Oceanography

  • Name the four branches of oceanography. Know the definitions.

    • Chemical Oceanography - studies the chemical composition and properties of seawater, how to extract certain chemicals from seawater, and the effects of pollutants

    • Geologic Oceanography - studies the structure of the seafloor and how it has changed through time; the creation of seafloor features, and the history of sediments deposited on it.

    • Physical Oceanography - study of the waves, tides, and currents; the ocean-atmosphere relationship that influences weather and climate, and the transmission of light and sound in the oceans

    • Biological Oceanography - studies the various oceanic life-forms and their relationships to one another, their relationships to the marine environment, and developing sustainable methods of harvesting seafood.

  • What are the subject areas studied in Oceanography?

    • Physics

    • Chemistry

    • Geography

    • Geology

    • Biology

    • Astronomy

  • Know the five oceans and characteristics of each.

    • Pacific

    • Indian

    • Atlantic

    • Antarctic

    • Arctic

  • Ocean vs. Sea

  • How did the Sargasso Sea get its name?

    • From the abundance of seaweed/algae found in it.

  • How much of the Earth’s surface is represented by oceans and marginal seas?

    • 71%

  • Define Salinity.

    • Total amount of solid material dissolved in water

    • Represented in parts per thousand

  • What is the main mineral in ocean water?

    • Sodium chloride, NaCl, also known as Halite or salt

  • In parts per thousand, what is the average Salinity of seawater?

    • 35%

  • Describe an area with low Salinity levels

    • Near equators; areas with heavy rainfall

  • Describe an area with high Salinity levels

    • Dry, hot, and landlocked regions

  • What happens to surface temperature with decreasing latitude

    • Increasing temperature

    • Inverse relationship

  • What factors is the density of ocean water dependent on?

    • Temperature

    • Ocean depth

    • Salinity

  • What conditions account for high density of ocean water?

    • Low temperature

    • High Salinity

    • Deep waters

  • What conditions account for low density of ocean water?

    • High temperature

    • Low Salinity

  • Define Bathymetry. What can it do?

    • Bathymetry - measurement of ocean depths and charting of the shape or topography of the ocean floor

    • Used to measure sea levels decreasing due to climate change

  • What does SONAR stand for? What does it do?

    • Sound Navigation and Ranging

    • Produces detailed views of the ocean floor

  • How do ocean trenches form?

    • When tectonic plates converge; compression

  • How do mid-ocean ridges form?

    • Seafloor spreading; tension

  • Name factor(s) that affect surface currents on the ocean

    • Trade winds

    • Westerlies

  • Name factor(s) that affect deep ocean currents

    • Differences among water density

      • Density variations caused by differences in temperature and salinity

  • Describe the movement of waves on the ocean

    • Back and forth - oscillation

  • What are the subtropical gyres?

    • Trade winds

    • Westerlies

  • What is the Pacific Garbage Patch?

    • 20 billion pounds of plastic

    • About the size of Texas

  • What is thermohaline circulation?

    • Deep ocean circulation

  • What is the cause of thermohaline circulation?

    • Density variations among water masses

  • How fast do the currents travel in the deep ocean circulation that creates a Global Conveyor Belt?

    • Nine miles a year

  • What causes coastal upwelling?

    • Rising of cold water from deep layers

  • Where does coastal upwelling usually occur?

    • West coasts of the continents

  • What causes wave movement?

    • Wind

  • What category of ocean life contains most of Earth’s biomass?

    • Floaters

      • Phytoplankton

      • Zooplankton

  • Name examples of Phytoplankton

    • Coccolithophores

    • Diatoms

    • Dinoflagellates

  • Name examples of Zooplankton

    • Squid larva

    • Copeod

    • Snail larva

    • Fish larva

    • Arrowworm

    • Foraminifers

    • Radiolarian

  • What are the swimmers known as?

    • Nekton

  • What are the bottom dwellers known as?

    • Benthos

  • What are the three ways we divide marine life zones?

    • Availability of sunlight

    • Distance from shore

    • Water depth

  • Why does the abyssal zone have cold, dark conditions and have little life?

    • 15,000 to 20,000 feet deep

  • What is a continental shelf?

    • A flat zone from the shore to the shelf break

    • Average width is 43 miles, but can go out to 930 miles

  • What are abyssal plains?

    • Some of the deepest, flattest parts of the Earth

    • Averages 15,000 to 20,000 feet deep

    • Found in Indian and Atlantic oceans

  • What are ocean trenches?

    • A deep valley on the ocean floor which is usually near the margins of continents.

    • Deepest part of the ocean with crushing high pressure, complete darkness, and near-freezing water temperatures

  • What is the mid-ocean ridge?

    • Longest mountain chain (46,000 miles total)

    • Average height is 1.5 miles

    • Average width is 620 miles

    • Covers 23% of the Earth’s surface

    • Forms from seafloor spreading