Tuesday, 08 March 2005

I was driving home from work today, crossed over Cornelius Pass Road and onto Highway 30. As I drove down the road I caught a glimpse of Mt. St. Helens, with what looked to be a standard-fare steam plume, typical of what one sees popping over the crater these days, coming out of it. The mountain dropped out of view behind some trees as I drove, and when I rounded a corner and saw it again a few minutes later, I noticed the plume was growing. Within a couple of minutes the plume was thousands of feet in the air. Huge. Pretty amazing really.

Anyhow, for what it's worth, here is my not-so-scientific observation...

First of all, the white cloud looked to be mostly a whole lot of steam. Some darker material appeared to be dropping over to the east of the mountain from the cloud, but honestly it's hard to tell shadows from falling material. The National Weather Service issued an ash-fall warning for that area.

Helens_blows200x160  050308usgs_helens

(Photos from KGW and USGS)

It looked like a bomb hit for a while, a big bulb of a cloud rising straight up from the crater. Then the wind started to push it to the east, and eventually it dropped and started to dissipate.

In my super-geek analysis, I can tell you that this was probably the new dome area involved, rather than the old dome. No surprise there. Why do I say that? Easy. It's a complete guesstimate...

Here is the new dome's seismograph, going offline first (click for large image):


...and here is the old dome's seismograph, knocked offline later than the new dome equipment:


Pretty amazing sight this evening. Unfortunately, I didn't have my good camera with me, but others have done plenty to photograph it.

UPDATE: USGS web site details and images on March 8 eruption.

Wednesday, 09 March 2005 01:05:53 (Pacific Standard Time, UTC-08:00)
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 Tuesday, 25 January 2005

Mt. St. Helens continues to rumble and spew steam and ash, and Portland, Oregon radio station 1190 KEX posted a news story today with audio from the instrumentation used to monitor and listen to the mountain as it continues it's activity.

Wednesday, 26 January 2005 03:58:17 (Pacific Standard Time, UTC-08:00)
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 Saturday, 18 December 2004

Despite the fact that it’s right there in front of my face every time I walk out the door, I’ve started to forget that St Helens is still quite active and spewing steam. A fresh series of four earthquakes (magnitude 2.5 to 3) in the past couple of days and more steam vents prove it. In fact, the mountain is adding new material to the dome growing in the crater at a pretty amazing rate – the equivalent of one dump truck load of new material every second.

This picture was taken this morning from my front porch:


If you’re too young or just plain don’t remember, St. Helens used to be kind of pointy and tall (click the image below for historical photos from before and during the 1980 eruption event:


Scientists say that at this rate, in just 11 years the mountain could be back to the about the same size it was before it completely blew its top back in 1980. There’s no guarantee of that, and lots of variables are involved, of course. However, it’s pretty amazing to note that in just the last couple of months, the new lava dome in the crater has grown one third the size of the dome that took six years to form after the 1980 eruption. Here’s a picture of the growth of the new dome as of November 12, 2004, with a football field graphical overlay for scale purposes:

The mountain remains under what they call a Level Two volcano advisory, meaning the Johnston Ridge visitor center – the one closest to the crater - is still closed, but the Coldwater Creek visitor center is open. For those who cannot visit, the Volcano Cam offers a great view into the crater 24/7.

I have had a lot of inquiries from people who know me (and some who don’t) about how close I live to the mountain. I guess people think we’re all gonna die. We’re not. My house is something like 50 or so miles away as the crow flies, so no worries there.

The latest info can always be found at the Pacific Northwest Seismograph Network web site and the USGS Cascade Range web site. KATU News in Portland did a good update, and you can read it on their web site and watch the streaming video of their news report.

By the way – St. Helens is not the only volcano in the area, it’s just the one that’s acting up right now. All the other volcanoes in the Cascade Range are all at normal levels of background seismicity. They include:

  • Mount Baker, in Washington
  • Glacier Peak, in Washington
  • Mount Rainier, in Washington
  • Mount Adams, in Washington
  • Mount Hood, in Oregon
  • Mount Jefferson, in Oregon
  • Three Sisters, in Oregon
  • Newberry, in Oregon
  • Crater Lake, in Oregon
  • Medicine Lake, in northern California
  • Mount Shasta, in northern California
  • Lassen Peak in northern California
Saturday, 18 December 2004 18:31:26 (Pacific Standard Time, UTC-08:00)
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 Thursday, 04 November 2004

Not much has been said recently in the news about Mt. St. Helens and the fact that it's still active and spewing some steam and ash. The alert level for volcanic unrest, as they call it, remains at Orange. Earlier today USGS photographers took some pictures from the air of a steam and ash eruption (it's actually been ongoing for almost a month now). A new lava dome has formed, and continues to be active and grow.

From the USGS: “Seismicity remains at a low level compared to that observed early in this unrest. The current seismicity is consistent with a continuing, slow rise of magma driving uplift of the crater floor and feeding a surface extrusion of lava. The overall low rates of seismicity and gas emission suggest that the lava reaching the surface is gas poor, thereby reducing the probability of highly explosive eruptions in the near term.”

These images are from November 4th. Click the images to go to the official web site, where more pictures and info can be found. Note the ash stains on the snow in both images. You might also be interested in the "repeat views" image gallery, which contains same-angle images over time, so you can see the progression of change.

Friday, 05 November 2004 04:59:24 (Pacific Standard Time, UTC-08:00)
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 Monday, 11 October 2004

Heat scans are now showing greatly increased temperatures at the surface in the volcano crater and earthquakes are occurring at about one every five minutes. Scientists are saying this shows magma is much closer to the surface, and gas measurements also support this.

When I woke up this morning and was getting ready for work, I looked out the front window, from which I can see the mountain, and saw a column of steam lifting out of the crater. This was the first time I have been home at a time when clouds were cleared and something was happening.

I shot a couple of pictures, and will try to get around to transferring them from the camera to the computer and uploading soon.

Tuesday, 12 October 2004 04:09:53 (Pacific Daylight Time, UTC-07:00)
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 Sunday, 10 October 2004

The volcano's seismic activity built back up again after dropping off a few days ago, and finally released more steam at about 7am today.

The advisory is still at Level 2 and earthquakes are not as frequent as they were before. A second dome, or “blister” has been pushing up next to the one formed in the crater in the 1980's. The old dome was formed between 1980 and 1986. The new dome has been formed over the past couple of weeks, and is already bigger than the one formed in the 80's.

Sunday, 10 October 2004 15:12:30 (Pacific Daylight Time, UTC-07:00)
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 Tuesday, 05 October 2004

Yes, people, we are still alive here - the media in some places is getting overly excited. Really, nothing has happened as far as any major events. There is no ash in Portland or pretty much anywhere else as of today. Please stay calm, move along, nothing to see here (well nothing catostrophic anyhow, but plenty of interesting stuff). If you want to keep in touch with updates on the volcano as I post them, I have created a new category for posts and a matching feed.

Mt. St. Helens this morning let off the largest of its steam and ash emissions so far since the new volcanic activity started. Portland's KATU News got some great spot video becasue they just happened to be in the air when it started. Interestingly, the seismic activity dropped off when this emission took place, and has remained mostly low-level since.

In the image below, taken from the University of Washington's webicorders of the St. Helens South Ridge seismographic station, the seismic activity drops off right after 9am, which is when the new cloud of ash and steam was emitted:

Activity has - as you can see - stayed at a lower level since, with a few larger quakes occurring among a lot of smaller ones.

Clicking on either image will open a new window with the full size image from the U of W webicorder site.

An interesting anomaly on the webicorder readout during the 11am Pacific Time hour shows what is either a strange (harmonic?) event or a simple error in the seismic recording. Anyone know or have any idea what the wandering lines represent?

At any rate, ash and steam from the mountain went thousands of feet in the air and for the first time ash amounts were detectable on weather radar. Small amounts of ash fell around small towns northeast of the mountain and on US Hwy 12, which resulted in reduced visibility, according to media reports.

The lava dome, which was formed between the big explosive event in 1980 and 1986, has raised more than 150 feet since the events started. Last week they were excited over a 2 centimeter lift - In the past 36 hours the dome has lifted more than 50 feet.

The forecast is for more events like the ones we have been seeing, with a likelihood of an eventual (sooner or later) explosive event. If magma (hot molten rock) reaching the surface (at which point it's called lava) is new magma from deep inside the earth, it will contain lots of compressed gasses, which will create an explosive type of event that throws rock and ash in the air. If it is old magma, perhaps left over in a relatively shallow cavern from the 1980 eruption, it might not contain as much gas, and as a result it may just flow out and help build a newer, bigger dome in the volcano's crater, a process that could - eventually - build the mountain back up again.

But the amount of ash being thrown about has grown with each steam eruption so far, and the levels of magmatic gasses have also grown, so I am betting on bigger event, rather than smaller. Nothing like 1980, mind you - but spectacular, I will bet.

Those Earth Science classes in high school and junior high did some good after all. See? Good teachers make all the difference in the world.

Wednesday, 06 October 2004 01:14:59 (Pacific Daylight Time, UTC-07:00)
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 Monday, 04 October 2004

When it's light out, it's great... When it's dark out, it's... well... dark. If it gets cloudy... you get the point. Click the picture below for the full-size image.

Tuesday, 05 October 2004 04:18:36 (Pacific Daylight Time, UTC-07:00)
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I arrived back in Portland yesterday afternoon, and was met by my mom at the airport because she happened to be in town. Great timing, since Mt. St. Helens is coughing up steam and stuff these days. We made some stops along the drive home to look at the mountain (there are lots of great viewpoints near where I live). This morning we watched the big steam venting out of the crater, and then we drove back to the airport for her flight home.

Image, click to enlargeIt looks like the volcano is getting ready for something bigger. I have tried to estimate my house's distance from the volcano, because people keep asking (I assume out of concern). It looks like I live somewhere between 40 and 45 miles from the volcano (I will map it out sometime soon). So, no fears - the worst thing that would happen here is ash fallout (which can be problematic if you breathe it or get it in your eyes, and it's nasty on car paint and windows). But the winds at the mountain are blowing directly away from here right now. If it's going to blow, I just hope it happens when I am home, so I can snap some pictures and watch. And, in true form, Dan Appleman (whom I met at the conference last week) has some funny observations on volcanoes and politics that will generate a laugh or two. (Image by USGS, click for more pictures, or for seismographic info from the Cascade Mountains)

USGS Update: Mount St. Helens Update 4 October 2004 7:00 P.M.

Current status is Volcano Alert (Alert Level 3); aviation color code RED

This morning visitors to Mount St. Helens witnessed a 40-minute-long steam-and-ash emission starting at 9:43 PDT. Steam clouds carrying minor ash billowed out of the crater to an altitude of 10,000 to perhaps 12,000 feet. The event did not generate earthquakes or an explosion signal. We infer that hot rock was pushed up into the glacier, melted ice, and generated the steam. Part of the vent for today’s and other steam and ash emissions of the past few days is now covered by a boiling lake. The emission occurred during a time of gradually increasing seismicity, which dropped slightly after the emission, but continued to increase gradually through the afternoon. Another period of smaller steam and ash bursts occurred between 2:10 and 2:40 P.M. Visual observations show that the area of uplift, which includes part of the glacier and a nearby segment of the south flank of the lava dome, continues to rise. We infer that magma is at a very shallow level and could soon be extruded into the vent or elsewhere in the deforming area. Additional steam and ash emissions are likely and could occur at any time without warning. Conditions suggest that there is also an increased probability of larger-magnitude and more ash-rich eruptions in coming days.

Yesterday’s gas-sensing flight detected slightly lower concentrations of carbon dioxide in the crater, but for the first time the airborne instruments detected the presence of hydrogen sulfide. Wind conditions during today’s flight should permit the first estimation of the rate of gas flux.

Tuesday, 05 October 2004 00:31:06 (Pacific Daylight Time, UTC-07:00)
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 Saturday, 02 October 2004

I'm sitting in California at a geek conference (til tomorrow), and so I am missing the up-close excitement of what's happening at St. Helen's. The USGS raised the volcano cautionary level to III (press conference video link - WMV) today and evacuated the immediate area. Geologist say all indications are that magma is moving underground in the crater.

There's a good slideshow on KATU TV's web site from Friday's eruption. The KATU web site has a lot of great information and video, and you don't have to sign up and start getting spammed to access it, unlike on some other PDX news station sites. Score one for KATU - that's customer oriented content publishing. Thanks to KATU's decision-makers for that.

Saturday, 02 October 2004 22:11:32 (Pacific Daylight Time, UTC-07:00)
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 Friday, 01 October 2004


Mount St. Helens Notice of Volcano Alert, October 2, 2004

A notice of Volcano Alert (Alert Level 3) was issued today at 2:00 p.m. PDT

Immediately after the small steam emission at 12:15, seismic activity changed from principally rock breakage events to continuous low-frequency tremor, which is indicative of magma movement. We are increasing the alert level to Volcano Alert the highest alert level indicating that an eruption could be imminent.

The cause and outcome of the accelerating unrest is uncertain. Explosions from the vent could occur suddenly and without further warning. During such explosions the dome and crater floor are at greatest risk from ballistic projectiles, but the rim of the crater and flanks of the volcano could also be at risk. Explosions would also be expected to produce ash clouds that rise several to tens of thousands of feet above the crater rim and drift downwind. Currently wind forecasts from the National Weather Service, combined with eruption models, show that ash clouds will move to the northwest. If ash emissions are large, drifting ash could affect downwind communities. Minor melting of the glacier could trigger debris flows from the crater that are large enough to reach the Pumice Plain. There is very low probability that downstream communities would be impacted by these hydrologic events.

We continue to monitor the situation very closely and will issue additional updates as warranted, whether activity escalates or returns to background levels.


Mount St. Helens Update, October 1, 2004, 7:00 P.M.

Current status is Alert-Level 2-Volcano Advisory

The increasingly energetic seismic swarm of the past week culminated in a small 25-miunute-long eruption around noon today from a vent just south of the lava dome. The vent opened in a portion of the glacier that had become increasingly crevassed and uplifted over the past few days. This deformation was probably driven by piston-like uplift of a portion of the lava dome and crater floor. The eruption sent a steam and minor ash plume to an altitude of about 10,000 ft. It drifted southwestward accompanied by minor ashfall in areas close to the volcano. Seismicity dropped to a low level for several hours after the eruption, but is gradually increasing with earthquakes (maximum Magnitude about 3) occurring a rate of 1-2 per minute. We infer that the system is repressurizing. As a result, additional steam-and-ash eruptions similar to today’s could occur at any time.

Saturday, 02 October 2004 02:22:19 (Pacific Daylight Time, UTC-07:00)
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 Wednesday, 29 September 2004

USGS officials are holding a news conference right now, and have just announced an explosive event on Mt St Helens is possible, and the alert level has just been raised by the USGS for the mountain. The lava dome in the crater has apparently moved a measurable amount, and seismic activity has taken a noticible upturn.

They are now seeing quakes at the rate of 4 a minute. They are larger quakes, 2 to 2.5 in magnitude. Describing the seismic activity, they say it is definitely ramping up and plateauing in phases, not falling back down. Explosion and ash are the risks. This behavior is similar to what was observed on the mountain in 1986: Big increases in seismic energy over past 8 hours.

I'm at the airport flying out to Reno at 12:45, mobile posting from my handheld device. I hope it keeps its top on.

Update: USGS Advisories and information about the mountain activity available here.

Wednesday, 29 September 2004 16:23:42 (Pacific Daylight Time, UTC-07:00)
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 Monday, 27 September 2004
Sunrise over St Helens from HomeClearly visible from the front porch of my house, across the river over there in Washington, Mt. St. Helens is getting restless. Standing in the yard looking at the mountain in the hazy sky, it looked just like it does any other day, but apparently it's been grumbling more than it usually does under the surface - enough for the USGS to take official notice, anyhow.
Here is the seismic-activity recording from Wednesday evening last week (the seismograph readout shows a 12-hour block from noon to midnight UTC, which is 9pm to 5am PDT), which looks pretty normal:

And the following are the subsequent 12-hour periods, from September 23rd on through to this evening...

September 23 0000-1159

September 23 1200-2359

September 24 0000-1159

September 24 1200-2359

September 25 0000-1159

September 25 1200-2359

September 26 0000-1159

September 26 1200-2359

September 27 0000-1159 (partial)

All images come from the webicorders system at the Pacific Northwest Seismograph Network. On the webicorders page, scroll down and see the links under "SEP EHZ UW : St. Helens - Dome Station" for the latest data.

In addition, news reports are now saying that the USGS has issued a "notice of volcanic unrest" for the mountain: "Initially, hundreds of tiny earthquakes that began Thursday morning had slowly declined through Saturday. By Sunday, however, the swarm had changed to include more than 10 larger earthquakes of magnitude 2.0 to 2.8, the most in a 24-hour period since the last dome-building eruption in October 1986, Scott said."

The full Seattle P-I news story can be read here.
Monday, 27 September 2004 05:57:33 (Pacific Daylight Time, UTC-07:00)
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