Mount St. Helens Event Occurring Now - March 08, 2005

[Duckster]

There is an ongoing significant steam and ash event taking place right now. It started within the past hour.

I will have more information shortly.

[Neurotik]

Is that a cloud of ash and steam on the webcam or is that just a normal cloud? It’s difficult to tell in the twilight.

[Duckster]

At around 5:25 pm PST there was a significant steam and ash eruption of Mount St. Helens. Sunset today was at 6:09 pm PST so views of the event were pretty incredible. Watch for the CBS network to probably broadcast taped highlights from the local Portland affiliate. They had a helicopter very close to the volcano at the time and views of the new dome within the crater were showing extensive cracking of the new dome and hot magma visible in the cracks.

Three of the four USGS crater seismographs were damaged or destroyed. After about ten minutes earthquake activity subsided back to “normal” levels. The USGS is reporting now that they believe this is a one-off event, probably caused by a collapse of part of the new dome. However, they will not be able to verify the preliminary reports for a day or two. Weather is about to turn tonight and views of the volcano are expected to be obscured.

The steam and ash plume was calculated to 36,000 feet at its height.

The Mount St. Helens VolcanoCam captured the event. However, the time of day and wind direction (actually blowing away from the camera) didn’t give a significant view of the event. The Pacific Northwest Seismograph Network seismographs clearly show the event. Click on the St. Helens Dome and Dome 2 links, and compare them to the Yellow Rock seismograph.

Sidebar - The news media is reporting considerable failures of the cell phone networks in the Portland-Vancouver area as literally everyone was calling everyone when the event began.

[Duckster]

Official USGS first report of the event …

A small explosive event at Mount St. Helens volcano began at approximately 5:25 p.m. PST. Pilot reports indicate that the resulting steam-and-ash plume reached an altitude of about 36,000 feet above sea level within a few minutes and drifted downwind to the east-northeast. The principal event lasted about 30 minutes with intensity gradually declining throughout. The USGS Cascades Volcano Observatory lost radio signals from three monitoring stations in the crater soon after the event started. The cause of the outage won’t be known until scientists can visit the crater tomorrow to assess the situation, weather permitting. The event followed a few hours of slightly increased earthquake activity that was noted but not interpreted as precursory activity. There were no other indications of an imminent change in activity.

The current hazard assessment for the ongoing eruption mentions the possibility of such events occurring without warning, and the assessment remains unchanged. 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.

http://vulcan.wr.usgs.gov/Volcanoes/Cascades/CurrentActivity/current_updates.html

[akwally1]

I’m on post in the Portland area can report that I contributed to the cell collapse when I called my wife at 5:45. Since then, we have been watching the horrid news folks here in PDX and praying the the thing blows and takes out our local new folks.

Wally

[akwally1]

Please, oh please, God of Fire and Thunder…take Tracy Barry away…

[Seven]

@akwally1

I’m on post in the Portland area can report that I contributed to the cell collapse when I called my wife at 5:45.

Same here. My wife was down on the river and saw the plume. She called me at work to have me look it up on-line and tell her what was going on.

Sadly, I missed the whole thing.

[Duckster]

@Seven

Same here. My wife was down on the river and saw the plume. She called me at work to have me look it up on-line and tell her what was going on.

Sadly, I missed the whole thing.

Don’t worry. For once the news media got some quality coverage.

[Gulo_gulo]

This may be a weird question but is there any way to discover what path the ash takes? My husband swears we drove through some ash fall last night and it sure smelled and tasted like it.

(This was driving east from Yakima at about 9PM)

[BurnMeUp]

Reports I caught here on Q13 news said the ash was headed towards Yakima.

[Duckster]

The latest news concerning yesterday’s small eruption from Mount St. Helens is the USGS scientists just do not know what caused it. They still do not know exactly what happened, either.

None of their monitoring equipment indicated beforehand there would be an eruption. While there was a minor ramp-up in earthquake activity prior to the eruption, this was not seen as a precursor. I’m sure they are now revisiting that observation for future possibilities.

As of 2 am PST this morning, or more than eight hours after the eruption, ash was detected in western Montana. The National Weather Service satellite was able to initially track the ash cloud. If you want to know what direction an ash cloud may take on any given day, there is a link from the VolcanoCam home page taking you to the daily NWS ash prediction web site.