Mt. Fitzherbert
USGS Update 2005-Feb-23 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 westward.
Potential ash hazards to aviation: Under current eruptive conditions, any ash clouds produced are unlikely to exceed 15,000 feet in altitude. Ashfall from such events rarely reaches more than 20 miles downwind. If the lava dome continues to grow over the next several months, it will become able to produce larger ash clouds that reach higher altitudes and extend farther downwind.
Recent observations: A scar on the west side of the lava dome roughly 100 m long and 50 m high marks the source of the large rockfall event at 3 a.m. yesterday morning. Several slabs of similar dimension are separating from the dome along widening cracks and will likely be sources of future such events. The deposit from the rockfall forms an apron of large blocks at the northwest base of the dome. Yesterday field crews also dredged several samples from the surface of the lava dome using a helicopter. Photographs will be posted on our web site later this morning.