The ever-expanding 500-foot-high lava dome in Mount St. Helens' crater is a towering pile of rubble on Aug. 2, 2005, following eight magnitude 3 earthquakes in the previous week. The quakes, slightly larger than normal, shook loose parts of steeply pitched fins running atop the structure. Scientists say there are no signs, however, of an imminent eruption. Mount Hood looms to the south. (AP Photo/The Oregonian, Bruce Ely)

At this rate, how long will it take for the dome to fill the crater and regain the mountain's previous height? Probably won't occur in our lifetimes, but it is something to monitor over the next few centuries.