1. Erosion

2. Glacier
Photograph of Wolverine Glacier: U.S. Geological Survey

3. Glaciers Glacier at the head of Canon Fiord, Ellesmere Island, Canada.
Glacier terminus: National Snow and Ice Data Center

4. Glaciers
McCall Glacier, photographed by Austin S. Post in 1958 (left) and by Matt Nolan in 2003 (right).
From the Online glacier photograph database. Boulder, Colorado USA: National Snow and Ice
Data Center/World Data Center for Glaciology. Digital media.

5. Glaciers
Muir Glacier, photographed by William O. Field on 13 August 1941 (left) and
by Bruce F. Molnia on 31 August 2004 (right). From the Online glacier photograph database.
Boulder, Colorado USA: National Snow and Ice Data Center/World Data Center for Glaciology.
Digital media.

6. Glaciers
Qori Kalis Glacier, photographed by Lonnie G. Thompson (1978 and 2004), Byrd Polar
Research Center, The Ohio State University. From the Online glacier photograph database.
Boulder, Colorado USA: National Snow and Ice Data Center/World Data Center for Glaciology.
Digital media.

7. Windy day at Ft. Irwin. Photo by Tony Troxler, USGS.
It’s a Force, Of Course
Windy day at Ft. Irwin. Photo by Tony Troxler, USGS.

8. It’s a Force, Of Course
Kelso Dunes in the Mojave National Preserve. Photo by David Miller, USGS.

9. Guadalupe Mountains National Park. View of El Capitan, USGS.
It’s a Force, Of Course
Guadalupe Mountains National Park. View of El Capitan, USGS.

10. Mushroom Rock. Theories of formation include wind erosion. USGS.
It’s a Force, Of Course
Mushroom Rock. Theories of formation include wind erosion. USGS.

11. Before and after pictures, Cowells Beach. USGS.
It’s a Force, Of Course
Before and after pictures, Cowells Beach. USGS.

12. It’s a Force, Of Course
Floodwaters. USGS.

13. San Antonio. Cibolo Creek. Bob McMillan FEMA Photo
It’s a Force, Of Course
San Antonio. Cibolo Creek. Bob McMillan FEMA Photo

14. It’s a Force, Of Course
Soil erosion. USDA

15. It’s a Force, Of Course
Grand Canyon. USGS