Mt. Fitzherbert

Summary The pause in lava dome growth continues, and all our monitoring instruments show trifling or nil volcanic-related activity. This pause, which began in late January 2008, was recognized by absence of measurable growth among successive fixed-camera images, nearly quiescent seismicity, and the absence of tilt signals that might characterize extrusion of lava from the conduit.

We continue to monitor closely for evidence of renewed extrusion or other activity. The new lava dome remains hot in places; thus, it is capable of producing hot avalanches or small steam explosions that could cause hazardous conditions in and around the crater. Sudden melting of snow and ice could send small lahars onto the Pumice Plain and perhaps down the Toutle River as far as the Sediment Retention Structure (SRS). Ash clouds from explosions could affect aircraft.

Recent Observations: On a daily basis, a small steam plume rises above the active spine but usually dissipates before reaching crater-rim height. Under optimal atmospheric conditions this plume may ascend above the rim and be visible to residents and travelers in southwest Washington and northwest Oregon. This morning a small lenticular cloud formed above the volcano, owing to a changing weather system.

This past week field crews took advantage of good weather to repair a GPS antenna at Johnston Ridge Observatory, improve a radio connection for data transmission from Coldwater Ridge visitor center, and replace a bent antenna at one of our voice-communication repeater sites.

For the past month, locatable earthquakes at Mount St. Helens have been fewer than one per day, all smaller than magnitude 2. Ground tilt measurements show an overall sluggish subsidence in the area of the new dome. A GPS receiver on the active spine settles about 2 cm daily on a southward path.

Posted by Raoul Ortega at 10:32 | Permalink

Recent observations: Seismicity and ground-tilt remain at very low levels and examination of recent photographs from a remote camera on the crater rim confirms no recent detectable growth of the lava dome.

Posted by Raoul Ortega at 12:53 | Permalink

• Mount St. Helens decides it's time to take a breather 2008-Feb-22 00:00 from The Seattle Times

  After more than three years of nonstop eruption, the Energizer bunny that is Mount St. Helens appears to have run out of steam — at least for now.

  U.S. Geological Survey scientists say the growth of a new lava dome, which began with an explosive outburst in October 2004, has slowed to a halt.

  "We're calling it a pause," said Willie Scott, a volcanologist at the USGS Cascades Volcano Observatory in Vancouver, Wash. "We really don't know if it's going to start up again."

Posted by Raoul Ortega at 00:33 | Permalink

Current Volcanic- Alert Level Advisory; Aviation Color Code Yellow: Growth of the new lava dome inside the crater of Mount St. Helens, which began in October 2004, appears to have paused during the past month. Therefore, we are lowering the alert level from Watch to Advisory and the aviation color code from Orange to Yellow, which signifies that volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase. The rate of lava extrusion as determined by repeated aerial photography has been declining since late 2004, and other indicators of eruptive activity have also declined significantly. Comparison of photographs taken by remote cameras between late January and mid-February 2008 shows no evidence of extrusion. In addition, very few earthquakes have been recorded since late January, gas emissions are barely detectable, and daily ground-tilt events have stopped. These changes may only reflect a temporary pause in the eruption. The new lava dome remains hot in places and capable of producing hot avalanches or small steam explosions that could cause hazardous conditions in and around the crater. Sudden melting of snow and ice or intense rainfall could send small lahars onto the Pumice Plain and perhaps down the Toutle River as far as the Sediment Retention Structure (SRS). Ash clouds from explosions could affect aircraft. Until conditions warrant a change, Cascades Volcano Observatory will issue weekly updates on Fridays, rather than our current daily updates.

Posted by Raoul Ortega at 23:54 | Permalink

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 north-northeastward to northeastward.

ecent observations: Seismicity and ground deformation remain at very low levels. The small seismic signals recorded only on station VALT are glacier quakes caused by movement of nearby glacier and boulders rolling off its steep snout.

Posted by Raoul Ortega at 08:44 | Permalink

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 north to north-northeast.

Recent observations: Gelid Mount St. Helens is visible under clear and sunny skies as viewed from the USFS VolcanoCam at Johnston Ridge Observatory. Seismicity remains at low levels, similar to the past several days.

Posted by Raoul Ortega at 11:28 | Permalink

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 northwestward this morning shifting to north to northeastward by afternoon.

Recent observations: Mount St. Helens can again be seen under clear and sunny skies from the USFS VolcanoCam at Johnston Ridge Observatory. Seismicity remains very low.

Posted by Raoul Ortega at 12:00 | Permalink

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 southwestward this morning, shifting to southeastward by afternoon.

Recent observations: Snowy Mount St. Helens is clearly visible this morning in views from the USFS VolcanoCam at Johnston Ridge Observatory. Seismicity remains very low.

Posted by Raoul Ortega at 11:21 | Permalink

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.

Recent observations: No changes. Seismicity remains very low, and the crater is obscured by clouds this morning. Crews were in the field yesterday repairing and positioning monitoring instruments as well as measuring gas emissions from the volcano.

Posted by Raoul Ortega at 10:37 | Permalink

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 SE this morning, but more directly E this afternoon.

Recent observations: Seismicity at the volcano continues to be very low. It is a clear sunny day there again this morning. Yesterday, helicopter-supported field crews were able to complete some maintenance at instrument sites, and more work is planned for today. A flight to monitor volcanic gases over the volcano is also planned for today.

Posted by Raoul Ortega at 11:02 | Permalink

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 SSW this morning, shifting to S this afternoon.

Recent observations: It is clear and sunny at the volcano this morning, although no promineant vapor plume is visible at the moment. Seismicity remains very low.

Posted by Raoul Ortega at 11:20 | Permalink

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 SE in the morning, shifting to S in the afternoon.

Recent observations: No changes. Seismicity remains very low, and the crater is obscured by clouds this morning.

Posted by Raoul Ortega at 10:16 | Permalink

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 ESE this morning, shifting slightly to E this afternoon.

Recent observations: Seismicity continues to be very quiet. The crater is visible this morning from Johnston Ridge.

Posted by Raoul Ortega at 10:31 | Permalink

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 east-southeast.

Recent observations: The St. Helens crater can be faintly seen through light precipitation this morning, allowing us to bear witness to the wintry landscape produced by the intense snowfalls of the last several weeks. Despite the storms many instruments continue to function, allowing us to report that seismicity levels remain very low.

Posted by Raoul Ortega at 13:20 | Permalink

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 to the northeast and east early in the day, and shift toward the southeast later.

Recent observations: Yesterday, for the first time in many days, partially clearing skies afforded glimpses of Mount St. Helens, heavily draped in new snow. Mantling clouds and precipitation have returned this morning, and several inches of additional snow are expected today at crater elevations. Seismicity at Mount St. Helens remains very low.

Posted by Raoul Ortega at 11:33 | Permalink

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 east-southeast today, shifting to northeasterly by this evening.

Recent observations: Snowfall is tapering off at St. Helens this morning, but a resultant snowdrift has entirely blocked crater views via the USFS webcam at the Johnston Ridge Observatory. Up to a foot of additional snow is forecast to fall through tomorrow, and more snow is in the forecast for next week. Despite such accumulations, enough seismometer sites have their antennas poking above the snowpack for us to say with certainty that seismicity levels continue to be very low.

Posted by Raoul Ortega at 09:53 | Permalink

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 to the east and southeast.

Recent observations: Mount St. Helens continues to be pummeled by winter storms, with two to three feet of additional snow accumulation expected today. Precipitation may change to rain tomorrow, and this change could trigger snow avalanches that produce seismic signals. Otherwise, seismicity at Mount St. Helens remains very low.

Posted by Raoul Ortega at 10:53 | Permalink

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 to the east-southeast.

Recent observations: Yet another in a series of storms is obscuring views of Mount St. Helens this morning. The weather forecast calls for two-three feet of additional snow accumulation through tomorrow, with inclement weather continuing through the weekend. An impressive snow drift can be seen in the foreground on the USFS webcam, a drift that has been increasing in size over the last several days. The growing snow drift has been the most notable visible sign of change at St. Helens, as remote cameras in the crater, although functioning, are buried or encased in ice and are thus unable to provide information on dome growth. Seismicity levels remain very low.

Posted by Raoul Ortega at 12:24 | Permalink

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 to the east and southeast.

Recent observations: Mount St. Helens remains shrouded in clouds this morning. Generally stormy weather continues in the region, and more snowfall is expected today and tonight. Seismicity at the volcano remains very low. While most instrument sites continue to function, several have experienced transmission problems over the last few days, presumably due to snow/ice accumulation.

Posted by Raoul Ortega at 11:57 | Permalink

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 to the southeast, shifting to easterly by this evening.

Recent observations: Views of St. Helens this morning are obscured by clouds, snow, and ice from yet another winter storm. While most instrument sites continue to function, several have experienced transmission problems over the last few days, presumably due to snow/ice accumulation. Seismicity levels remain low.

Posted by Raoul Ortega at 10:53 | Permalink

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 south to southeast.

Recent observations: A few moments of sunshine in the Portland/Vancouver area on Sunday raised false hopes. We are back to cloud cover, and the volcano is completely obscured. Seismicity remains at the low level of recent weeks.

Posted by Raoul Ortega at 11:26 | Permalink

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 to the northeast.

Recent observations: We are having a brief respite from precipitation in the Portland/Vancouver area this morning, but the gray skies remain, and the volcano is completely obscured. Snowpacks in the Cascades are at record depths for the date, according to news reports. Seismicity at the volcano remains at the low level characteristic of recent weeks.

Posted by Raoul Ortega at 14:03 | Permalink

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 east to southeast.

Recent observations: Continuing winter storms completely obscure the volcano, where heavy snow is accumulating presently. Seismicity remains at the low level of recent weeks.

Posted by Raoul Ortega at 13:11 | Permalink

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 to the southeast.

Recent observations: Our stormy weather continues unabated, completely obscuring the volcano. Seismic activity remains at the low level of recent weeks.

Posted by Raoul Ortega at 15:31 | Permalink