- Key Concepts:
- Differences in salinity of ocean surface waters are
- variations in the rate of ocean surface water evaporation,
- variations in the rate of freshwater input from rainfall
and land runoff, and
- in limited areas by upwelling and
- Salinity distribution is related to evaporation-precipitation
cycle variations at different latitudes. When seawater freezes, salinity
increases in the remaining water. Regional variations in salinity exist
- Salinity is generally higher in the sub-tropical latitudes
that are remote from land.
- Salinity is generally lower at the equator, in polar
and sub-polar regions, and near continents.
- Eustatic sea level changes are caused by changes of
volume of ocean water as a result of extensive formation or melting of
icecaps and glaciers.
- Eustatic changes of sea level take place simultaneously
and uniformly throughout the world. Eustatic equilibrium (balance) is
easily and quickly attainable.
- Human civilization has emerged during a long period
of relatively stable sea level.
- The predicted greenhouse warming of the planet could
cause higher-than-average global temperatures, which, in turn, would cause
the current polar ice sheets and glaciers to melt and sea level to rise.
- Seafloor Topography
- Tectonic processes (such as subduction and seafloor
spreading) and sedimentation are the principal agents that shape and change
the seafloor topography over time. Changes in climate can also affect