Imagine that you have taken a time machine back to the early 1900s and are meeting Alfred Wagner for lunch. He is very depressed because almost no one believes his theory of continental drift. Explain to him how science in the decades after his death will confirm his theory and expand it into the larger theory of plate tectonics. In your explanation to him, be sure to explain: Key discoveries about the ocean floor that happened since his day. (Note: in Wagener’s day, almost nothing was known about the ocean floor. Think about how that later changed and how it relates to continental drift.) And evidence that proves that the seafloor spreads and that the earth’s surface is divided up into moving plates. (Hint: this evidence includes paleomagnetism, the age of the seafloor. heat flow, and earthquakes.)
THE ORIGIN and PROPERTIES of Water
What processes do scientists think occurred early in the Earth’s history that produced the Earth’s water, including what oceans ?
Water (H20) is a polar molecule. what does this mean, and what effects does water’s polarity have on its properties?
What is salinity, and what processes control ocean waters salinity (that is, cause salinity to go up or down)?
OCEAN CIRCULATION
The circulation of the oceans is driven by two main processes: 1) The prevailing surface winds, 2. Differences in density between various water masses. The Coriolis effect also includes the movement of ocean currents. Use these concepts to explain: The movement of surface currents particularly the subtropical gyres and The moments of deep (thermohaline) Ocean currents and the concept of “conveyor belt circulation”
COASTLINES & SOCIETY ● evaluate the effects of ways on the moving of beach sand and the resulting size of the beach. Include in your discussion, 1. an explanation of seasonal changes in the size of the beach 2. An explanation of longshore drift and 3. Two examples of how human activities can affect the size of the beach.
PRIMARY PRODUCTIVITY Why is the primary productivity in some ocean areas and low in others? In your answer: ● identify areas of the ocean have generally high productivity versus generally low productivity ● Evaluate the reasons for those differences in productivity based on factors such as the strength of the thermocline, seasonal changes in sunlight levels and presence of upwelling or downwelling.
ADAPTATIONS OF MARINE LIFE
One theme runs consistently to chapters 1415 to teach how to discuss the major types of pelagic and benthic animals. That theme is “adaptation”. Rain at sea in the general theme how marine animals are adapted to their environment using at least 3 specific examples. In other words from the many examples describing his two chapters pick three key adaptations (physical features and or behavior strategies) of marine animals that, to you, illustrate particularly well this theme of adaptation. Spread your examples around: don’t limit your examples to fish or cetaceans, but include at least one example from the benthic invertebrate animals.
