This is picture is a composite image called "The Essence of Imagination," marketed by Successories, the "premiere source for motivational media."

This image was produced in 1999 by Ralph A. Clevenger, a professional nature and underwater photographer who is also a member of the faculty of the Brooks Institute of Photography in Santa Barbara, California. As Mr. Clevenger explained, this image is not a single photograph but a composite of four different photographs (not all taken in the same place):

The iceberg image is a digital composite that I designed to illustrate the concept of "what you see is not necessarily what you get." As an underwater photographer I knew that my "vision" of what a big iceberg looks like was impossible to get in reality so I had to create it. The image exists in nature but due to water visibility is not possible to capture on film.

There are 4 separate images involved; the sky, the background, the top iceberg (shot in Antarctica), and the underwater iceberg (shot above water in Alaska and flipped in the final composite.)

Source: Snopes.com