Yellowstone Caldera Activity

[dgavin]

Since Dec 26th, Siesmographs at Yellowstone Park have picked up a Earthquake Swarm event, that is still ongoing.

The event is occuring directly below Yellowstone Lake within the Yellowstone uplift region, about 10km's south of the central most point of the uplift area.

This activity is slowy tapering off, so it appears to be a periodic earthquake swarm event that are associated with regions of volcanic uplift. Similar to the swarm event at The Three Sisters uplift area in 2004.

There has been no increases in Gas emisions or Harmonic Tremors, indicating that this is most likey -NOT- a precursor event to any sort of eruption.

Yellowstone remains at a Normal advisory condition and at an aviation condition of Green.

[dgavin]

Notable earthquake events from the Swarm

MAG DATE LOCAL-TIME LAT LON DEPTH LOCATION
y/m/d h:m:s deg deg km

2.7 2009/01/01 05:51:24 44.548N 110.361W 0.2 60 km (38 mi) ESE of West Yellowstone, MT
2.8 2009/01/01 03:13:51 44.527N 110.353W 2.0 61 km (38 mi) ESE of West Yellowstone, MT
2.6 2009/01/01 03:13:00 44.527N 110.356W 0.0 61 km (38 mi) ESE of West Yellowstone, MT
2.4 2009/01/01 03:12:57 44.325N 110.388W 37.0 68 km (42 mi) ESE of West Yellowstone, MT
1.3 2009/01/01 03:12:32 44.535N 110.365W 0.6 60 km (38 mi) ESE of West Yellowstone, MT
2.3 2009/01/01 03:06:51 44.529N 110.370W 0.5 60 km (37 mi) ESE of West Yellowstone, MT
2.9 2009/01/01 03:02:57 44.530N 110.357W 2.0 61 km (38 mi) ESE of West Yellowstone, MT
1.6 2008/12/31 23:59:39 44.504N 110.340W 0.9 63 km (39 mi) ESE of West Yellowstone, MT
2.2 2008/12/31 22:19:51 44.509N 110.350W 1.7 62 km (39 mi) ESE of West Yellowstone, MT
1.5 2008/12/31 08:05:00 44.514N 110.360W 1.1 61 km (38 mi) ESE of West Yellowstone, MT
3.3 2008/12/31 08:02:11 44.523N 110.361W 4.9 61 km (38 mi) ESE of West Yellowstone, MT
1.3 2008/12/31 04:40:04 44.526N 110.368W 2.2 60 km (38 mi) ESE of West Yellowstone, MT
2.0 2008/12/31 04:06:15 44.533N 110.368W 1.2 60 km (37 mi) ESE of West Yellowstone, MT
1.9 2008/12/31 04:05:12 44.532N 110.380W 0.3 59 km (37 mi) ESE of West Yellowstone, MT
1.1 2008/12/31 03:02:32 44.525N 110.378W 0.7 60 km (37 mi) ESE of West Yellowstone, MT
1.3 2008/12/31 02:56:38 44.525N 110.371W 1.8 60 km (37 mi) ESE of West Yellowstone, MT
1.1 2008/12/31 02:56:09 44.508N 110.362W 2.1 61 km (38 mi) ESE of West Yellowstone, MT
1.1 2008/12/31 02:45:54 44.511N 110.361W 2.5 61 km (38 mi) ESE of West Yellowstone, MT
1.7 2008/12/31 02:45:34 44.507N 110.364W 2.2 61 km (38 mi) ESE of West Yellowstone, MT
1.1 2008/12/31 02:45:02 44.516N 110.370W 2.3 61 km (38 mi) ESE of West Yellowstone, MT
1.2 2008/12/31 02:37:18 44.512N 110.356W 1.5 62 km (38 mi) ESE of West Yellowstone, MT
0.5 2008/12/31 02:35:21 44.724N 111.158W 6.7 8 km ( 5 mi) NNW of West Yellowstone, MT
1.4 2008/12/31 02:34:27 44.522N 110.365W 0.1 61 km (38 mi) ESE of West Yellowstone, MT
1.3 2008/12/31 02:33:05 44.500N 110.369W 3.6 61 km (38 mi) ESE of West Yellowstone, MT
1.3 2008/12/31 02:26:32 44.535N 110.365W 0.9 60 km (38 mi) ESE of West Yellowstone, MT
1.9 2008/12/31 02:21:28 44.533N 110.380W 0.7 59 km (37 mi) ESE of West Yellowstone, MT
0.9 2008/12/31 02:18:31 44.523N 110.367W 1.9 61 km (38 mi) ESE of West Yellowstone, MT
1.4 2008/12/31 02:16:01 44.525N 110.373W 2.2 60 km (37 mi) ESE of West Yellowstone, MT
1.3 2008/12/31 02:13:59 44.514N 110.370W 1.6 61 km (38 mi) ESE of West Yellowstone, MT
2.6 2008/12/31 02:05:59 44.520N 110.368W 0.5 61 km (38 mi) ESE of West Yellowstone, MT
3.6 2008/12/31 02:02:28 44.525N 110.362W 4.3 61 km (38 mi) ESE of West Yellowstone, MT
1.2 2008/12/31 02:00:19 44.518N 110.366W 1.9 61 km (38 mi) ESE of West Yellowstone, MT
2.5 2008/12/31 01:59:21 44.522N 110.362W 0.5 61 km (38 mi) ESE of West Yellowstone, MT
3.0 2008/12/31 01:58:11 44.527N 110.369W 1.3 60 km (37 mi) ESE of West Yellowstone, MT
1.1 2008/12/31 00:27:46 44.535N 110.355W 0.4 61 km (38 mi) ESE of West Yellowstone, MT
0.8 2008/12/31 00:22:00 44.531N 110.376W 1.2 60 km (37 mi) ESE of West Yellowstone, MT
0.1 2008/12/30 23:39:04 44.734N 111.217W 3.4 12 km ( 7 mi) NW of West Yellowstone, MT
1.0 2008/12/30 23:19:28 44.528N 110.378W 1.0 60 km (37 mi) ESE of West Yellowstone, MT
1.5 2008/12/30 23:02:54 44.529N 110.358W 2.0 61 km (38 mi) ESE of West Yellowstone, MT
3.3 2008/12/29 12:14:49 44.521N 110.369W 1.8 60 km (38 mi) ESE of West Yellowstone, MT
3.1 2008/12/28 12:55:17 44.511N 110.353W 0.7 62 km (38 mi) ESE of West Yellowstone, MT
3.0 2008/12/28 12:32:15 44.511N 110.356W 2.7 62 km (38 mi) ESE of West Yellowstone, MT
3.2 2008/12/28 02:23:57 44.511N 110.361W 0.4 61 km (38 mi) ESE of West Yellowstone, MT
3.9 2008/12/27 22:15:56 44.502N 110.366W 0.3 61 km (38 mi) ESE of West Yellowstone, MT
3.3 2008/12/27 15:30:03 44.498N 110.358W 4.3 62 km (39 mi) ESE of West Yellowstone, MT
3.2 2008/12/27 13:26:27 44.505N 110.364W 2.4 61 km (38 mi) ESE of West Yellowstone, MT
3.5 2008/12/27 13:17:33 44.488N 110.357W 4.1 62 km (39 mi) ESE of West Yellowstone, MT
3.0 2008/12/27 11:23:07 44.495N 110.364W 2.8 62 km (38 mi) ESE of West Yellowstone, MT

*edit - added newer events 1-1-09*

[geonuc]

I think we have a thread discussing this already. Two, in fact.

[geonuc]

Never mind. I see you announced you were starting this thread over in one of the other ones.

[dgavin]

New information on this. There may have been a -brief- Harmonic Tremor today at Yellowstone.

I am not a professionaly siesmologist, so I could be misstaking the reading, but the webicorder signature seems match Harmonic Tremor signatures i've looked at before.

The following link that should be good for 10 days. The tremor starts just after 1200 hours and ceases about at 2100 hours. Roughly a 9 hour tremor.

I don't know what this means yet. And I'm not goign to even guess at it as I have misread siesmographs a few times before.

http://www.seis.utah.edu/helicorder/...2008123100.gif

[HenrikOlsen]

Or, as I mentioned in one of the other threads, it might be wind, some of the Yellowstone seismometers are vulnerable to picking up vibrations caused by high winds.
You have to compare to the others in the area to see what's actually going on.

[dgavin]

I took a look at al the other siesmographs, and like with the earth quake swarm reedings, the harmoic like signature is present on two of the other closer siesmographs, but less intence.

Siesmographs further away then these three but still in the region had negligable to no readings at all around the same time.

However, almost 10 Siesmographs lost connectivity around 7 pm during the height of this signature. That usually happens when there is a storm that breaks comm lines or covers the solar panels with snow. All 10 lost connectivity at the same time so i's say either storm damage, or a loss of a comm line.

If it is a Harmonic Tremor, USGS should post an update about to Friday. I'll keep tuned in for that. If not, I'll email a contact at CVO and query him as to the nature of the signature.

It's still looking a bit like a brief Harmonic Tremor signature. I compares it to the Harmonic Signature on Old Faithfuls siesmograph (from is periodic gysering). It's about 5 times the power of the Gysering signature, and less smooth in that there are more variences in it's intensity as you can see in that link.

Over all, unless it was a very very localized storm (which is possible?), i'm leaning more towords a harmonic tremor explaination right now. I don't think a storm would of been quite that localized.

[dgavin]

*eye roll*

The internet rumor mill has started. The latest rumor is that the siemographs that all went offline at 7pm last night, were taken off by USGS on purpose...

*eye roll*
*eye roll*
*head shake, face plant*

I'll at least try to keep the information here accurate and only post outcomes when there is some real data to go off of.

[dgavin]

I did some charting after getting a hold of the the USGS earthquake datasets.

The general trends so far show a few things.

The distribution by location appears fairly concentrated around a specific region. But without any pattern that might indicate longitudinal or latitudinal migration of them.

The distribution of time and depth does indicate a slow trend of decreasing depth of the events over time. However a five day dataset is definitely to small to say if this is any sort of real trend or not.

Please forgive the Spelling error the charts, I didn't notice those until after exporting them to graphics.

[geonuc]

The distribution by location appears fairly concentrated around a specific region. But without any pattern that might indicate longitudinal or latitudinal migration of them.

Longitude/latitude vs time would show any migration.

Nice work, by the way.

[Bozola]

Longitude/latitude vs time would show any migration.

Nice work, by the way.

USGS

[geonuc]

USGS

Thanks, but I was suggesting dgavin could produce another chart, similar to those he's done already.

[dgavin]

Report for this morning.

The Swarm activity is continuing, but at the less frequent rate thats it's shown for the last few days.

*Retraction - This Harmonic appearing series was a Wind Storm*

Orginal Retracted Text : Again -if- (and this is a big if, I am NOT a professional) I'm reading all the siesmographs correctly, there was a series of 3 harmonic tremors starting at 5:30pm MST last night, picked up on the same three stations, the thrid in the series more intense at around 12:20 am this mornign, and being picked up on 6 stations.

I will say this, I have been reading up on harmonic tremors as much as possible, and I think I'me reading the information correctly.
*End Retraction*

What I have found out though in a Gyser active region like this, this sort of activity could be the prelude to the formation of a new gyser, and not eruptive volcanic activity.

I'm still camping on the USGS notices for an update from them.

[dgavin]

Thanks, but I was suggesting dgavin could produce another chart, similar to those he's done already.

I will, when i grab the next dataset!

[dgavin]

USGS has sent out a notice dated on the mornign of the 1st. No mention of the harmonic tremor activity yet.

They did say they were very busy analyzing over 400 EQ events from this swarm. I suspect they are rather busy with that! And they are still saying that they don't have enough information yet to nail down a fault location.

[dgavin]

Retracting part of an earlier post, the Harmonic Tremor appearing reading this morning was from a wind storm. Itilazied the orginal text in post and marked it as a retraction.

I'll be processing a new dataset and charts this evening.

[Gillianren]

Shouldn't they know to, like, cover the seismograph or something?

[cjameshuff]

Shouldn't they know to, like, cover the seismograph or something?

Wind can be pretty rough. Air's about 1.2 kg/m^3. In a 50 kph wind, that's 1.7 metric tons of air bouncing into a 10x10 m square obstacle per second. Depending on the form of the land, the ground itself beneath the seismometers may have been shaking due to gusts of wind...even if that's negligible, a simple cinderblock hut (just as an example, don't know if this is what they actually use) might not be enough to eliminate the effects. Also, I doubt they are all in the most accessible of locations, and it may have been a choice between placing more of them and making them windproof.

[dgavin]

Actually, wind causing the tree's to sway is what adds most of the wind energy to the ground that seismographs then pick up. Brush and small buildings can add a little bit of energy to the ground also. The taller something is, the more sway energy from wind is imparted to the ground.

Trying to cover all the tree's or skyscrapers, would be an interesting technical challenge

[HenrikOlsen]

Retracting part of an earlier post, the Harmonic
Tremor appearing reading this morning was from a wind storm.

So I called it correctly?

Shouldn't they know to, like, cover the seismograph or something?

If the wind shakes nearby trees, the ground the trees grow in shakes and depending on the type of soil that will be picked up by the seismometer. Covering won't help as the ground is actually shaking, just not from seismic activity.

Others are in places where garbage trucks driving by registers as small tremors, but they can recognize those by the time of day they happen.

They do know which of the seismometers are vulnerable to these types of interference and will adjust for them in the published earthquake data since those are the result of combining the measurements from multiple seismometers, even if they can't remove the effect from the raw data.

[dgavin]

So I called it correctly?

For that second set of 3 harmonics, yes, definitely. I should of been clued in by the one that was Saturated earlier.

The first one I'd say it's 50/50 either way. I Haven't been able to find any historic wind data for that period of time at Yellowstone. Probably just not searching with the right parameters. However, none of them was saturated either.

I have some new earthquake charts done.

The general trends that can be deduced from them are:

• A movement northward of the swarm
• A decrease in the average depth of the quakes
• Decrease of frequency from initial stages
• Increase of the ratio of larger magnitude quakes towards lower magnitude ones
• A very periodic occurrence of them, coming in spurts with quiet between.

I think there is enough data so far to say that it appears this swarm is most likely due to a new fault zone forming under Yellowstone lake. The periodic nature of these events, hints, that it might be being assisted by heated water or steam.

There is not enough data yet to tell if any steam or hot water might break surface.

[geonuc]

I think there is enough data so far to say that it appears this swarm is most likely due to a new fault zone forming under Yellowstone lake. The periodic nature of these events, hints, that it might be being assisted by heated water or steam.

How significant, do you suppose? By that, I mean would this formation of new faults be consistent with past observed trends, or would it be unusual or unexpected for one reason or another?

Someday, maybe soon, Old Faithful will no longer blow. There's a lot of tourist infrastructure built up around that geyser.

[dgavin]

USGS has released some official news.

This earthquake sequence is the most intense in this area for some years. No damage has been reported within Yellowstone National Park, nor would any be expected from earthquakes of this size. The swarm is in a region of historical earthquake activity and is close to areas of Yellowstone famous hydrothermal activity. Similar earthquake swarms have occurred in the past in Yellowstone without triggering steam explosions or volcanic activity. Nevertheless, there is some potential for hydrothermal explosions and earthquakes may continue or increase in magnitude. There is a much lower potential for related volcanic activity.

Advisory status is remaining at Normal and Aviation Code of Green.

Geonuc, In this case there are not enough observed past trends to tell if something like this has happened before or not. It's likely there was. Anytime you have an uplift region, new fault zones will form due to the stresses on occasion. So I'd say it was consistent.

I wouldn't worry about any geyser ceasing either, that sort of happening would only be because the heat source was cooling off. Earthquakes might cause a geyser to find a new channel, but think it would be rare for a earthquake to actually stop one cold.

[Swift]

Someday, maybe soon, Old Faithful will no longer blow. There's a lot of tourist infrastructure built up around that geyser.

IIRC the various geysers in the park are constantly changing (becoming more or less active), in the 100 years or so that humans have been recording their activity. It is quite likely that Old Faithful will stop someday.

[jj_0001]

IIRC the various geysers in the park are constantly changing (becoming more or less active), in the 100 years or so that humans have been recording their activity. It is quite likely that Old Faithful will stop someday.

Geysers, geologically, are emipheral phenominon.

So "in our lifetime" woudn't be a bad guess. Of course, unless there is "significant rearrangement" the energy is likely to show up somewhere near the old geyser.

[geonuc]

I don't think it would take much to stop Old Faithful. The geyser blows because its chamber refills after venting and because the geometry and structure of the geyser is just so. If that water is prevented from entering the chamber or if the chamber's geometry is altered, no Old Faithful. Maybe now just an ACME steam vent and maybe shifted a hundred meters. The ground in that area of the park has plenty of other outlets for heat energy to escape.

I'm just musing about the geyser - the current earthquake swarm probably won't affect things except right around where the magma is moving/upwelling.

[dgavin]

Well, it's been almost two days and not a peep out of the seismographs. Too soon to say if it's over though.

A short swarm like this, with a definite pattern of decreasing depth and movement in specific directions over days, instead of weeks or months, is an indication of something more fluid then magma moving. In this case most likely super heated water, or steam.

If the swarm does not start back up within a few weeks, then likely it's depressurized enough that it could be over.

[jj_0001]

The ground in that area of the park has plenty of other outlets for heat energy to escape.

Boy oh boy is that for sure

I'm just musing about the geyser - the current earthquake swarm probably won't affect things except right around where the magma is moving/upwelling.

Magma or hot water. Consider, isn't the west thumb a hydrothermal explosion?

[Jens]

Trying to cover all the tree's or skyscrapers, would be an interesting technical challenge

Just cut down all the trees, and demolish the skyscrapers.

[dgavin]

Two very minor quakes this morning, but nothing to indicate the swarm might be restarting.

Looks like this may be a similar event to the Three Sisters and Mt. Shasta swarms.

It will still need weeks of monitoring to know for sure, but at this point I'll go out on a limb and say it is most likely over with, for the immediate future.