of how heavy something is for its size The Composition of Seawater Seawater density is influenced by two main factors: salinity and temperature.  Factors Affecting Seawater Density

Ocean Density Variation  Density Variation with Depth 15.1 The Composition of Seawater The pycnocline is the layer of ocean water between about 300 meters and 1000 meters where there is a rapid change of density with depth.

Variations in Ocean Water Density

Ocean Layering  Oceanographers generally recognize a three-layered structure in most parts of the open ocean: a shallow surface mixed zone, a transition zone, and a deep zone The Composition of Seawater  Surface Zone Sun-warmed zone Zone of mixing Shallow (300 to 450 meters)

Ocean Layering  Transition Zone 15.1 The Composition of Seawater  Deep Zone Constant high-density water Temperatures are just a few degrees above freezing. Sunlight never reaches this zone. Thermocline and pycnocline Between surface layer and deep zone

Ocean Layers Surface layer Thermocline Bottom layer

Label the wave diagram below with the following terms: wavelength, waveheight, trough, crest Ocean Movements trough crest wavelength waveheight

Tides Label the key with the correct tide cycle names: semidiurnal mixed diurnal

Match the following terms to their correct letter in the diagram: A B C D E D F G H Island Continental shelf Continental slope Abyssal plain Seamount Continental rise Trench Guyot Seafloor Topography A.A. B. C.C. D.D. E. F. G.G. H.H.

Listed below are some of the major surface currents. The force which generates these currents is ____________. wind

Chapter Review 1.What is the average salinity of seawater? 2.What is the deepest area of the seafloor? 3.What is the largest ocean? 4.Why is the ocean “blue”? 5.What is the force responsible for surface currents? 6.What causes density currents? 7.What causes tides? 8.List the 3 tidal patterns. 9.What is the highest part of a wave called? 10.Name the ocean that borders Virginia. 35 ppt trench Pacific shorter wavelengths not absorbed wind differences in temperature and salinity gravity of the sun and moon diurnal, semidiurnal, mixed crest Atlantic