Jan 10 2008
Mount St. Helens Daily Update for 1/10/08
Current Mount St. Helens status from CVO:
Thursday, January 10, 2008 11:30 PST (Thursday, January 10, 2008 19:30 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 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: Small, spotty earthquakes jostled some near-crater seismometers for about an hour this morning, coincident with a small tilt episode (deflation-inflation) recorded by our NDM tiltmeter. These events, related to dome growth, are “instrumental” in the sense that they are too small to be recognized, even if an frigid observer had been onsite in the crater’s blowing snow. Yesterday’s M 6.3 earthquake (http://earthquake.usgs.gov/eqcenter/recenteqsus/) 250 km off the central Oregon coast showed nicely on the Mount St. Helens seismic network but was too distant to be felt and has had no known effect on the eruption.
