About our authors Robert W. Christopherson attended California State University-Chico for his undergraduate work and received his Masters in Geography from Miami University-Oxford, Ohio. Geosystems evolved out of his teaching notes and was his graduate thesis: this is his life's work. He founded the geography program of American River College faculty. His wife Bobbé is his principal photographer and has provided more than 300 exclusive photos for each of his books. Together they have completed nine polar expeditions (most recently in spring 2010). They attended the 2004 Arctic Climate Impact Symposium in Reykjavik, Iceland to acquire photo and video coverage and research. Robert is the recipient of numerous awards, including the 1998 and 2005 Text and Academic Authors Association Textbook Award for Geosystems and Elemental Geosystems, 4th Edition, respectively. He was selected by American River College students as "Teacher of the Year" and received the American River College Patrons Award. Robert received the 1999 Distinguished Teaching Achievement Award from the National Council for Geographic Education and the Outstanding Educator Award from the California Geographical Society in 1997. The Text and Academic Authors Association presented him with its Presidents' Award in 2005. Amongst many other things, Robert has been deeply involved in the development of Pearson's Geoscience Animation Library, and he led the editorial board of Rand McNally's Goode's World Atlas, 22nd Edition. Ginger H. Birkeland received her undergraduate degree from the University of Colorado, Boulder, and her M.A. and PhD in Geography from Arizona State University, with a focus in fluvial geomorphology. She taught physical geography at Montana State University and summer field courses at the Indiana University Geologic Field Station in Montana. Ginger worked as a professional river guide for 17 years on the Colorado River in Grand Canyon, as well as on rivers in Australia and throughout the U.S. West. She also worked as a geomorphology consultant on several government-funded projects, including the Truckee River Recovery Plan in California and Nevada. She has worked as a coauthor with Robert Christopherson on Geosystems and Elemental Geosystems since 2010.