There are several examples around the worlds and there is a large scientific literature focusing on this topic. Small earthquakes are more common than expected near wells that are used for injecting waste fluids from fracking, as well as from other processes, including oil extraction and geothermal energy production. However, the vast majority of triggered earthquakes are too small to cause any damage. Moreover, just last year I have studied the M5.1 earthquake occurred close to the city of Lorca and I found evidences of possible triggering.....

If you are interested, please give a look at: http://www.nature.com/ngeo/journal/v5/n11/full/ngeo1610.html or download the paper from my profile.

Icaro wrote " medium (and also large) scale magnitudes cannot be triggered by such activities. It requires large amouts of energy..."

I would suggest that the energy is already there. It is the lubrication provided by wells that allows that energy to be released.

I suggest also this very interesting comment of Prof. Mark Zoback (Stanford University, USA):

http://www.pnas.org/content/early/2012/06/13/1202473109.full.pdf

Thank you Mimmo for your interesting contribute.

earthquakes can trigger oil production

And here there is another interesting paper focusing on Induced-seismicity:

http://www.sciencemag.org/content/341/6142/1225942.full

Hello,

three other articles on the subject have been published in Science along the last one that Mimmo posted:

Anthropogenic Seismicity Rates and Operational Parameters at the Salton Sea Geothermal Field

Emily E. Brodsky, Lia J. Lajoie

http://www.sciencemag.org/content/early/2013/07/10/science.1239213

Enhanced Remote Earthquake Triggering at Fluid-Injection Sites in the Midwestern United States

Nicholas J. van der Elst, Heather M. Savage, Katie M. Keranen, Geoffrey A. Abers

http://www.sciencemag.org/content/341/6142/164.abstract

and

Some Earthquakes Warn That They Are About to Strike

Richard A. Kerr

http://www.sciencemag.org/content/341/6142/117.summary

Finally, Avouac wrote a news and views to introduce Mimmo's paper in 2012, I haven't compared the bibliographies, but there might be a couple additional references here:

http://www.nature.com/ngeo/journal/v5/n11/full/ngeo1609.html

cheers,

Luca

Oil & gas production; geothermal water injection for ex. in Enhaced Geothermal Systems (EGS); fraking. All those should be considered as different industrial and physical projects and different are the geological conditions around the world. While mix everything?

An example of interest for the Poncia: the geothermal water re-injection in the reservoir near the city of Ferrara (Casaglia plant) and not far from the Emilia clouds of earthquakes, hasn't triggered earthquakes, nor small, as observed after several years by a dedicated seismological observation net.

Other EGS sometimes produced large earthquakes (see publications in http://www.iea-gia.org/publications.asp. and: Majer, E., Baria, R. and Stark, M. (2008). Protocol for induced seismicity associated with enhanced geothermal systems). The first industrially-generated earthquake was observed after water re-injection from a nuclear power plant and at large distance from the site.

Other examples (i.e. oil production in Columbia) show that earthquakes are followed by increased pressure in the reservoir. Of course the geological conditions (i.e. nature and physical rock properties, tectonic setting, ...) are determinant.

Interesting discussion, is there a technical reference for pressure increasing following an earthquake, as noted in Columbia?

Im no expert on this but i believe some processes (fracking) can cause minor tremors. It occurred around Blackpool UK when fracking operations started. But it must be stated that there is a big difference between tremors and earthquakes.

I am the Technical Director of Rivara Gas Storage srl, the (successor to the) company that in 2002 proposed the Rivara undergroung gas storage project in a geological structure located within the area hit by the multiple earthquake of summer 2012 in Emilia (see www.rivaragasstorage.it).

A lot has been said in local pubs or equivalent (called Bar in Italian) and written in local newspapers about the possible relation between the Rivara site and the earthquakes. We even received emails from infuriated citizens asking why we made the earthquake and complaining for the damages.

This must be the first case ever that applying for a permit to use a geological structure for undergroung gas storage caused/triggered/anticipated a major earthquake! The permission to start the project has not granted, no wells has been drilled and no gas has been injected underground, as repeated over and over even by the local opponents to the project.

The documentation officially submitted to the national authorities in charge of the Environmental Impact Assessment of the project include numerous technical reports demonstrating that 1) initial 3D geomechanical modeling shows that the project is not dangerous and that the strain on the surrounding rocks, even individual fault planes, is insignificant, and that 2) the cap rock has mantained its tightness for millions of years in spite of million of years of strong earthquakes. Additionally, the submitted documentation explains which geomechanical parameters are important, what is known now and what needs to be appraised with new measures, and how those new measures are going to be taken.

In spite of all this, unjustified fear prevailed and spead wildly on internet and in political circles. Probably, only time will remedy this anti-scientific craze.

As my long carrier on oil field (gas and oil well drilling) I can not belief that they can trigger earthquakes.

No, Oil well does not induce EQ.or in general ,No wells can induce EQ. But any physical disturbance inside the well can induce an EQ , if the well is located in a Fault, and this will be of very very low magnitude.

The term “triggered seismicity” refers to those earthquakes caused by man’s engineering activities that alter the state of stress/strain in the Earth’s crust. Triggered earthquakes, though characterized by low-to-moderate magnitude, have significant social and economical implications since they occur close to the engineering activity responsible for triggering them and can be felt by the inhabitants living nearby and may produce damage. The first documented example of triggered seismicity was observed in 1932 in Algeria, when a shallow magnitude 3.0 earthquake occurred close to the Oued Fodda Dam. Since then, thanks to on-going increase in seismic networks for monitoring purposes, numerous other examples of human-induced earthquakes have been identified. Triggered earthquakes are related to a number of human activities, such as fluid injection under high pressure, deep underground mining, oil recovery, construction, waste disposal, dams, geothermal power generation and groundwater extraction (Zoback, M., 2007. Reservoir Geomechanics. Cambridge Univ. Pr., pp. 449). The largest accepted example of a triggered earthquake was the 15 October 1979 magnitude 6.6 earthquake in Imperial Valley, close to the Cerro Prieto geothermal field (California). Several studies carried out in the last decades have evidenced that triggering of earthquakes are closely related to the changes in pore pressure which is capable of altering the stress state and reducing frictional resistance on nearby faults, thereby encouraging the faulting.

Although only a small fraction of human activities among the hundreds of thousands of sites in the world have induced seismicity at levels that are noticeable by the public, understanding the potential to induce felt seismic events in order to limit their occurrence and impact is desirable for government agencies, industry as well as the community at risk. Hence, it is important to ascertain the possibility of earthquake triggering in proximity of densely populated areas for a correct evaluation of seismic hazard.

In Italy, induced seismicity is suspected to have contributed to the disaster of the Vajont dam in 1963. Recently, induced seismicity is suspected to have contributed to the 2012 Emilia Romagna earthquake also. From my personal point of view, without extensive researches which take into account several aspects (faults array, ground deformation pattern, state of stress/strain on the fault array and surrounding areas, background seismicity, depth well and volume of gas storage, etc) this cannot be proved/verified. Moreover, we have to consider the current geodynamic setting of Italy also....and geodetic data reveals that crust beneath Italy is currently deforming in responce to the Eurasia-Nubia convergence. In ligth of this, the naturally occurence of earthquakes have to be expected.

To M. Palano

It isabsolutely wrong that an earthquake triggered the Vaiont landslide. Somebody of your original institution tried to find an earthquake to justify geophysical, geological and operation management errors, but withouth success..

It seems from your statements that all we do can initiate an earthquake.

Be quite, we can survive

To M. Palano

It is absolutely wrong that the Rivara underground gas storage could have triggered the Emilia May 2012 earthqueke for the simple reason that not a single molecule of gas has been injected at Rivara! You can be certain of this.

To all:

We said over and over again that natural earthquakes occurred in the past in the Emilia area (we provided a detailed reconstruction of the seismic history of San Felice sul Panaro, quantifying the multi-century return period of strong earthquakes there), and that natural eartyhquakes will continue to happen regardless of the operations at the proposed underground gas storage site. By the way, according to the data we provided publicly, a strong earthquake was several decades, possibly more than a century, late statistically speaking.

I would like to add that the injection of 3.7 billion cubic meter of methane (some 2.5 million metric tons of compressed gas) 2.5 km deep in the permeable rocks of the Rivara structure would not cause, trigger or anticipate any earthquake, and that a strong natural earthquake would have done no damage whatsoever to the Rivara storage site (surface or subsurface) had the site been already in operation. Preliminary geomechanical data strongly suggests the above, and we engineered an articulated, multidisciplinary appraisal phase (including drilling appriasal wells) to provide in situ geomechanical mesurements and to confirm the above statements.

check Roy Soc London 2012 report on Shale Gas fraccing

Paolo this blog should be linked to the one referred to the fracking as to me (as well as to serious people studying induced seismicity as Zoback, Ellsworth, Giardini ecc ecc) the mechanism triggering any induced seismicity are almost the same whether we are in enhanced geothermal system, oil/gas waste disposal (usually the most massive injections), secondary recovery or hydro-fracturation tout court. It is well known (proven) since 50 years by the oil and gas industry that under certain circumstances (small percentage of the all experiments..), the increased pore pressure resulting from fluid injection , whether for waste disposal (usually the most massive injections), secondary recovery or geothermal energy can trigger small earthquakes and mostly tremors. In most of the case it look like that the fault, was already in quasi critical state, with the stored energy (tectonic stress) then released by changes in stress or hydrogeological conditions and the magnitude of the induced seismic events partly due to the size of any applied stimulation but mainly determined by the strength of the rocks being already tectonically stressed . In all the oil/gas extraction, injection experiments, where induced earthquake has been reported we are speaking about seismicity below the magnitude of 3.5 , and about a small proportion of the total experiments or injection,extraction performed and none of them have produced real damage. The hydrocarbon extraction/injection experiments registered and investigated (both geothermal, waste disposal and fracking) suggests that the water injection or extraction stimulation are the main effects that take the ambient stress within rocks beyond the yield point of the rock. Said that there is a good literature on that subject (co authored by people from Shell, Bp and Statoil ) reporting some earthquake event near the injector or after the gas/oil extraction. I suggest to read the following nice piece of work conerning the il and gas sector: Correlation between hydrocarbon reservoir properties and induced seismicity in the Netherland. Van Eij et al. Engineer Geology, 84, 99-111 (2006); The 7 may 2001 induced seismic event in the Ekofisk oil field, North Sea by Ottemoller et al., Journal of geophysical Research, 110, B10301-10321 (2005).

It is worth to note that none of those events (e.g most of the seismicity in the netherland is induced by the exploration in the Groningen field) prevented the exploration, storage or fluid injection in those countries. Once you know the risk and mechanisms, it is possible to mitigate those events (controlling the poro-perm rock properties, fluid pressure during injection and quantity of water injected)..More need to be investigate on that subject and probably some procedure should imposed during fluid injection experiment of all sort..but scientifically there is no reason to be too much concerned... Concerning Emilia Romagna from what Bencini said no gas storage even happened at the time of the earthquakes...so I hardly see any correlation.

Deep injection clearly does cause earthquakes (e.g. Youngstown, Ohio, Northstar well and the swarms in Arkansas last year, plus the classic sequence at the Rocky Mountain Arsenal 30 years ago). I know of no instances of fracking itself triggering earthquakes that can be felt by humans or are in any way damaging.

We had in Spain a recent example of earthquakes induced by gas injection in an old submarine oil field in the Delta del Ebro region (http://www.proyectocastor.com/). During the last October, more than 350 earthquakes affected the area, reaching a maximum of 4.2 (http://uk.reuters.com/article/2013/10/01/spain-gas-idUKL6N0HR29820131001). Even the people responsible of the project admit that the tremors could have been triggered by the gas injections.

There is an article in 14 November 2013 Nature issue on a related topic and the same story continues in PNAS 19 November 2013 issue. See the attached.

Answers have already been provided here that refer to the effect of groundwater extraction in southern Spain. Elsewhere, examples occur where water storage in dams or deep mining for gold causes earthquakes, for example in South Africa.

One of the emotive issues in this arena relates to fraccing, the practice of pressuring rocks at depth to initiate fractures which help productivity of gas and oil. I have been involved in exploration and production of oil and gas from these so-called “unconventional reservoirs”. In all the examples I have seen, target horizons are from 1000 to 3000 m deep whereas local aquifers are at 20 – 100 m depth. There is therefore 1-3 km of rock between the target area and local water-bearing aquifers.

Secondly, it is true that small earthquakes are triggered, and the detection of these microseismic events is an important tool in reservoir stimulation monitoring. By mapping microseismic events, a view is provided of the extent of the fracture network. With recent innovation, microseismic may be monitored with surface equipment, by using a wide array of passive seismic receivers. Commonly, however, microseismic is only detectable by deploying downhole receivers, in a specially-drilled parallel monitor well. This is an indication of the small scale of the seismicity involved. It is detected only by placing equipment at similar depths, or by deploying a wide array of surface equipment.

The resolution of these systems is up to 10 times greater than provided by publicly available resources such as the US Geological Survey. New surface-based systems allow monitoring of activity prior to reservoir stimulation, during and after. In the past, when detection relied on downhole equipment, it was not possible to compare pre-drilling activity.

David Iacopini, above, mentions Groningen gas field in the Netherlands. Recent news items seem to corroborate some of his points, given that Holland's Economic Affairs Minister has decided to limit production at Groningen Field to ensure that earthquakes are minimized. Apparently the highest historic quake on the Richter Scale was 3.6 (agreeing with the comment above). Tremors began in the area in 1986.

The issue here probably does not relate to individual wells, but rather to the extraction over 50 years of a significant volume of gas. Inflow of the underlying water leg will have partially compensated for this but reduced pressure likely led to earthquakes. If this is the case, it is not unlike earthquakes in the South African Rand some of which relate to removal of rock volume for gold mining.

http://therealnews.com/t2/index.php?option=com_content&task=view&id=31&Itemid=74&jumival=11413

The earthquake (5.9 M) of the May 2012 which struck Emilia Romagna, surely and deterministically, has triggered a communication mediatic event more than as much the gas&oil exploitation in Po plain has triggered the same earthquake.

The 2012 earthquake was statistically predicted and the activated faults were classified as potential, so the hazard of the area clearly has included a similar event (INGV classification). The Po river morphology and the recent geology of the Po valley is the witness of historical but also pre-historical events. The attempt to connect this event to the exploitation of the underground is strumental, anti-scientific and only psycologically justified.

An earthquake, as all catastrophic events, opens an "opportunity windows" for the "science" to communicate the state of the art and what the science and technology are doing to study the origin of these events including the new exploitation technology that, at the moment in my opinion, are the most important experiments to disclose new insights about the earthquake. In fact sometime, only when the human being is able to control the physical systems, which he generates (and controls), can predict the system behaviour and he can use correctly some technologies. The greatest example is the nuclear energy. Probably the construction of nuclear pile will could not be possible without nuclear controlled and uncontrolled experiments performed in the 30's and 40's (excluding the bombs that are other things!!!!! madness).

Several papers on divulgation journals of SEG and EAGE associations (The Leading Edge or First Break) illustrate and deal clearly of induced microseismicity. The scientists of the geophysical prospecting sector have shown and show their results which sometime are very interesting and they are public...sometime more interesting of those of some seismologist. The induced seismicity is not a secret, it can not be hidded, we have perception of an earthquake, furthermore we monitor the seismicity with a completeness threshold of the networks (in Italy) which is below the perception threshold. Probably only the real acceptance by the social communities of these technologies, appropriately regulated on the scientific basis, will induce the public and private scientists to operate together. I really believe that these studies will give a great contribution and probably will open the way to the earthquake prediction. The only way to forecast is to "measure-control" the physical process describing the evolution of the physical-rheological state. Probably as geophysicists we should spend more effort in order to increase the acceptance of the new technologies for the better exploiting of the geo-resources.

I have not yet found the report, but the Ohio Geologic Survey is reporting that for the first time, they have a very strong link between actual hydraulic fracturing (not deep injection disposal) and a moderate earthquake. The mechanism may be reactivation of a previously unknown fault by frac'ing in the Utica shale. I will post a link to the peer-reviewed work as soon as I can find it myself. Here is the news report (and links to others):

http://www.huffingtonpost.com/2014/04/11/ohio-earthquakes-fracking_n_5136110.html

Look at this reference by A. McGarr, "Maximum magnitude earthquakes induced by fluid injection" published in JGR, Solid Earth. 119, 2014 doi:10.1002/2013JB010597

This paper relates volume of fluid injected to the largest earthquake induced.

The full report of the International Commission ICHESE set up to find any possible human influence in the Emilia 2012 eartquake is now available online at the link:

http://ambiente.regione.emilia-romagna.it/geologia/notizie/primo-piano/commissione-ichese-on-line-il-rapporto-integrale

Comments are welcome.

I had a first reading of the report of the International Commission ICHESE set up to find any possible human influence in the Emilia 2012 earthquake (see link in the post above).

I find that three items are missing from such an ambitious report:

- the complete discussion of what humans can do to create earthquakes so large to be felt and to cause damages, or to influence the natural seismicity of the area, distinguished by tectonic regime (compressive, tensional, strike-slip);

- any discussion or quantification of such human effects, particularly influencing effects, in both directions (anticipate or trigger an earthquake, and posticipate or delay an earthquake);

- any discussion or quantification of any threshold that must be exceeded to cause anticipation or posticipation of earthquakes that would have happened anyway, sooner or later.

Without a complete discussion of the range of possibilities for each tectonic regime (and in particular for a compressive stress situation), the Report risks to be seen as a partial and imperfect answer to the question posed (obviously only the second question posed to the ICHESE Commission). For example, not all possible cases are addressed distinctly for tensional and compressional stress regimes (let alone strike-slip), and some analogies are drawn from the inappropriate tectonic regime.

Without discussion or quantification of the potential man-made effects, and most importantly without the discussion of both possible types of influence (anticipation and posticipation), the Report reveals its poor scientific framework. This is the weakest aspect of the Report: not considering what could posticipate an earthquake, but only what could anticipate or trigger it. It seems as the entire Report was conditioned by the pressing need of finding what could be blamed for triggering the destructive earthquake of May 20th, 2012. Finding what could have posticipated the destructive earthquake was probably not as mediatically and politically hot.

Without considering the existence and the quantification of possible thresholds, anything could be blamed, even a butterfly landing at the wrong moment in the wrong field, or a passing geologist sneezing too hard. Thresholds could be a powerful tool to exclude mesmerizing explanations.

Further comments are welcome.

In my opinion the ICHESE commission could not give answers than those given. Responses of common sense and precautional based on saying and not saying. Only with the data at hand we can do more as in the examples cited in the various answers to the question. Exist the data , are they available for the area? Who are the actors involved in the monitoring and why do not they all participated equally in ICHESE commission?. Surely if the data of the Po Plain sites where the exploitation is really performed were available , the commission members did not make a good job.

The real problem now is not to establish blame but to establish the threshold, as it says Roberto Bencini, and this is done with the data at hand, if they exist and are complete (in space time and magnitude for microseismics, experimental and historical seismicity, seismic and other geophysical data, high resolution remote sensing SAR data, surface data and high resolution (in space and time) GPS data, hydrogeological, multiparametric borehole measurements, exploitation and operating technical data, phisical-mechanical data of the reservoir....). Data that the committee ICHESE probably did not have or could not have "completely" because the real players did not participate in the committee itself because they were considered "suspects".

The geography of the exploitation of georesources in the Po Valley sees several actors as "companies", not only private but also public (or in partecipation) if we include the exploitation of geothermal resources in Ferrara, involved in the exploitation and the companies (private, public, academic etc...) involved in the monitoring and control of the induced effects on behalf of the same companies. It is a complex constellation where certainly does not lack the know-how and the expertises, but probably lacking a "minimum common protocol", that can be found only among the companies themselves and the ultimate and third controller (State, DPC, Governement, Regions, Municipalities, Academic and Research institutions?).

Nobody can be either controller and controlled if it is not directly involved in a clear operating procedure that includes and distinguishes between the various responsibilities.

Maybe a commission that is covered by confidentiality between all actors could deliver guidelines that put all of the companies in condition to work and the State to do its part.

Perhaps, dear Roberto, in this condition it could obtain a "treshold" to insert in a possible guidelines for exploitation and monitoring of geo-reservoirs (if ever it will be).

The commissions made by scientists alone , in this research sector, without the partecipation of the companies (with their data and the details on their field operational programs), are almost equal to the sessions of the clairvoyants or dowsers. Probably I would do the same in place of the ICHESE commission members or surely I would renounced to the charge.

As I was the President of the Commission I will will not add further to this discussion but refer you instead to our recent paper on the Uk Shale Gas related events which was selected as a Research Highlight in Nature last week

http://onlinelibrary.wiley.com/doi/10.1002/2014GL062047/abstract

Oil and gas production can induce earthquakes. Fluid injection to stimulate oil and gas production can induce earthquakes. Deep well injection to dispose of waste water from oil and gas production can also induce earthquakes. You can find many resources related to induced earthquakes at the Induced Earthquake Bibliography:

http://www.inducedearthquake.com/