September 8, 2012

Alaska - Bergy Bits and Growlers

Are you ready for a little lesson about bergy bits and growlers? No, I’m not talking gibberish. I’m talking about icebergs!

On our small boat cruise this past July through Alaska’s Inside Passage, we got to see some great examples of nature’s ice sculptures. Broken off from glaciers, these chunks can take on some amazing shapes as they melt. 

Can you spot some profiles of sea creatures in these photos?

"Growlers" are small chunks of floating ice that extend only about a meter above the water. When they melt, the trapped air escapes and sometimes sounds like an animal growl. "Bergy bits" are small icebergs that rise one to four meters out of the water. Also, a good rule of thumb for navigators is that only 10 to 20 percent of an iceberg is above the water. So one has to exercise caution to safely skirt around them!

Some of the compacted ice is a dazzling shade of blue. There are a couple of factors that create this color. First of all, the ice has been under enormous pressures for thousands of years. Most of the air and reflective surfaces have been eliminated from this pressure. So ambient light is primarily absorbed into the iceberg rather than reflected. Weaker wavelengths of light are filtered out. But the blue wavelength has enough energy to penetrate.

And the closer you get to an iceberg, the more the water takes on a chalky blue-green color. This hue comes from the amount of suspended glacier silt (soil and sediments) in the water.

And thanks to some pretty photos, that’s your science lesson for the day!


  1. thank you, donna! i will promptly forget about 90% of that. :)

  2. Fascinating and while I may remember that some of the icebergs are blue, I'll never remember why. That's okay, I may remember that it was either here or at Judy's Front Porch because she talked about it a little bit recently. They are beautiful. I think someone's giving someone the bunny ears in that first character study.

  3. Thanks for the science lesson, Donna! Did you hear any "growling" while you were taking those photographs?

  4. Oh Donna! These are SO beautiful I can't imagine being there and so close!
    Love it...

  5. Can I just say one more time this is definitely on our list of "go to's" your photos are always so perfect! I also want to thank you for all the sweet comments you've left for me recently. As always, very appreciated.

  6. That is so interesting. They look rather imposing as you see them cruising by! But you got great photos and I learned something new!

  7. Bergy Bits and Growlers, I love it! Sounds like something from Harry Potter.
    As always Donna your photos are so crisp and clear I feel like I am there. I wish I could hear them growl.

  8. My goodness! That was SO interesting! I love the blue hues in the ice, and the different shapes are cool too. You could have been a science teacher, girl! :-)


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