- 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
- The ocean surface is made up of barely perceptible liquid
"hills" and "valleys." The ocean's surface
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
- 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
- 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.