National Geographic : 1918 Feb
0o Photograph by Robert F.Griggs THE LAVA PLUG OF NOVARUPTA FROM THE CRATER RIM "Novarupta apparently began with an explosive violence surpassed in this district only by Katmai itself. ...After explosive activity had ceased there was a slow extrusion of pasty lava from the vent. This has been pushed up until it forms agreat plug oflava. Itssurface iscovered with an indescribable confusion of fragments of all sizes, shapes, and colors. We could only guess how faritmight bethrough this mantle offrag ments to the still molten lava beneath."