Rainier Earthquakes

I posted about this on the quake watch thread, but I thought I should mention it here.

earthquake.usgs.gov...

This earthquake occurred last Saturday, local time.

Since then there have been a series of other earthquakes. Should this be a cause for concern?

All the quakes are on the east side of the Volcano. I cannot find anything about the quakes on the USGS volcano sites.

Does anyone else know about this?

From the date i have seen the volcano is ok at the sec,

ill try and find some info and get back on here with it,



(edited to add)

Rainier quake not volcanic
VANCOUVER, Wash. Scientists at the Cascades Volcano Observatory in Vancouver say a shallow earthquake east of Mount Rainier was not a sign of a coming eruption.

Geologist Julie Griswold says the four-point-five quake Saturday night was not related to volcanic activity.

More than 12-hundred people reported feeling the quake, which was followed by dozens of small aftershocks.

www.kndo.com...


One to watch though i would say, i wonder could these quakes set off movement in the volcano,

[edit on 10-10-2006 by asala]

There are still aftershocks going on in the area. The main pages from usgs links are still not updated, even though they say they are daily

www.pnsn.org...

The way the aftershocks are going I would have thought maybe a new vent was coming up, but I think i should trust the report it is not volcanic. But if it isn't volcanic, I can't see where the fault is that it is happening on.

When Mt. St. Helens woke back up in '04, I learned that if you're wanting up-to-the-second info on the seismic activity in the cascades, don't trust most of the reports you find. I'm sure the geologists have much better things to do than play with websites

www.pnsn.org...
This link will take you to where you can view the seismograph readings. It's updated pretty much every five minutes, give or take; I believe it's automatically fed from the machines, but I don't know for sure one way or the other. Good luck trying to measure out a Richter number for anything you find though

ok so this is a small one, but it is slightly worrying that there are still small earthquakes going on to one side of Rainier:

earthquake.usgs.gov...

This activity seems similar to that which can be seen on the maps of Kilauea and St helens to me.

Another small earthquake in the same place. I wonder what is going on there.

Another one that is small, but usually the normal really small ones aren't shown so I thought I would mention it.

earthquake.usgs.gov...

This one works out as 1.1km southwest of the crater.

Edit, looking at this in Google earth 3D, this is perhaps near the actual lava pipe in the volcano? It is at 1 km down from surface, on a 4.2 km high volcano that must be near the pipe?

[edit on 24-10-2006 by apex]

Another on the eastern flank:

Magnitude 1.1 - WASHINGTON

6.8km depth

earthquake.usgs.gov...

I don't have a problem with only me posting here, I just wonder about what is happening here.

Magnitude 2.1 - WASHINGTON
Depth 4.9km
earthquake.usgs.gov...

I'm just observing Apex, so am keeping up to date

It sure is rumbling, I just wonder what it has been other years so we could match it up,

Well up until recently, every time I looked on the USGS page there hasn't been an earthquake on Rainier that was listed.

Just found this, going back to mid june, quakes on the summit,

DATE-(UTC)-TIME LAT(N) LON(W) DEP MAG QUAL COMMENTS
yy/mm/dd hh:mm:ss deg. deg. km Ml
06/06/16 17:36:16 46.85N 121.76W 1.2 1.4 BA
06/06/18 06:11:09 46.87N 121.75W 0.4 0.9 BB
06/06/23 12:11:31 46.84N 121.77W 2.2 0.6 AB
06/07/25 08:40:13 46.85N 121.76W 3.7 0.3 AB
06/07/29 05:52:24 46.84N 121.76W 1.6 0.0 AA
06/08/12 00:50:13 46.85N 121.76W 1.1 1.4 AA
06/08/15 07:12:26 46.84N 121.75W 3.4 0.4 AB
06/08/31 03:23:25 46.84N 121.76W 2.1 0.2 AB
06/08/31 06:17:16 46.85N 121.76W 0.0 1.7 AB
06/08/31 22:50:33 46.85N 121.76W 0.0 1.1 AB
06/09/10 21:13:24 46.85N 121.76W 1.0 1.2 AB
06/09/18 06:07:32 46.84N 121.77W 0.5-0.3 AC
06/09/22 18:43:44 46.85N 121.75W 0.5 0.4 AB
06/10/01 03:45:37 46.84N 121.76W 1.7 0.4 AA
06/10/05 09:01:43 46.85N 121.77W 2.2 0.3 AC
06/10/16 14:11:45 46.86N 121.78W 0.2-0.1 AC
06/10/22 23:19:05 46.84N 121.76W 0.1-0.6 AC
06/10/23 11:37:37 46.84N 121.77W 0.9-0.8 AC
06/10/24 08:39:08 46.84N 121.76W 1.0 1.1 AA
06/10/24 09:04:07 46.84N 121.76W 0.0 0.5 CC

Source

Of course, the current activity doesn't seem to be at the summit, but the flank.

Edit, just found this;

www.geophys.washington.edu...

It seems to show more earthquakes at the present and recently than this time a year ago.

[edit on 27-10-2006 by apex]

And i'd thought, and hoped that there wouldn't be any more:

Magnitude 1.4 - WASHINGTON

Depth 6.4km

earthquake.usgs.gov...

Still Rumbling a bit

Magnitude 1.6 - WASHINGTON
Depth 5.2km

earthquake.usgs.gov...

I'm wondering at what point do they close down the mountain to hiking? Only when they feel an imminent threat of eruption? I'm not sure if they'll know when or if that is to occur. I know I wouldn't be hiking across the glaciers on top of Mt. Rainier if earthquakes were routinely going on.

So is the evidence suggesting that magma is rising towards the surface?

I don't know what they are going to do with this issue. All I'm thinking is that these quakes look quite similar to the earthquake swarms that happen at yellowstone, so it could be magma rising, the first was at a depth of 3.8km, but these later ones seem to be lower. Of course a new lava tunnel could be widening to make a new chamber I suppose.

Theres two that I can see at the moment, one at the crater area:

earthquake.usgs.gov...
at 1km depth

And A 2.2 at the side:

earthquake.usgs.gov...

Both of these are given as being at the surface.

Heres some more at the summit:

06/11/04 02:15:24 46.85N 121.73W 0.2 1.8 AB
06/11/04 03:07:29 46.85N 121.74W 0.1 1.0 AC
06/11/04 06:56:44 46.87N 121.84W 7.4 0.5 BB

This is interesting, looking at these displays:

www.pnsn.org...

Does anyone know what exactly this is here, because its quite constant, so is this harmonic tremor perhaps?

One of the other ones show this sort of thing, and the other two show a lot of tremor sort of thing happening constantly.

www.pnsn.org...

[edit on 6-11-2006 by apex]

That first graph looks suspiciously like HT's to me, but I'm no vulcanologist. I'm going to go ahead and say this cliche now, it's a matter of 'when' not 'if' with Rainier. I was about 7 when St. Helens blew and remember the darkness in the afternoon vividly, unfortunately when Rainier decides to go it's going to be MUCH worse in terms of loss of life and property.

Looking at this picture, I'm thinking it may be harmonic tremor, remembering that it is at a different timescale. The shallow volcanic earthquakes one looks similar too.