Crater Lake Activity

[dgavin]

Crater Lake (Mt. Mazama) had a small micro swarm of earthquakes this week lasting about 8 hours. These were very weak quakes, < 0.1 in magnitude, and nothing to be concerned about. It's considered normal background activity for volcanic regions.

However in 7 years of watching the webicorders for volcanoes, this is the first event like this I have noted at Crater Lake, so posting about it.

Also attaching the webicorder images for a permanent record here.

[hhEb09'1]

Those little blue (and red) squiggles?

[Squink]

Those little blue (and red) squiggles?

Yup. Looks like Llao may finally be emerging from his time in the Below-World.

[dgavin]

Yup. Looks like Llao may finally be emerging from his time in the Below-World.

I wouldn't go that far yet.

This is such weak activity that it is likely only a deep achient and empty lava tube collapsing. Still fairly cool to see when usualy you only see avelanches and rock falls on the siesmographs for Crater Lake.

[EricFD]

It's fun to catch the first activity like this after seven years. Thanks for the webicorder thumbnails.

Eric

[dgavin]

The webicorders been down for a few days, got a change too look back at them and it appears...

That there might have been a harmonic tremor around the Crater Lake region on the 8th, about 9am, and lasting for around 20 minutes. This was also picked up at Roseburg siesmographs as well as a few others.

I still think this isn't anything to be concerned about. But with Yellowstone quieting down, it's definantly got my intrest piqued.

[dgavin]

Wow, and another harmonic tremor at around 3pm yesterday lasting a bit over an hour. I am not certain these at located at crater lake exactly. As they are also picked up at Shata's stations, Roseberg Stations, and the stongest signal at Grantspass station.

All on slow period siesmographs. Definately not a man made signal as it's too wide spread, and I don;t think it's wind. It's too consitant on the stations it shows up on, to be wind.

[dgavin]

I Just got word that there /was/ a EQ swarm at the MT. Lassen area on the 10th, however that only might cover the siesmograph readings I saw on the same day, but not yesterdays longer event.

May or may not be related events.

[dgavin]

Nothing new here since.

I'm still fairly certain that the swarm was more likely from a lava tube collapse. It has some distinct oodities to it that are vaugly similar to those of a sink-hole collapse on seismographs.

The other events looking like tremors, actualy were, but i've nailed down the location best as I could of those (minus the Mt Lassen events), as to being somewhere around Mt. McGloughlin (about half way between crater lake and grants pass). It's about as accurate as I can get without direct access to the seismograph datasets.

So they are unrelated events to the swarm at Crater Lake.

[BigDon]

Yup. Looks like Llao may finally be emerging from his time in the Below-World.

Still, it's better than the Great Horror trapped under there in the Shadow Run millieu. Which was the first thing I thought.

Great Horrors are uniquely bad news as no two are the same. And they didn't get that name by cheating at tiddlywinks.

And collapsing lava tubes are a very bad sign in this instance. It means what occupied them does so no longer.

I shall pay close attention to further developments.

[dgavin]

USGS has produced a new way to list volcanos (instead of acvtive/inactive/dormant) based on threat assement. Very High Risk, High Risk, Moderate Risk, Low Risk, Negligable Risk.

Taking the number 1 Very High Risk postion in Oregon, is Crater Lake.

-What?- Was my main reaction to this, but I've read up on papers behind this new rating scheme and can summerize why, in order of thier value to risk from highest to lowest.

1. Lack of Adaquate Monitoring
2. Indications of Thermal Heating at bottom of Crater Lake (crater lakes bottom is 3-6C warmer then water 100 feet above bottom)
3. Potential of Lake's release of Supersaturated CO2, with potential of additonal Methanehydrates, and other gasses inundated into the water at depth.
4. Potential of Lake Wall Weakening (collapsing) and Massive Flood
5. Potential for Eruptions
6. Potential for super explosive Hydromagmatic Eruptions (Megaton range if magma intrusion into lake occures at same time as lake wall collapse)

[korjik]

Sounds more like USGS has produced a new way to get a bigger budget.

If the monitoring stations are detecting earthquakes at a small fraction of a point in magnitude, then is seems to me that the rest is mostly covered.

[jlhredshift]

I am curious to know if anyone knows of a confirmed exposure of a collapsed magma tube that was at one time at a great depth?

[Swift]

Sounds more like USGS has produced a new way to get a bigger budget.

BAUT has no geology exception to the no-politics rule. Let's not take the conversation in that direction. Thanks,

[dgavin]

Sounds more like USGS has produced a new way to get a bigger budget.

If the monitoring stations are detecting earthquakes at a small fraction of a point in magnitude, then is seems to me that the rest is mostly covered.

Actualy from what I gathered out of the papers, the most prevelent danger (and most likely) at Crater Lake is a disruption of the lake water by an avalanche, landslide or quake, that causes a explosive release of all the supersaturaed CO2 at depth. The papers did not give an amount of estimated CO2, but it did mention that a complete release of all CO2 would cause massive fatalities in the Klamath Basin, with elevated CO2 consentrations reaching as far as Bend and parts of northern california.

That inidcates to me that the CO2 buildup in Crater Lake, is complete Orders of Magnitude greater than the one in africa that released a lethal dosage some years ago.

*edit, spelling and to add*

This sort of event would likely have no seismic forwarning to it, or very minimal seismic warnings.

[korjik]

Actualy from what I gathered out of the papers, the most prevelent danger (and most likely) at Crater Lake is a disruption of the lake water by an avalanche, landslide or quake, that causes a explosive release of all the supersaturaed CO2 at depth. The papers did not give an amount of estimated CO2, but it did mention that a complete release of all CO2 would cause massive fatalities in the Klamath Basin, with elevated CO2 consentrations reaching as far as Bend and parts of northern california.

That inidcates to me that the CO2 buildup in Crater Lake, is complete Orders of Magnitude greater than the one in africa that released a lethal dosage some years ago.

*edit, spelling and to add*

This sort of event would likely have no seismic forwarning to it, or very minimal seismic warnings.

If that was a likely threat, showing it would not be all that hard. Fixing it would not be all that hard either.

[dgavin]

If that was a likely threat, showing it would not be all that hard. Fixing it would not be all that hard either.

Showing it in real time is not hard, no, giving adaquate warning that such an event might happen, is near impossible, again as there is no precursor activity.

Fixing it is a lot harder then you think, take a good look at picture of crater lake from the rim looking down, then ask yourself, "How the heck do I get all the heavy equipment down the crater rim without Polluting the lake or Casusing man made landslides durign road construction that triggers the CO2 release anyway."

Even then, if release wells are someone constructed, releasing the C02 in the amounts that would change danger levels, would take many well's a few centuries of operation to have any effect on reducing the danger. It would be a most excelent source of power generation however, if you could get around the national park status (which would be very unlikely to happen) to build release well's and power plants.

[dgavin]

I am curious to know if anyone knows of a confirmed exposure of a collapsed magma tube that was at one time at a great depth?

While these were never at 'Great Depth' and they are not that old, Sawyer Caves in Oregon is about as close as you'll get I think. The caves are still largely unexplored, though I've been inside the bigest one, you can't go back to far as it

http://oregoncaves4u.com/sawyers_cave.html

http://paultower.wordpress.com/2010/...%80%99s-caves/

[jlhredshift]

While these were never at 'Great Depth' and they are not that old, Sawyer Caves in Oregon is about as close as you'll get I think. The caves are still largely unexplored, though I've been inside the bigest one, you can't go back to far as it

http://oregoncaves4u.com/sawyers_cave.html

http://paultower.wordpress.com/2010/...%80%99s-caves/

Thanks

[dgavin]

A New crater lake siemograph is online. And it's picking up a lot more then the old one's did, as this baby is on the peak of Scott's Moutain, (which is a small mountain thats on Mt. Mazama itself half way up the east slope).

The link i'm posting show winds storms, ice fracturing, and glacier movement tremors on the one day. Not sure how long these url's will be good for, as they are from the new PNSN website as well.

http://www.pnsn.org/seismogram/2012/12/4/clms/ehz/cc/