My wife and I had joined a group of hikers for a day of ice trekking on the Perito Moreno Glacier. Just as we finished lunch, I climbed up to a high point beside this gorgeous blue meltwater pool to get a composition showing the vast ice field in the distance, then waited for the group to catch up. I took this shot as the last person in the group came into vew.

During spring and summer, the snow on top of the glacier melts, and water collects into pools on the surface. The blue color is caused by the dense ice underneath absorbing all the red and yellow wavelengths of the sunlight, reflecting only the blue portion of the spectrum. Due to global warming, glaciers around the world are shrinking and disappearing. This particular glacier is one of the few left on the planet that is still growning in size.