USGS Update 2005-Jun-10 09:45
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.
Recent observations: Yesterday’s gas-sensing experiment was partly successful. After scientists spent two hours hauling equipment and setting it up on the east crater rim in clear conditions, the crater clouded in and remained so for much of the day. Scientists were able to get only one preliminary set of data with the new infrared spectrometer. The results were encouraging and showed that the technique will work, but they weren’t sufficient to provide quantitative measurement of gases. The instrument has to go back to our Hawaiian Volcano Observatory for awhile, but we will retry the experiment later in the summer. Concurrent measurements of gases using our usual airborne techniques were likewise foiled by weather. Good photographs of the new lava dome taken yesterday morning will be available on our web site today.
Growth of the new lava dome inside the crater of Mount St. Helens continues, accompanied by low rates of seismicity, low emissions of steam and volcanic gases, and minor production of ash. During such eruptions, episodic changes in the level of activity can occur over days to months. The eruption could also intensify suddenly or with little warning and produce explosions that cause hazardous conditions within several miles of the crater and farther downwind. Small lahars could suddenly descend the Toutle River if triggered by heavy rain or by interaction of hot rocks with snow and ice. These lahars pose a negligible hazard below the Sediment Retention Structure (SRS) but could pose a hazard along the river channel upstream.
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.
The U.S. Geological Survey and the University of Washington continue to monitor the situation closely and will issue additional updates and changes in alert level as warranted.
My intent with this page is to provide a clearning house for links to the current activity at Mt.St.Helens. Please send me any links of interest that you may come across, whether for permanent sites or for news reports. I'm not going to be able to do this all alone and all help will be appreciated.
(Disclaimer I have no association with anyone or any organization, and speak only for myself. Links and quotes are provided for information only.)