Mt. Fitzherbert
USGS Update 2005-Mar-16 10:30
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 eastward.
Potential ash hazards to aviation: Under current eruptive conditions, small, short-lived explosions may produce ash clouds that exceed 30,000 feet in altitude. Ash from such events can travel 100 miles or more downwind.
Recent observations: Yesterday field crews got good views and thermal images of the growing lava dome. They found no major changes, but noted deposits of small warm flows of pulverized rock that had sloughed off the east side of the lava dome and onto the east arm of the glacier. A seismometer was slung by helicopter to the old lava dome and placed at the site of station SEP, which was destroyed in last week's explosion. The new seismometer is a different type than the old one, so signals on SEP Webicorder plots look different. Also, about 1 p.m. (PST) a crew reduced the gain setting on seismic station YEL, which makes the signals look smaller than on earlier YEL Webicorder plots.