Today,
icebergs and sea ice are found in the world's coldest oceans of
the Antarctic and Arctic, and glaciers are found at the tops of
the highest mountains. But ice on the continents and around the
polar seas has grown and retreated many times in the last few million
years. Start interactive »
Climate Related Hot Topics
Going
vertical: Gauging ocean overturn rates
Water in the ocean has different ages at different depths. Scientists can determine
these ages, and find out how long water takes to circulate through the entire
ocean and then come back to the surface. Learn
more »
Dating
corals, knowing the ocean
Coral skeletons record the age of the coral, as well as the age of the water
in which they grow. Using radioactive decay dating techniques on fossil, scientists
can tease this information apart. Learn
more »
Today,
icebergs and sea ice are found in the world's coldest oceans of
the Antarctic and Arctic, and glaciers are found at the tops of
the highest mountains. But ice on the continents and around the
polar seas has grown and retreated many times in the last few million
years. 
