Rock and ice atop the Mendenhall glacier outside of Juneau, Alaska
In Juneau, Alaska there are several groups that will - for a fee - ferry you via helicopter up over some extremely inhospitable-looking rugged mountain terrain and deposit you on top of a moving glacier to explore for a while. They're not moving so you'd notice, but most are; "flowing" along at a few feet per day, constantly being added to by snow falling, settling and compacting at their point of origin, century after century. In my case it was the Mendenhall glacier: a river of ice about 12 miles (19Km) long.
Like most people I'd long labored under the misinformation that glaciers were solid chunks of ice, but that's anything but the truth - actually they're more like gravel; small individual pieces of ice that grind along and move over, under and around each other as the mass is drawn downward by gravity. Nevertheless, when you're flying over it or seeing it from a distance it's still a formidable mass. It's the constant abrasions during their movement that create everything from the rounded valleys to the bits of ground rock that make a glacier sometimes appear "dirty".
Not being a fan of either heights or small, seemingly unstable aircraft there were some internal butterflies in flight before we lifted up off of the ground, but the amazing views and easy flying style of the pilot soon calmed my nerves. We gently banked and glided around for an overview and then spotted another group already on the ground. It's not a great picture, but you can make out the yellow tent in the upper left and the specks of people standing to the right of the photo's watermark below.
Once we were on the ground we could walk around and explore this icy wonderland, the small gravel-like bits crunching beneath the special cleated boots we were wearing. I haven't seen the movie "127 Hours" but the guide's warning kept me from venturing too near the edges of the crevasses. He said "I might go in after a human, but I won't risk my life for a camera. Hang onto yours!" - and I did.
You'll note that somewhat like a lake or an ocean the ice absorbs all of the other colors of the light spectrum and reflects only the blue... hence the color.
The bits of black sand and grit aside, the water was (naturally) ice cold, and so pure there was no discernible taste to it whatsoever.
Our scheduled time flew by, and all too soon it was time to again climb aboard our helicopter and make another scenic flight back to the starting point. This time we flew down to the face of the glacier, where the Mendenhall meets the water, for now. Regardless of your feelings about global warming this monster has receded 1.75 miles (2.82Km) since 1958.
If you ever have the chance to make a similar flight while traveling I'd suggest forgoing any other excursion options and doing it. It's something I'll never forget.