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dgavin
2016-Jul-30, 02:23 AM
A small swarm of 27 Earth Quakes started just west of the base of Mt. Rainier on the 16th, and has been continuing through today centering under the mountain itself.

While it is nothing to panic about. Yet. The Plot of the quakes hints that they are occurring along the probable upper edges of a magma chamber, and in the volcanic chimney itself.

John Mendenhall
2016-Jul-30, 03:09 AM
A small swarm of 27 Earth Quakes started just west of the base of Mt. Rainier on the 16th, and has been continuing through today centering under the mountain itself.

While it is nothing to panic about. Yet. The Plot of the quakes hints that they are occurring along the probable upper edges of a magma chamber, and in the volcanic chimney itself.

Thanks, Gavin , enjoy your posts. Good work !

Gillianren
2016-Jul-30, 03:48 PM
It's going to happen sooner or later, and we as a state are simply not prepared. (For the concerned, no, I am nowhere near the danger zone. Though I have friends who are.) I hope the state agencies are better prepared then they were for Mount St. Helens, because this is going to be a whole lot worse.

grapes
2016-Jul-30, 03:55 PM
Love this recent "jump"

https://www.pnsn.org/volcanoes/mount-rainier?limit=20#seismicity

publiusr
2016-Jul-30, 04:36 PM
More here
https://www.volcanodiscovery.com/mount_rainier-earthquakes.html
https://www.pnsn.org/volcanoes/mount-rainier

dgavin
2016-Jul-30, 07:20 PM
I did some analyzing of earthquake data from 2009 to current and it does seems to be hinting the the middle magma chamber is not under the mountain directly, but off to the west side. Lateral vents and chimney's are not that uncommon. Mt. Tabor, most cinder cones, are examples of that.

The mechanisms for magma moving laterally more distance, when there is less surface above it, would be a pre-existing fault, weakness, cave system, or underground river system.

My guess with Mt. Rainier is it was a fault.

Attached some plots of events since2009.

I marked up the overhead map with extrapolated features. The Red Zone being the upper portion of the Middle magma chamber, which feeds through a weakened fault area marked blue, to the Volcanoes upper chamber/chimney in green. The black area is an extrapolation of the lower end of the Middle magma chamber. The Smaller black inner circle is the probable injection site from below.

The purple marked area, are sub-vents, which lead to cider cone fields. The middle one feeding Cowlitz Chimneys/Tamanos Mt. area. The Upper one feeding the Skyscraper Mt./McNeely Peak/Mt. Freemont area. And the south one feeding to the Tatoosh Wilderness, directly under it's highest peak..

I drew those features before looking at the Tomography of the area, which seems to support, a little bit, what I had come up with.

Source The College of New Jersey: http://physics.pages.tcnj.edu/files/2014/07/mt-rainer.jpg

KaiYeves
2016-Jul-30, 07:41 PM
It's going to happen sooner or later, and we as a state are simply not prepared. (For the concerned, no, I am nowhere near the danger zone. Though I have friends who are.) I hope the state agencies are better prepared then they were for Mount St. Helens, because this is going to be a whole lot worse.

I just hope "eventually" can hold off on getting here until those threatened can be better prepared. But maybe this will just turn out to be a brief scare that can encourage such preparation.

geonuc
2016-Jul-31, 12:28 PM
I did some analyzing of earthquake data from 2009 to current and it does seems to be hinting the the middle magma chamber is not under the mountain directly, but off to the west side. Lateral vents and chimney's are not that uncommon. Mt. Tabor, most cinder cones, are examples of that.

The mechanisms for magma moving laterally more distance, when there is less surface above it, would be a pre-existing fault, weakness, cave system, or underground river system.

My guess with Mt. Rainier is it was a fault.

Attached some plots of events since2009.

I marked up the overhead map with extrapolated features. The Red Zone being the upper portion of the Middle magma chamber, which feeds through a weakened fault area marked blue, to the Volcanoes upper chamber/chimney in green. The black area is an extrapolation of the lower end of the Middle magma chamber. The Smaller black inner circle is the probable injection site from below.

The purple marked area, are sub-vents, which lead to cider cone fields. The middle one feeding Cowlitz Chimneys/Tamanos Mt. area. The Upper one feeding the Skyscraper Mt./McNeely Peak/Mt. Freemont area. And the south one feeding to the Tatoosh Wilderness, directly under it's highest peak..

I drew those features before looking at the Tomography of the area, which seems to support, a little bit, what I had come up with.

Source The College of New Jersey: http://physics.pages.tcnj.edu/files/2014/07/mt-rainer.jpg
Good work. If you're correct, it seems there's a decent chance that the next major eruption may not be from Rainier itself but from the western slopes of the volcano. If magma pressure builds and the conduit(s) from the upper chamber to the historic throat of the volcano becomes too restricted, the weak point may be directly above the chamber. Or somewhere laterally nearby.

Squink
2016-Aug-02, 11:06 PM
So, sort of in a Seattleish direction if the big mountain exit gets plugged.

LookingSkyward
2016-Aug-02, 11:37 PM
More like Tacoma - Lahar map link:
http://www.washingtonstatesearch.com/Washington_maps/Mount_Rainier_Hazard_map.html

Trebuchet
2016-Aug-03, 05:06 AM
Would have been a little more toward Seattle if the White River (https://en.wikipedia.org/wiki/White_River_(Washington)) hadn't changed course 100 years or so ago.

bknight
2016-Aug-03, 12:56 PM
Any eruption in the area will be short term devastation to the environment, just like Mt. St. Helens did.

Trebuchet
2016-Aug-03, 02:50 PM
Any eruption in the area will be short term devastation to the environment, just like Mt. St. Helens did.

But far more devastating to human activity, even if there's enough warning for for a full evacuation. The town of Orting (https://en.wikipedia.org/wiki/Orting,_Washington), for instance, is built on a lahar plain. IF it gets buried under feet of steaming mud isn't at issue, it's simply a matter of when. And according to that article, it would take only 30 minutes for one to get there. They've installed an extensive system of warning sirens, with automatic sensors. Some years ago, one of the sensors malfunctioned and the sirens went off. The schoolchildren would all have survived, because the teachers took the correct action and evacuated to higher ground. But many of them would have been orphans because pretty much nobody else in town did anything.

bknight
2016-Aug-03, 03:24 PM
True and the people that refused to leave the danger zone prior to Mt. St. Helens eruption. There are always some that ignore the warnings and suffer the consequences of a real event. I wish the people good luck in the general area, but hope they get to safety when this one blows.

KaiYeves
2016-Aug-03, 06:13 PM
True and the people that refused to leave the danger zone prior to Mt. St. Helens eruption. There are always some that ignore the warnings and suffer the consequences of a real event. I wish the people good luck in the general area, but hope they get to safety when this one blows.

The "danger zones" drawn up by government officials prior to the 1980 eruption were actually far closer to the volcano than the geologists wanted because of various political and commercial factors. Many of the survivors interviewed in Richard Waitt's In The Path of Destruction were actually outside of the official danger zones but of course still in the natural ones and ended up receiving serious injuries. There were also people who entered the restricted zones despite warnings and guards to see the volcano up-close, though, as well as Harry Truman, who famously never left.

danscope
2016-Aug-04, 02:00 AM
When you have a directed lateral blast , like Mt ST Helens , that area in line with the blast extends out beyond a
stationary vertical column . Hard to tell which side blows out.

geonuc
2016-Aug-05, 07:49 PM
According to the USGS, Rainier is different than St Helens. Rainier's magma tends to be less sticky and produces fewer pyroclastic flows. So, Rainier is probably not going to do an explosive, mountain-busting eruption like St Helen did in 1980.

Trebuchet
2016-Aug-05, 09:50 PM
According to the USGS, Rainier is different than St Helens. Rainier's magma tends to be less sticky and produces fewer pyroclastic flows. So, Rainier is probably not going to do an explosive, mountain-busting eruption like St Helen did in 1980.

I guess that's a relief. And perhaps why it is so much bigger. The real worry is the lahars.

CJSF
2016-Aug-05, 10:28 PM
That's been the nearly constant call throughout the past several decades regarding Rainier: mechanical and chemical erosion and eventual collapse of the mountain's sides and glaciers resulting in destructive lahars.

CJSF

dgavin
2016-Aug-10, 02:22 PM
A small swarm of quakes, 19 total so far at Rainier over the last week. 7 within the mountain, near .5 - 1.5 km surface, all strike slip events. On the south/east side 2 Volcanic quakes in the general location of the possible Tatoosh Wilderness feeder vent I had identified above. The rest were all strike/slips and followed the region of the deeper magma pocket.