Sea Ice vs Glacial Ice

Antarctica is lacking many things - humans, trees, McDonalds (thank goodness). But one thing that there is no shortage of? Ice.

Ice, ice, everywhere you look from the flat pancake ice on the surface of the sea to the massive, majestic icebergs larger than your ship. It is beautiful and awe-inspiring. Who needs architects when the elements create these beauties naturally?

We were fortunate enough to have rock star Bob Gilmore as our onboard glaciologist. Bob is one of the scientists who has spearheaded the citizen science movement, giving you the ability to participate in the research efforts of the specialists on your cruise. For example, you may collect water samples and test for phytoplankton or survey the passing clouds. Bob gave compelling lectures on sea ice, glacial ice, and climate change during our expedition - some of the lectures I found most important and fascinating.

The most notable difference between the two types of ice is this:
Sea ice = Frozen ocean water. Sea ice grows, forms, and melts in salty ocean water and is free floating. Includes pancake ice and pack ice.
Glacial ice = Land ice or glaciers formed from fresh water. May be attached to land, grounded OR free floating (see icebergs, below).

So, what are icebergs? Icebergs are hunks of glaciers that have calved off and fallen into the sea. These are essentially freshwater ice sculptures floating in the salty ocean!

Why is sea ice so important? It may be localized to the polar regions, but sea ice moderates the entire globe's climate. Because of its bright, white, reflective surface, sea ice reflects about 80% of the sunlight that hits its surface right back into space, keeping temperatures in these regions very low. If sea ice continues to melt at the rate that it is, and there are fewer reflective surfaces to send the sun's rays back into space, more solar energy will be absorbed by the earth's surface, and the result will be a continually rising global temperature.

Changes in sea ice levels can also interrupt ocean circulation and currents, which moderate the global climate as well. And lastly, large amounts of sea ice limit the amount of moisture moving to the atmosphere, preventing strong storms from developing. The dwindling of sea ice is why we are seeing an increase in severe storm systems like hurricanes or typhoons worldwide.