Mt. Fitzherbert

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.

Recent observations: Clouds obscure the volcano this morning. Small periodic earthquakes at the volcano continue and indicate that dome extrusion continues. Some seismic stations are operating only intermittently because of heavy snow in the crater and on the upper parts of the volcano.

Posted by Raoul Ortega at 12:28 | 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 early today would drift southeast, but later today would variably drift southeast to northeast.

Recent observations: The volcano is clear and windy this morning. Small periodic earthquakes at the volcano continue and indicate that dome extrusion continues. Dome extrusion is accompanied periodically by rock-fall events. Some seismic stations are operating only intermittently because of heavy snow in the crater and on the upper parts of the volcano.

Posted by Raoul Ortega at 12:05 | Permalink

Aerial views taken on 2006-Nov-25

Recent observations: Mount St. Helens is obscured by clouds this morning. Small periodic earthquakes at the mountain indicate that the volcano continues to erupt. Dome extrusion is accompained periodically by rock-fall events.

Posted by Raoul Ortega at 10:41 | 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: The volcano is shrouded in snow clouds this morning, obscuring views from the VolcanoCam at Johnston Ridge Observatory. Remote monitoring instruments indicate that the eruption continues with low levels of background seismicity, episodically occurring M 1.5-2.5 events, and occasional larger quakes. No significant changes in eruptive activity have been observed in the past 24 hours.

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 northeastward.

Recent observations: Clouds, snow, and ice preclude visual observations of the volcano this morning. Remote monitoring instruments indicate that the eruption is continuing with low levels of seismicity and occasional larger quakes. No significant changes in eruptive activity have been noted in the last 24 hours.

Posted by Raoul Ortega at 11:10 | 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 southeastward.

Recent observations: The snow-covered flanks of the volcano are visible this morning in icicle-impeded views from the VolcanoCam at Johnston Ridge Observatory. Remote monitoring instruments indicate that the eruption continues with low levels of background seismicity, episodically occurring M 1.5-2.5 events, and occasional larger quakes. Yesterday at 1:45 PM PST (21:45 UTC) a M 2.9 earthquake occurred. No significant changes in eruptive activity have been observed in the past 24 hours.

Posted by Raoul Ortega at 10:20 | Permalink

• Dynamics of seismogenic volcanic extrusion at Mount St Helens in 2004–05 2006-Nov-23 Nature

  Abstract: The 2004–05 eruption of Mount St Helens exhibited sustained, near-equilibrium behaviour characterized by relatively steady extrusion of a solid dacite plug and nearly periodic shallow earthquakes. Here we present a diverse data set to support our hypothesis that these earthquakes resulted from stick-slip motion along the margins of the plug as it was forced incrementally upwards by ascending, solidifying, gas-poor magma. We formalize this hypothesis with a dynamical model that reveals a strong analogy between behaviour of the magma–plug system and that of a variably damped oscillator. Modelled stick-slip oscillations have properties that help constrain the balance of forces governing the earthquakes and eruption, and they imply that magma pressure never deviated much from the steady equilibrium pressure. We infer that the volcano was probably poised in a near-eruptive equilibrium state long before the onset of the 2004–05 eruption.

Posted by Raoul Ortega at 21:48 | 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: Clouds and snowfall preclude visual observations of the volcano this morning. Remote monitoring instruments indicate that the eruption continues with M 1.5-2.5 earthquakes occurring episodically amidst lower background seismicity.

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 eastward.

Recent observations: Stormy weather remains in the region and clouds obscure views of the volcano. Seismicity has declined somewhat over the past few weeks, but M 1.5-2.5 earthquakes continue to occur episodically amidst a background of smaller quakes.

Posted by Raoul Ortega at 11:13 | 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 northeast.

Recent observations: Stormy weather has moved back into the region and clouds obscure views of the volcano. Seismicity has declined somewhat over the past two weeks, but M 1.5-2.5 earthquakes continue to occur episodically amidst a background of smaller quakes.

Posted by Raoul Ortega at 10:57 | Permalink

Aerial views taken on 2006-Nov-17

Recent observations: Views from aircraft over the past weekend and from an automated camera in the crater show that the active lava spine is continuing to extrude. Seismicity has declined somewhat over the past two weeks, but M 1.5-2.5 earthquakes continue to occur episodically amidst a background of smaller quakes.

Posted by Raoul Ortega at 10:56 | Permalink

Recent remote views

Recent observations: Though skies are partly cloudy this morning, views of the volcano are reasonably good. Recent storms have deposited snow well below the level of the crater. Hence, if views of the crater become clearer it should be relatively easy to identify the warm, actively growing spine. Seismicity has not changed in the past 24 hours; earthquakes in the M1.5-2.5 range continue to occur episodically amidst the background of smaller quakes.

Posted by Raoul Ortega at 12:07 | 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 northeastward.

Recent observations: Stormy weather has moved back into the region and clouds obscure views of the volcano. At 8:20pm local time Saturday evening, a M3.4 occurred at the mountain. This earthquake, the largest to have occurred in over two weeks, may be associated with crumbling of part of the actively growing spine. Such episodic large quakes, which occur amidst the constant background of very small earthquakes, are not unusual for the type of eruptive activity that is ongoing.

Posted by Raoul Ortega at 12:12 | 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 eastward.

Recent observations: Temporary outage of the USFS VolcanoCam thwarts remote views of the volcano this morning, but valley fog suggests that the mountain is likely clear. Seismic patterns remain the same as in the past few days, with episodic M1.5 to M2.5 earthquakes punctuating the constant background of very small earthquakes. These slightly larger quakes may be associated with rockfalls from the growing spine, and are par for the course under the current style of eruption.

Posted by Raoul Ortega at 11:04 | 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 early in the day, and east-northeastward later in the day.

Recent observations: The volcano is clear today above the valley fog, and the crater is cloaked in new snow. The lava dome continues to extrude, and seismicity continues much as it has over the past several days, with occasional larger earthquakes (M2+)punctuating the constant background of very small earthquakes.

Posted by Raoul Ortega at 10:55 | 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.

Recent observations: The Mount St. Helens crater is intermittently visible from the JRO VolcanoCam, amidst sun breaks through mostly cloudy conditions this morning. The snow level is at ~2500 ft. elevation and some precipitation is expected. A steady low-level seismic signal with occasional small (less than M. 2) earthquakes, emanating from shallow depths within the crater, indicate continued eruption and dome-growth.

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 northeast.

Recent observations: This mornings remote camera views of Mount St. Helens activity are completely obscured by inclement weather which is expected to persist throughout the day, with rain and strong winds (snow level is at ~8000 ft. elevation). Persistent patterns of low-level seismicity indicate that dacite extrusion and dome-building within the crater continues in a relatively quiescent fashion.

Posted by Raoul Ortega at 10:35 | 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 this morning and southeastward later in the day.

Recent observations: Mount St. Helens is mostly cloud covered this morning and partly sunny skies are forecast for this afternoon. The snow level is down to 3000 ft. elevation. As indicated by real-time siesmic and deformation data transmitted from the volcano, the eruption continues without signficant change.

Posted by Raoul Ortega at 10:30 | 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: Stormy weather continues to preclude views of the volcano. Our field instruments indicate that there have been no changes in the behavior of the eruption in the past 24 hours.

Posted by Raoul Ortega at 15:28 | 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 mostly to the east this morning, shifting to the northeast this afternoon.

Recent observations: Low levels of seismic activity and slow displacements of crater GPS stations indicate that the eruption is continuing in the same mode as recent months. Views of the volcano today are mostly obscured by clouds. Rain and snow are expected later today, with strong winds arriving tonight.

Posted by Raoul Ortega at 12:03 | 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 principally to the east.

Recent observations: Seismic and geodetic data indicate that the eruption of Mount St. Helens continues in the same quiescent fashion as in recent months. Partly clearing skies have afforded glimpses of the lower flanks of the volcano from Johnston Ridge Observatory this morning. Overnight, new snow accumulated at elevations above about 3000 feet, and more snow is expected to accumulate today and tonight.

Posted by Raoul Ortega at 19:24 | 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 eastward to southeastward.

Recent observations: Mount St. Helens received a temporary respite from bad weather today. The snow-covered lower half of the mountain and upper North Fork Toutle River Valley are visible from the Johnston Ridge Observatory below the cloud cover. Storm-related noise on the seismic records is also gone now. Lava extrusion is presumed to be continuing.

Posted by Raoul Ortega at 10:56 | 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 northeast this morning, shifting to the northeast and north this afternoon.

Recent observations: Incoming data indicate that the ongoing eruption, characterized by solid-state lava extrusion and low levels of seismicity, continues in the same mode as in recent months. The moisture-laden Pacific storm that has drenched Mount St. Helens and the surrounding region the past few days has abated, and the volcano is partly visible from Johnston Ridge Observatory this morning. Showery weather with lowering freezing levels is expected today.

Posted by Raoul Ortega at 09:50 | 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 toward the east-northeast.

Recent observations: Heavy rain and winds have made seismic signals noisy, reduced visibility, and limited our ability to detect small seismic events associated with the eruption. Seismic signals recording mudflows out of the crater have continued during the past 24 hours but are diminishing in size and number.

Posted by Raoul Ortega at 11:22 | 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 northeastward.

Recent observations: Storm noise during periods of heavy rain and strong wind dominates seismic signals from the volcano this morning and likely will continue to do so throughout the day. A magnitude 2.6 earthquake in the Portland area at 9:35 p.m. local time Sunday was recorded by stations in the Mount St. Helens seismic network but is unrelated to the ongoing eruption. Acoustic flow monitors are recording signals from rain-induced debris flows in the crater and in the upper reaches of the North and South Fork Toutle River valleys. The storm has caused telemetry outages from a few monitoring stations that will require attention at the next opportunity for field work.

Posted by Raoul Ortega at 18:09 | 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: The volcano is not visible today owing to clouds and heavy rain. Anecdotal reports and signals recorded on acoustic flow monitors on Saturday night suggest that the rains triggered debris flows that descended both the South Fork Toutle River and North Fork Toutle River, but these remain unconfirmed by field checking yet.

Posted by Raoul Ortega at 11:22 | 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 northeastward.

Recent observations: Storm noise during periods of heavy rain and strong wind dominates seismic signals from the volcano this morning and likely will continue to do so throughout the day. A magnitude 2.6 earthquake in the Portland area at 9:35 p.m. local time Sunday was recorded by stations in the Mount St. Helens seismic network but is unrelated to the ongoing eruption. Acoustic flow monitors are recording signals from rain-induced debris flows in the crater and in the upper reaches of the North and South Fork Toutle River valleys. The storm has caused telemetry outages from a few monitoring stations that will require attention at the next opportunity for field work.

Posted by Raoul Ortega at 18:09 | 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 northeastward.

Recent observations: The mountain is not visible today owing to clouds and heavy rain.

Posted by Raoul Ortega at 17:12 | Permalink

Views taken on 2006-Oct-31

Recent observations: A strong Pacific storm is mostly obscuring views of the volcano from Johnston Ridge and elsewhere this morning, and forecasts suggest that a spate of wet weather will likely continue to do so for the next few days. Telemetered data from seismic and ground deformation sensors show no change from established patterns, indicating continued extrusion and dome growth.

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 to the north at low altitudes and from southeast to northeast at higher altitudes.

Recent observations: Clear autumn weather is providing excellent views of the volcano from Johnston Ridge and elsewhere. Field crews took advantage of the good weather yesterday to retrieve images from and re-position a camera in the crater, and to do routine maintenance and winterization of field stations. Continuing rockfalls from the active part of the new dome and repeat images from cameras on the crater rim and floor indicate that the eruption is continuing along previously established trends.

Posted by Raoul Ortega at 10:43 | Permalink