America’s Volcanoes

Current Mount St. Helens status from CVO:

Friday, August 31, 2007 09:25 PDT (Friday, August 31, 2007 16:25 UTC)

MOUNT ST. HELENS UPDATE
Current Volcanic- Alert Level WATCH; Aviation Color Code ORANGE: 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, changes in the level of activity can occur over days to months. The eruption could 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: Wind forecasts from the National Oceanic and Atmospheric Administration (NOAA), coupled with eruption models, show that any ash clouds rising above the crater rim today would drift northeast.

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: Under partly sunny skies, a steam plume can be seen rising from the new dome and drifting northeastward above the crater rim this morning. There are no significant changes in the on-going eruptive condition. Very low-level seismicity punctuated by sporadic rock falls are indicative of continued lava dome growth.

Trackback URI | Comments RSS