This is a photograph of Flattop Mountain, a popular peak near Anchorage, AK. The red line shows the equivalent volume of the 2009 Redoubt lava dome - 70 million cubic meters. This volume was calculated by USGS geologist Angie Diefenbach at the Cascades Volcano Observatory, using oblique photos taken by AVO geoscientists.
The original photograph of Flattop was taken by Jeff Medkeff, and is used here via Creative Commons. Doug Robbins added the Redoubt volume comparison.