is sea level?
About 70% of
the Earth is covered by water in the form of oceans and seas. In
this lesson, you will begin a study of the surface of the oceans,
which is called sea level, and you will learn about different forces
that can affect it.
surface of the ocean can change dramatically over time. This lesson
will focus on short time period changes (hours, days, months), the
next lesson on ice volume will focus on much longer time period
changes. Here are some interesting photos to show you what we are
going to learn about: