Pretty Serious Swarm at Long Valley right now, Intensifying- 3.9, 3.8, 3.2

a reply to: Olivine

MLAC or MLC?

I see MLC, but not MLAC. Give me a network with the station, please.

a reply to: TrueAmerican
CI.MLAC..BHZ sorry Mammoth Lakes through the southern california network

originally posted by: Olivine
Out of curiousity, what does the spectro look like of this low amplitude "stuff" beginning at 15:11 UTC until about 15:14?
(I'm looking at MLAC in GEE--nearest live seismo I've got access to)

Just background noise?

Yep, got spectro on that, now that you gave me the network/station/channel, and it is noise.

a reply to: whatnext21

It looks like there was a data "drop out" for whatever reason, and the long loops are the instruments getting back on track.

The blue one seems to coincide with a Mag 3.5 overnight. That station is on the west side of the southern Sierra Nevada (southeast of Fresno) and noisy as heck--although good at picking up small quakes from LV. It must have very high sensitivity settings employed.
When there wasn't much earthquake activity in the past, I've tried to decipher what is going on there. Large farm equipment nearby is my hunch.


ETA:
a reply to: TrueAmerican

I suspected as much--thank you, sir.

a reply to: Olivine

What if it's a shift in ground water, similar to what could happen with a glacier but in underground aquifers.

Ground water depletion and lower lake levels may cause land subsidence and a shift in aquifers, like an underground landslide.

Disclaimer: I'm a wannabe geologist who likes to speculate

Thanks again for keeping us informed

a reply to: Observationalist

It could be, I suppose. We can't see what's going on underground directly, and water can play an important role in seismicity, but there is magma near the surface, as evidenced by the fumaroles and hot springs in the area.

Here is a short article from the L.A. Times published about an hour ago.

The recent swarm of quakes in and around the mountain is being tied to recent "volcanic unrest" marked by gas emissions and tree die-offs believed to be related to sheets of molten rock intruding upward and cutting off root systems, according to the USGS.

It is unclear whether the latest round of quakes is linked to the volcanic unrest, but USGS spokeswoman Susan Garcia said the region is "pretty active."

a reply to: TrueAmerican

Trueamerican, they are related. it is the only part where I disagree with you. The earthquake activity has intensified since the Earth's magnetic shield has been weakening and changed the rate of weakening in the last 7 months.

The Earth's magnetic field is weaker now because there are massive changes occurring on the Earth's core. We know that underwater volcanos are heating many parts of the oceans, including the Antarctic. If you look at a map of the land volcanos that are erupting right now, there are many.

All this activity is related to the recent changes that we are also seeing on Earth's magnetic field.

Scientists probe link between magnetic polarity reversal and mantle processes
by Staff Writers
Liverpool UK (SPX) Aug 03, 2012

Scientists at the University of Liverpool have discovered that variations in the long-term reversal rate of the Earth's magnetic field may be caused by changes in heat flow from the Earth's core into the base of the overlying mantle.

The Earth is made up of a solid inner core, surrounded by a liquid outer core, in turn covered by a thicker or more viscous mantle, and ultimately by the solid crust beneath our feet.

The magnetic field is generated by the motions of the liquid iron alloy in the outer core, approximately 3,000 km beneath the Earth's crust. These motions occur because the core is losing heat to the overlying solid mantle that extends up to the crust on which we live.
...
Dr Andrew Biggin, from the University's School of Environmental Sciences, said: "The magnetic field has undergone big changes in its behaviour that might be due to the mantle's controlling influence on the core.

In particular, we focused on the time interval between around 200 and 80 million years ago - when dinosaurs were still around - when the magnetic field initially started reversing its polarity very frequently. During this period the polarity was reversing up to 10 times every million years; however 50 million years later, it stopped reversing altogether for nearly 40 million years.

"When these changes in the magnetic field were taking place, the whole of the Earth's crust and mantle, including all of the continents, were undergoing a big rotation with respect to the geographic and time-averaged geomagnetic poles - the points defining the Earth's axis of rotation.

"We suspect that this process, called True Polar Wander and caused by the changing density distribution in the mantle, will have changed the pattern of heat flowing out of the core in such a manner as to cause the magnetic field to first become less stable, with lots of reversals, and then become much more stable - and stop reversing."
...

www.terradaily.com...

Plate tectonics may control reversals in the Earth's magnetic field

Oct 24, 2011

The Earth's magnetic field has reversed many times at an irregular rate throughout its history. Long periods without reversal have been interspersed with eras of frequent reversals. What is the reason for these reversals and their irregularity? Researchers from CNRS and the Institut de Physique du Globe, France, have shed new light on the issue by demonstrating that, over the last 300 million years, reversal frequency has depended on the distribution of tectonic plates on the surface of the globe. This result does not imply that terrestrial plates themselves trigger the switch over of the magnetic field. Instead, it establishes that although the reversal phenomenon takes place, in fine, within the Earth's liquid core, it is nevertheless sensitive to what happens outside the core and more specifically in the Earth's mantle. This work is published on 16 October 2011 in Geophysical Research Letters.
...
In conclusion, the degree of asymmetry has varied at the same rhythm as the magnetic reversal rate (number of reversals per million years). The two curves have evolved in parallel to such an extent that they can almost be superimposed. In other words, the further the centre of gravity of the continents moved away from the equator, the faster the rate of reversals (up to eight per million years for a maximum degree of asymmetry).

What does this suggest about the mechanism behind geomagnetic reversals? The scientists envisage two scenarios. In the first, terrestrial plates could be directly responsible for variations in the frequency of reversals: after plunging into the Earth's crust at subduction zones, the plates could descend until they reach the core, where they could modify the flow of iron. In the second, the movements of the plates may only reflect the mixing of the material taking place in the mantle and particularly at its base. In both cases, the movements of rocks outside the core would cause flow asymmetry in the liquid core and determine reversal frequency.

phys.org...

We are living in a time when Earth's magnetic field is changing in ways which hasn't occurred in well over 800,000 years at the same time that volcanic activity is increasing, including underwater, as well as seismic activity. The evidence seems to show they are related.

I've always read that a swarm means it's letting off pressure a little at a time as to prevent the big one.

a reply to: Staroth

I've heard the same, however also heard could be foreshocks to something greater.

Time will tell. I've been checking in frequently last few days to USGS. This is a good swarm.. definitely deserves attention.

Well, this is only tectonic activity according to the news release on the CalVO front page.

The earthquakes themselves are small, brittle-failure (rock breaking) events. Such events are sometimes called "tectonic." The earthquakes do not result from the underground movement of magma.

I would think they would have included the modifier, "so far"....

can we speak of an "bounching" core ????
an kind of instability ???

originally posted by: NarcolepticBuddha
a reply to: TrueAmerican
Forgive my ignorance, and I AM speaking from a position of ignorance...

Aren't quakes in the 3.0-3.5ish region barely perceptible?..the kind of quakes most people don't notice and/or sleep right through?

I just always wonder why people look at these little quakes as anything other than the Earth just doin' its thang. In my region, we get little swarms of this magnitude every so often and it's no big deal.

I guess what I'm asking is..why is this a "pretty serious swarm?" Sorry, it's just something I've always wanted to ask people who look out for 'quake activity.

Nah, you're right. I hardly ever feel anything less than a 5 magnitude 5.5 plus are the good ones!

I guess that from what I remember that after a 7 or 8, every 1.0 mag added is double the explosive feel of the shake. Not quite sure, so don't qoute me on that.

I have experienced a many 6-7s throughout my life in Alaska. What a privilage it was....just no floods please, I'm scared of the water.

a reply to: AK907ICECOLD

Thanks for your input. Because no one else provided me with an answer, I'll have to remain ignorant on why little quakes are significant

a reply to: NarcolepticBuddha

I've felt a 2.6 and a 3.9 woke me up.

This swarm could be a prelude to a larger quake or they could not be. Usually when small, quakes like this swarm, it's good to stay aware.

Here is an article from LA times. Largest swarm in a decade.
LINK

Found this and that...

Just adding.

Mammoth earthquake swarm is the largest in nearly a decade
www.latimes.com...

Interesting times.
Stay safe everyone.
Great thread too, very informative. Good work.

A tribute to this on-going thread.

originally posted by: Olivine
Well, this is only tectonic activity according to the news release on the CalVO front page.

The earthquakes themselves are small, brittle-failure (rock breaking) events. Such events are sometimes called "tectonic." The earthquakes do not result from the underground movement of magma.

Yeah, and I got a piece of waterfront property in Acapulco I'll sell you, too.

That's what they said trying to explain the 2008 Lake Yellowstone swarm too- and like years later a study concluded it was more likely a magmatic intrusion that caused the swarm.

Now seriously folks- 600 quakes occur right on top of a resurgent lava dome, in the middle of one of the biggest active volcanoes on earth, and I am to believe that all of a sudden 600 pieces of fault decided to break all at once so a scientist could call it "tectonic"? So that then in a year or two another little blurb appears buried on a website somewhere saying that a study concluded it was magma at fault?

Umm no. HELL NO. We been there done that already. Tectonic my ass.

originally posted by: TrueAmerican

originally posted by: Olivine
Well, this is only tectonic activity according to the news release on the CalVO front page.

The earthquakes themselves are small, brittle-failure (rock breaking) events. Such events are sometimes called "tectonic." The earthquakes do not result from the underground movement of magma.

Tectonic my ass.

ROFL!!!!

Good one TA!

Now all I can think of is a gang of seismologists getting ready for a gang fight and one of them saying:

"We're about to get tectonic on your ass!"

a reply to: eriktheawful

Yeah, well let em get tectonic. I'll go Super Plinian VEI 8.

Update:

Things are calming down finally. Still the occasional quake, but much less than before. So it is probably close to over. But that's what I thought when the first small swarm died down to nothing. 10 hours later, the second small swarm started, and then intensified into 600+ quakes. There is just no telling what to expect next. I be a watchin.

a reply to: TrueAmerican

I had a laugh when they said trees and root systems being cut off. That is just shear stupidity. This is definitely the end of days. The world is about to see the worst war in human history in the middle east. The Sun has gone quiet and the world is about to pop big time, where is the question. I bet the people at the USGS are not gonna be getting much sleep with this and Yellowstone rumbling.

Uplift is bad. I don't care how they twist it. Did you see any harmonic tremors in this mix or did they not show that info?