ATS Exclusive- Could Deep Well Injection Trigger a 7+ Earthquake?

reply to post by Labrynth2012


Your statements seem extremly ignorant. Just because your fracking horizontally doesn't mean that it's not going to have an effect on the earths crust. Your still thinning out the layers making it more suceptable to preasure from both sides. If you work in the oil industry you might wanna know you've been doofed about what fracking does to the earth. Use your head and a little bit of common sense, and as always, deny ignorance.

As to you trueameerican I appriciate the hard work, and actually thought about clapping to the aplause. It's finally nice to hear some good news that the govt. is denying the money what they want. Stay Tha FAAAACK outta yellowstone!!!!!!

I take no offense, Here's a picture of what I believe happens. It works sort of like a car windshield. You get a rock hit, a star, and over time a crack migrates across the glass. Suppose it hits another crack, now you have effectively doubled the Crack/Fault. There still needs to be much study of this phenomenon, and I'm sure both sides of the argument will introduce data reflecting their particular goals.
www.what-is-fracking.com... The cross sectional view is pretty self explanatory, and despite being horizontal or vertical, when the frack cracks meet a juncture of a fault, you now have considerably more structure that is subject to movement.......... ie. fault failure or what we call earthquakes.
But, a hundred years from now.....well we will reap the reward of our ignorance, and likely much sooner.

I hope this isn't the case. We'll find out soon enough here in Southern Colorado. Shell is going to begin fracking for natural gas deep within the great dikes of the Spanish Peaks.

The dikes were formed when fissures filled with molten material. Shell plans on fracking right down into the heart of them. I can't believe they really know what they're doing. It's being reported here that Shell has only a limited study in hand but got the green light anyway.

We've already had one of the strongest earthquakes (5.3) I've ever felt back in August of last year. The epicenter was in the area of an ongoing fracking operation.

reply to post by openeyeswideshut


i agree. if you work in that industry they are going to make sure you have no doubt that drilling, etc. is safe. they don't want the people doing all the work ever thinking what they are doing could cause major problems.

Originally posted by pasiphae
reply to post by openeyeswideshut

 

i agree. if you work in that industry they are going to make sure you have no doubt that drilling, etc. is safe. they don't want the people doing all the work ever thinking what they are doing could cause major problems.

Well believe it or not, professionals and scientists in the industries of geothermal energy, as well as many others, including the US Dept. of Energy, actually ARE concerned about induced seismicity from these processes. Because it does, and can affect residents- and does pose a certain risk. And one reason it helps to make friends with pros, is they can point you to documents you would probably never find on your own. And that is what happened in my case.

I have received in depth comments from one of my professional contacts, who is someone I greatly admire, regarding this exact subject of induced seismicity at The Geysers. And this includes a comprehensive scientific study, which is even somewhat readable! It confirms a lot of what I have uncovered on my own about this, but is much more comprehensive, and includes even more seismicity and further information on faults and detail and extent of areas affected.

What their comments and the study does not confirm is the potential for the shallower seismicity to trigger a larger fault rupture, which is the question asked in the thread title.

Could Deep Well Injection Trigger a 7+ Earthquake?

So far there does not appear to be any direct evidence of this, and here are my contact's direct comments about it:

They were not reporting less than M4.0 earthquakes before 1970, so there is no good way to know how many small earthquakes there were. After they started injecting and greater withdrawal, the companies were asked to start monitoring more closely, the USGS increased their coverage, and LBL/Berkeley put in a network. So it is a VERY closely monitored area post-1970, and the monitoring quality progressively increased with time. I'd guess that the current threshold of detection stabilized in 1990 or so, so you can compare data easily thereafter. In any case, you are correct that there is no doubt that seismicity has increased with production and injection. I guess the real question is whether this actually increases the seismic risk for anyone in the region. Many people think not, which is why development continues.

This person has directed me to the following scientific study on the matter, stating:

The following is a pretty good summary of what we know:
www.eere.energy.gov...

It is 12 MB in size.

As you can see, there are lots of people who have followed the situation and much research has been done. This is not a subject that has been ignored.

At Yellowstone, my worry would simply be that geothermal development would ruin the thermal features. I am not so worried that it would induce powerful earthquakes or start a volcanic eruption. Fortunately, we won't need to find out, because geothermal development is extremely, extremely unlikely.

They also comment this:

My understanding is that the long-term risk from big strike-slip faults is not perceptibly different at The Geysers than it is elsewhere along those strike-slip faults. My impression from the reading I've done over the years is that any increased seismic risk posed by energy extraction at The Geysers is minimal.

There are no "risk-free" energy sources. They all have their warts. Geothermal energy is one of the least polluting and most green. Even solar and wind have their hidden costs.

The USGS summary of seismicity at the Geysers on the EHP FAQ site is:
earthquake.usgs.gov...

But what is not so obvious until you actually dig in to these documents, is that the RATE of 4+ magnitude quakes in The Geysers area has increased, noticeably and substantially. I would never have probably known this, or obtained these documents without professional guidance. I discovered the 4+'s on my own, and was surprised, but didn't see the rate increase until I read the docs.

The docs themselves also confirm inconsistencies between published data on faults, and published data on the extent of seismicity. It is even more than I was able to uncover with my own findings. The study includes some data not available anywhere else. So read the links and become informed, if the subject interests you.

But how many more 4+ magnitude quakes are going to happen before this gets too far out of hand? And who is going to pay if all this induced seismicity and injection DOES trigger a bigger quake down the road that causes substantial destruction? Area residents, that's who.

Hey wait a minute. I got to thinking about this more, and so I put forth the following commentary and questions to my contact. Hate to quote myself, but just trying to keep everyone in the loop here:

Given the increase in rate of 4+ seismicity, shown by the studies, it would seem to me that previous, bigger, tectonic quakes along the area faults have also occurred at shallow enough depths to make me raise again the question of potential triggered tectonic rupture from injection induced seismicity. I can infer from these documents that the depths of the induced quakes could be close enough in depth to aggravate existing fault points near similar depths that have shown tectonic, shallow rupture before.

Do you know to what depths compressional or shear wave energy can reach from a 4.5 Mw at say 5 km depth, downwards? Aren't there limits to that? Isn't some or most of the energy reflected back off of deeper crust layers? And that essentially, at some depth point the tighter packed layers, under much greater pressure, have enough rigidity to repel the energy generated from above? Seems like I have witnessed this a bit with very shallow sub mag 2 quakes, where the sub 2 Hz frequency response of instruments is noticeably less. I suspect this kind of condition for the shallow quakes that happened in Clintonville, WI, for example.

But still, if it could be shown that enough of this energy propagation was reaching known focal depth points of larger tectonic quake hypocenters, then I don't see why at all that triggering would be out of the question. To me it would be entirely possible. Especially if the orientation of the injection induced focal mechanisms were such that they propagated particularly harmful energy into a tectonic focal point at a similar depth. Didn't Denali into Yellowstone illustrate pretty clearly what can happen when the worst kind of energy is directed through focal mechanism orientation?

So I will be curious to see what response if any that draws.

lol, yeah I got a response- and I quote:

"Keep thinking the big thoughts, TA!"

And that was pretty much it.

So that's where they are going to leave me? Guess they didn't have too much of an answer? Was I not making enough sense? Dunno. But looks like that is where this is going to get left, for now.

Even though I believe I have actually just shown a potentially valid scientific mechanism for the triggering of a 7+ tectonic rupture to occur, with my argument above, and the facts presented in this thread.

And I will now rest my case. It might go to sleep, but if it awakens one day, I believe the evidence for its potential was there all along. Surely some noob like me wasn't the first to point this out.

TA: Great thread! And my hometown made your map! Woo Hoo!

I grew up in Cloverdale, CA through the 70's and 80's. Many friends' parents worked at the Geysers, and many of those old classmates work up there today. I'm going to throw some pros and cons against the wall for your consideration, but for the record I agree that induced seismicity definitely occurs at the geysers...I have friends on the hill who feel the shaking!

First off: That fault system has been active for quite a while, pre-dating the geysers injection processes. While there is no doubt that induced seismicity occurs at the geysers, the geologic conditions of the area prohibit anything more than a 5.0 on the Richter scale. This is due to two things:
First, The geysers sit above a near-surface magma chamber, roughly 5-6 km below the surface. This depth limit prevents the large scale buildup of tensions that cause major earthquakes. The magma chamber also heats the rocks. When rocks get hot they lose structural integrity... become less brittle and more viscous. This state also works against large energy buildup. Soft rocks fail at much lower energy levels than brittle cold rocks.
Second, none of the faults in the Geysers area are significant enough to produce a notable earthquake. The region is crisscrossed with a jumble of small faults, but none have any impact on large scale geologic activity.

As for injection history:

The geysers began the reinjection process in 1970, recycling "spent geothermal fluids" back into the production zone. While I don't have figures on volume, I imagine it wasn't an amazing amount.

After a peak in production around 1987 (~1.8 mil homes powered), the volume of geothermal fluids began a steady decline. They were running out of steam, literally. In 1995 a pipeline project began ( Lake County-Southeast Geysers Effluent Pipeline Project) which transported 8 mil gal / day of greywater to be reinjected into the production zone. That project was considered successful, and, in 2003, the Santa Rosa Geysers Recharge Project began operations, transporting 11 mil gal / day to the geysers as well.

As for personal anecdotes:

I knew several Lake County residents in the town of Cobb, who firmly believed that earthquake activity rose once the wastewater injection programs began pumping. Some folks even went to court due to structural damage to their homes from the repeated earthquakes. Don't know how that turned out, exactly.

As a geologist:

Makes perfect sense that a) the slow depletion of fluids from the reservoir would yield less seismic activity (located above the magma chamber, the rocks are much less brittle than comparable rock in the larger area, bending rather than fracturing) and b) the sudden injection of large fluid volumes would cause an increase in quakes, as the strata would have zero time to adjust to the changing forces (less brittle, but not taffy).

So TA: I would focus more research on the changes seismically in those key years where large-scale injections began, 1995 and 2003. That would certainly show some definitive proof that when conditions changed earthquakes ensued, although you may find that the work has already been done

As for the "Save the Planet!", "Fracking is the Devil!" folks...
It's an issue that really comes down to numbers and the stark realities of living in a larger society. The impacted residents might total several thousand, while the Geysers facilities provide power to 1.1 million people (and has for decades), pretty much the North Coast all the way to Oregon. Shut down the geysers and not only do you have a HUGE energy crisis, you also get back a couple pretty damn big wastewater disposal problems as well.

Sources:
www.geysers.com...
esd.lbl.gov...
en.wikipedia.org...

Hmm, wrote back, not sure what they meant. They answered back:

"It was a compliment :-)"

And that was it. So I guess I appear to be making some kind of sense anyway... Weird. No rebuttal from a respected scientist, and instead a compliment! ok... Thanks!

So, any other takers that can give me a good reason why these quakes couldn't trigger tectonic quakes if badly focused energies due to larger magnitude, induced seismicity were directed into closely located faults, with known previous ruptures at similar depths? Because I believe that is indeed the situation that is present at The Geysers.

So have there been larger, tectonic quakes in the past on area faults of shallow depth enough to provide evidence that local faults can rupture at shallow depths? Take a look for yourself. This data I found from a site listing historic quakes just back to the early 70's from Middletown, very close to The Geysers:

www.homefacts.com...

Data for the surrounding towns shows similar. Sort by magnitude, and look at all the shallow depths of the biggest quakes. I also pulled data from the NCEDC itself and found the same. I will concede though that I haven't managed to find a 7+ yet, directly in the area. But historic records of these only go back so far it appears, into the 1800's. Another perspective on that yet still, is the very lack of quakes itself might be a red flag, in that immediate area, which is ripe with faults. It appears one may be due there anyway. 95%+ percent probability of a 5+ in next 50 years, the sources say.

Anyone on the opposing side of this argument is still going to have deal with the reality that Northern California has had a lot of tectonic quakes at very shallow depths, less than 20 km deep, some extremely shallow, less than 5 km, and well within reach of induced 4+ activity- and within 120 km of The Geysers.

And if we are talking about relatively small differences in depth, the question then becomes if 4-5 mag induced quakes have enough propagation energy to affect subsurface areas
slightly deeper. Well why couldn't they, if the depths of the very shallow tectonic quakes are right near the same depth of the induced seismicity? I just showed that the faults are there, and have the Mw capacity of 7+ due to fault length and seismic moment rupture typical of other quakes of that size. All that's in the OP. In addition, unknown extension faults of that key thrust fault alone could increase the Mw even further.

I guess for a more definitive answer on that, going to have to consult the books and/or the pros. Because to me, there is enough evidence now that a 7+ could be possible from triggered, induced seismicity. The faults are there and the trigger is there, pounding away.

The USGS FAQ page regarding seismicity at the Geysers echoes what ATS member blamethegreys posted above.

It is possible that a magnitude 5 could occur, but larger earthquakes are thought to be unlikely. In order for a larger earthquake to occur, it is necessary that a large fault exist. For example, the 1906 magnitude (M) 7.8 San Francisco earthquake ruptured nearly 300 miles of the San Andreas Fault. At The Geysers no such continuous fault is known to exist.

I suppose an unknown subsurface fault, large enough to produce a mag 7 could exist--we don't have all the information yet regarding the geologic situation anywhere, not even California.

If I were a resident near the Geysers, I would worry more about the large Sulfur Bank mercury mine on the west side of Clear Lake & its associated contamination, but that is a topic for a different thread.

Regarding seismicity, a Mag 7+ rupture of the nearby San Andreas is a threat the local residents should be preparing for.

Well considering that I can't seem to get any more information on the thrust fault that runs RIGHT DOWN THE MIDDLE of all this induced seismicity, let's say I just put that one on the back burner for now, even though that in itself is of considerable risk.

But working with what data is available, there may be an even bigger concern: the Maacama fault segment. It is 90 km in length, a mere 8 to 10 km from all the biggest induced 4+ seismicity, and particularly troubling because it is a fault segment. Fault segments often rupture near their entire lengths, whereas normal faults rarely rupture across their entire lengths. Japan 9+ was one such rare case, sort of, but that may have had more to do with an inaccurate assessment of total fault length due to unknown extensions which reared their ugly head March 11, 2011.

The bottom line is when I plotted the Maacama fault segment into GE, and plotted seismicity from 1973 to 2004 at the Geysers on top of that, a pattern emerges which I believe could be used as evidence if that fault segment decides to let loose.



The red box shows how this activity is spreading southwestward, directly towards the Maacama fault segment. The red circles show earthquakes on the Maacama fault itself. And all of this since 1973. Has the Maacama fault segment already started reacting to this induced injection seismicity?

At 90 km surface length, subsurface rupture length of the Maacama would not be unreasonable at 110 km, and could actually be much higher than that. Some quakes can show a ratio as high as 1:3 or more of surface rupture length to subsurface rupture length, which would put a worst case scenario at 270 km subsurface rupture x 25 km width = 6,750 square km. That would be highly unlikely, but would yield a massive earthquake of well over 8 Mw, if average displacements were high enough. And they probably would be with that high a total rupture area. A more likely scenario would be 110 km subsurface rupture x 15 km width = 1,650 square km rupture area, with an average displacement of .8 meters, which would be about a 7.2 Mw earthquake. Or a 100 km subsurface rupture x 20 km width= 2,000 square km with an average displacement of 1 meter. That would be a bigger one, about 7.7 Mw or so.

But these ratios vary substantially. For example, the 1992 Landers, CA quake had a total rupture area of only 744 square km's. However, because the average displacement was a whopping 2.95 meters, the quake yielded 7.6 Ms (7.3 Mw ) magnitudes with ruptures of 71 km surface, 61 km subsurface, 12 km width, and maximum displacement of 6 meters. See event 240 in the scientific study linked in OP.

The bottom line is that again, the faults are there, close by, and the potential for larger, injection induced seismicity to trigger one of these faults at The Geysers is most certainly there. And it may already be happening. Again, see the pic in this post.

One of the inherent flaws in your argument is that this area doesn't contain traditional faulting. The north coast is the remains of Mesozoic accretionary wedging. The faults run steep but shallow: They are "surface" features, rather than deep, plate-impacting faults.

That combine that with the geysers' magma chamber only affecting a few kilometers of the faultlines makes it very hard for me to believe that there could be any large induced events. Impossible, no. But likely? I would be very surprised it could happen. Perhaps in conjunction with a very large San Andreas event...

Here's a geologic map of western Sonoma County. Notice the cross section at the bottom. It illustrates the accretionary wedging I spoke of earlier. pubs.usgs.gov...

Here's a hard-to-read geologic map of the field itself from 1974. www.osti.gov... for your perusal.

Hey TA, I'm not sure how relevent this data is, but I'm throwing it out here.

While perusing GPS data, I found this station showing a deviation from its normal trend, P203, which is just a few kms. East of the Maacama fault.
image from USGS

Here is the data (1st image is raw, 2nd is cleaned):

(click for larger image)

To me, it looks like there could be some tension building in this local vicinity, because none of the surrounding stations are showing similar movement. (click the "Nearby GPS Plots" link on the P203 page above)
And, since it has been accelerating westward for over a year's time, I don't suspect this to be a malfunction.

This fault map of California does show an older East-West trending fault near this monument; maybe that is where this westward push is coming from?

Anywho, thought I would share...because when I have found deviations from the norm in the past, earthquakes often follow.