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Topic: Properties of the Ocean

Theme: Interactions

Key Concepts:

Seafloor and Ocean Surface

  • Slumping of large masses of ocean sediment disturbs the overlying surface water and produces a series of flat, long-period waves, known as tsunamis.
  • Tsunamis in the open ocean usually pose no threat because of the depth to the ocean floor. As tsunamis approach the shore where the depth of the ocean decreases, the waves can reach great heights thus becoming very destructive.
  • The ocean surface is made up of barely perceptible liquid "hills" and "valleys." The ocean's surface topography is indicative of its submarine (underwater) topography/bathymetry.

Ocean and Atmosphere

  • The oceans contain many times more heat energy than does the atmosphere because:
    • Water is denser than air and the total mass of ocean water is 200 times the total mass of air in the atmosphere.
    • Water has a much higher heat capacity per unit mass than air or the rocks and soil of the land.
  • The oceans (which contain over 97% of the world's water) are in contact with and can exchange heat and water vapor with the atmosphere over more than 70% of Earth's surface.
  • The atmosphere is separated into three distinct zones:
    • the troposphere,
    • the stratosphere, and
    • the mesosphere
  • In the troposphere, air masses move continuously, both vertically and horizontally. The movements are mostly caused by changes in density as water vapor is added to or removed from the air mass, and they control Earth's weather and climate.
  • Heat transfer from the oceans to the atmosphere causes atmospheric convection.

Ocean-Land-Atmosphere

  • Earth's surface heats by day from solar radiation and cools at night, as the heat is lost.
  • Because of water's high latent heat, the ocean surface water temperature vaires little in this daily cycle. The land temperature, however, varies more.
  • During the day the land heats. As the air warmed by the heat of the land rises, cooler air from over the ocean replaces it, creating a "sea breeze."
  • At night the land cools rapidly, which creates a "land breeze" that flows seaward to displace warmer, less dense air over the ocean.