Thursday, February 16, 2017

Icebergs...Glaciers and The Blues

It is early in the season to be exploring the Passage (even virtually) and ice still litters these waters in frozen chunks.

From glacier that run to the edge

to island sized icebergs that float along

Some of this ice still around from 11,000 years ago (during the last Ice Age).

The various shades of blue caused not by the sky or the surrounding Pacific Ocean...but instead by the gases in the ice and extreme compression flattening and enlarging the crystals themselves. They can effectively absorb every colour on the spectrum except blue. When the light is refracted the reflection we see and perceive is blue.

And the Alaskan Ice defines blue. From a milky agate blue to a deep turquoise...and seemingly every shade in between. Some as light as the lightest blue topaz. Most striated with bands from centuries and centuries of compression and growth.

Included in today's ice tour The Sawyer Glacier

The Hubbard Glacier

And Tracy Arm Fijord

Occasionally with a thunderous crack an iceberg or glacier will calf. This is known as "white thunder" and as you can  imagine is very loud. A great part of itself breaking away to fall into the water below

Video (with sound) of Calving.

and why you really don't want to be close to them when it happens 

Off to warm up with Tea and Scones.

More anon...