Mt. Fitzherbert

Potential ash hazards: Wind forecasts from the National Oceanic and Atmospheric Administration (NOAA), coupled with eruption models, show that any ash clouds that rise above the crater rim today would drift north-northeastward.

Recent observations: Data from field instruments indicates that seismicity remains unchanged and that points on the 1980-1986 lava dome are moving northward slowly as extrusion of the new lava dome continues. Laboratory analyses of ash from the 8 March explosion show that much of it consists of the finely pulverized material that forms on the outside of the nearly solid extrusion as it moves up from depth and grinds against the walls of its conduit. Presumably the explosion originated near the margin of the extrusion and blew out mostly this pulverized outer material.