The pumice plain 30 years post-eruption
2009 view of the plain on the north side of St Helens. That flat surface was created when pumice-rich flows filled the irregular topography left by the debris avalanche.Vegetation is now well established, but note the rapid incision of the streams (indicated by the steep banks in non-cohesive material).
Photo by James Maynard © 2009 - free use with attribution