Bob Anderson is chair of the department of Geological Sciences at the University of Colorado Boulder.  He is a geomorphologist who has studied many diverse aspects of the landscape, focusing recently on Alpine and Arctic landscapes in which ice plays a prominent role.  It was his sense of awe and aesthetic appreciation of patterns in nature that drew him into the field.
In the podcast he uses the Sierras as a classic example of how the nature of the bedrock shapes landscape, and explains how the use of cosmogenic radionuclides has revolutionized our ability to uncover the timing of the processes shaping the Earth’s surface.
Bob Anderson is also an accomplished photographer.  Go to geologybites.com to see some of his pictures as well as other images that illustrate the material he talks about.