You can read the submission here, or download the .pdf

Understanding and Monitoring Induced Seismic Activity

The research project’s aims are to:

• better understand the levels of induced seismic activity that could be associated with unconventional oil and gas activities in Scotland; and 

• better understand the robust regulatory and non-regulatory actions that can be taken to mitigate any noticeable effects on communities.

The Broad Alliance question the narrow remit of this research project and would like to know why geology/hydrogeology are not being assessed more broadly. We are also concerned about the possibility of reliance on the Independent Expert Scientific Panel Report on Unconventional Oil and Gas, published in July 2014. We would argue that this report is limited and now out of date. Furthermore it has been prepared by authors, at least some of whom have affiliations to the oil and gas industry.

We understand that BGS work on behalf of Government at UK level. We disagree with current UK Government policy on Unconventional Gas and hope the BGS report will be genuinely independent.


We understand that there are three types of unconventional gas extraction namely coal-bed methane (CBM), shale and underground coal gasification (UCG). Induced seismicity is generally associated with hydraulic fracturing which is essential for shale gas extraction but also commonly used in coal bed methane extraction.

Induced seismic events have been shown to occur as a result of unconventional oil and gas operations in both the USA and Canada[1]. In the past five years there has been a significant increase in the number of earthquakes occurring in some parts of North America. In the USA most of these events have been linked to wastewater injection into underground wells. However, very recent studies in Canada have revealed a high degree of correlation with the hydraulic fracturing process itself [2]. 

The geology of the UK is complex and the density of faulting in UK shale basins (including specifically the Midland Valley of Scotland) is very much greater than in US shale basins[3]. Earthquakes naturally occur along pre-existing faults where rocks are critically stressed. Seismic events induced by fracking are most likely to occur on these existing faults. To our knowledge no heavily-faulted area has ever been fracked with horizontal wells3. There is therefore good reason for concern.

UCG has also been proposed for the area around the Forth. This largely untested technology has risks of subsidence, seismicity, underground explosions and pollution to groundwater, soil and air. This process is now being banned in Queensland, Australia, following the disastrous pilot scheme in Chinchilla[4]. 

All three types of unconventional gas extraction could take place in Scotland, potentially in proximity to one another within the PEDL133 and Kincardine UCG licence areas.

In addition, the large number of former mine workings in Scotland further complicates matters as these have the potential for instability.

Faults and former mine workings also have the potential to provide pathways for migration of gases and fluids. This is addressed further in the Geology/Hydrogeology section below.


Mine workings

Many areas in Central Scotland lie in high risk areas, as defined by the Coal Authority, due to the presence of former mine workings [5]. The map in Figure 1 shows a section of the Central Belt, showing high risk areas in black hatching. Many of these areas are underneath housing, farms and infrastructure in heavily populated areas. There are also a substantial number of workings which are not known to the Coal Authority because they predate records or were conducted illegally. The Coal Authority defines “high-risk” to mean:

"The Development High Risk Area is the part of the coal mining reporting area which contains one or more recorded coal mining related features which have the potential for instability or a degree of risk to the surface from the legacy of coal mining operations. The combination of features includes mine entries; shallow coal workings (recorded and probable); recorded coal mining related hazards; recorded mine gas sites; fissures and breaklines and previous surface mining sites. New development in this defined area needs to demonstrate that the development will be safe and stable taking full account of former coal mining activities." [our emphasis]

We are very concerned about the implications of induced seismicity, particularly in areas where there is already a high risk of instability due to previous mining activities, and which are often highly populated.


Sensitive Infrastructure

Around the Forth, for example, are a number of sites of sensitive infrastructure including the industrial complex at Grangemouth (refinery, chemical works etc.), the Rosyth Naval Base, the two existing Forth bridges and the new crossing under construction, the Kincardine and Clackmannan bridges and surrounding motorways and railways. There are also a significant number of underground pipelines, particularly in the vicinity of Grangemouth and extending outwards to other parts of the country. These sites would be particularly sensitive to seismic activity and any damage could have serious consequences, particularly given the proximity to large populations. 

The Coal Authority policy statement[6] for UCG states that licences will normally only be considered in areas where there are “no existing Petroleum Licences”, “no identifiable defence installations” and “no other major structures on the seabed”. 

We question if this policy was properly taken into consideration in the awarding of the UCG licence at Kincardine.


Effects on communities

The Broad Alliance is unequivocal in its call for a ban on all forms of unconventional oil and gas extraction. 

One of the aims of this research project is “to better understand the robust regulatory and non-regulatory actions that can be taken to mitigate any noticeable effects on communities”. 

We consider this unsatisfactory in a number of ways.

Firstly the word “robust” is frequently used in relation to regulation, but we are not satisfied that regulation can, or will be, enforced adequately. An example of weak enforcement of regulation was demonstrated when damage occurred to a well casing during the 2011 earthquake at Preese Hall in Lancashire but was not reported to DECC until six months later[7]. There are numerous other examples of poor regulation and enforcement from around the world.

We are unhappy about the assumption that it is sufficient to “mitigate” impacts. Communities, we would argue, do not want to be impacted. In addition we would like to comment on the fact that only “noticeable” effects are being considered here. For one, “noticeable” is a highly ambiguous term, open to multiple interpretations (“noticeable” to whom and how?) and requires specific definition. For two, the allusion here may be intended to denote small earthquakes. However, we respectfully suggest that there are different kinds of impacts on residents and householders. Some are practical such as likely difficulties of obtaining house insurance (even before seismic activity actually occurs) as there is a perceived risk. House values are very likely to drop, potentially significantly[8]. This could prevent people from moving and trap residents, particularly those who have few resources. All these issues could further contribute to anxiety and stress that residents may experience from living in areas targeted for unconventional gas extraction.  

A case can be made that the human rights of local residents would be infringed if unconventional oil and gas extraction was to proceed, including breaches of Article 1 of the first protocol (Protection of Property) and Article 2 (Right to Life) of the European Convention on Human Rights[9],[10].


The Broad Alliance is very concerned that a detailed study of geology/hydrogeology is not part of the research being carried out during the moratorium. We feel that this is a serious omission. 

Dart Energy Public Inquiry

Evidence on geology and hydrogeology formed an important part of the Public Inquiry into Dart Energy’s proposals for Coal Bed Methane extraction at Letham Moss, Falkirk, which took place in March-April 2014. We request that the evidence from this inquiry is studied in detail. All submissions to this inquiry can be found on the DPEA website: . (DPEA case reference PPA‐240‐2032 and PPA‐390‐2029).

In April 2013 Falkirk Council appointed AMEC to carry out an independent review of aspects of Dart Energy’s proposed development, relating to the geological and hydrogeological environment and the assessment of environmental effects. AMEC produced six technical notes over a period of several months and held a number of technical exchanges with Dart Energy and their consultants, RPS.  The AMEC review ended in November 2013 and concluded that two key issues remained unresolved, namely the possibilities of the proposed development drawing water from more than the coal seams, and also encouraging methane migration and promoting fugitive emissions.

Falkirk and Stirling Councils subsequently recommended refusal of planning permission on the basis that Dart Energy had failed to demonstrate that there would be no significant adverse environmental impacts. 

AMEC’s lead technical reviewer on the project, Dr Shaun Salmon, presented evidence at the Public Inquiry as a witness for Falkirk Council.  In summarising the AMEC review he states[11]: “...the RPS decision not to adopt a conservative approach to the impact assessment was problematic, especially the failure to reappraise the geology, faulting and mine workings in the area in sufficient detail, and to accept that, for the purposes of the assessment, faults should have been considered as potential pathways for dewatering and fugitive gas emission effects.”. 

Dr Salmon noted that the proposed development could lead to dewatering of mine workings in the vicinity, causing them to start releasing methane – potentially a dangerous situation.

In their closing submission to the Public Inquiry[12], Falkirk Council highlighted particular problems with the Dart application including inadequate baseline data, lack of transparency in their assessment methodology, errors and inconsistencies in the understanding of the geological environment and an inadequate environmental impact assessment. 

Concerned Communities of Falkirk (CCoF) appointed Prof. David Smythe to give evidence on their behalf. 

Prof. Smythe’s evidence revealed errors and inconsistencies in Dart’s interpretation of the geology of the proposed development area (PDA). Faults were omitted from cross-sections and maps and Prof. Smythe considered this to be significant[13]: “All these faults are significant for consideration of the danger of fugitive methane emission and contamination of groundwater resources, and should not have been omitted from the proposals.”

Prof. Smythe’s evidence discusses the potential for faults to act as conduits for the upward migration of fluids, particularly fugitive methane. He concludes: “the numerous normal faults in the PDA are more likely to act as conduits for fluid flow and fugitive methane than to be barriers to flow. Furthermore, the conduit only has to extend in a vertical sense for 500 m to connect the target coals to the Secondary A aquifer of the Passage Formation. Within the latter, further upward migration will be probable, and once any such fluids reach the Lower Coal Measures there is an additional easy route for upward migrating fluids provided by the old mine shafts”.

In terms of fugitive gas emissions, Dart Energy claimed that this was not possible due to the development of a pressure gradient created during the dewatering process at the well head. However, concerns were raised by both AMEC and CCoF regarding disruption of this pressure gradient (for example by blocked laterals or cessation of dewatering)11,[14].

These concerns were shown to be justified by a recent report commissioned by the Queensland Department of Natural Resources and Mines. This report explains that free gas can potentially migrate large distances (up to10km)[15]: “Towards the margins of the gas field ‐ the pressure gradient is minimal and, if the gas has desorbed, the buoyancy forces may dominate. This can drive the gas vertically and laterally away from the gas field if a pathway exists (fugitive gas). Fractures or high permeability zones along a low dipping geological formation can easily provide such a pathway in the up‐dip direction.”

It should be noted that in the proposed PDA the up-dip of the coal seams are such that Dart Energy’s target seams – the Upper Limestone and Limestone Coal formations – come close to the surface beneath the communities of Cowie and Plean, around 2-3 km to the west of the wellheads. Here, there are extensive abandoned mine workings, and the end of one of Dart’s proposed horizontal boreholes came within a few hundred metres of these. In the context of the Queensland report on the extent of potential free gas migration, these should be considered negligible distances[16].  

Regarding seismicity, Prof. Smythe presented a diagram (Figure 2) which showed that three earthquakes (from BGS data) had occurred in the immediate vicinity of the PDA in the last 30 years[17]. The largest of which was M = 2.6 (local magnitude), larger than the 2011 Blackpool earthquake associated with Cuadrilla’s fracking activities (M = 2.3).  In his evidence at the public inquiry, Prof. Smythe clarified that while an earthquake may be unnoticeable, or trivial, at the surface it can do significant damage to underground workings, such as the deforming of steel casing of Cuadrilla’s well.


Recent research

An important, recent investigation from the USA (Llewellyn et al, May 2015), has shown clear evidence that fracking fluids and gas can travel several kilometres along fractures[18]. 

Prof. Stuart Haszeldine commented on this USA research in his submission to the Lancashire Public Inquiry[19]: “This area [Lancashire] is geologically complex, with many steep (near vertical) faults and fractures. This is like Pennsylvania, but even more fractured.” He concludes: “(A) Deep gas can migrate up to hit the drinking water table (B) Pre-existing steep fractures can be gas and groundwater conduits to move contamination vertically and laterally...”.

Prof. Haszeldine goes on to say: “It is clear that Fracking can impose large stress and fluid pressure onto natural underground systems, far in excess of the present natural conditions. Understanding of natural equilibrium hydrogeology at the present day is essential, but insufficient. Prediction of fluid movement during and after Fracking is of minimal use unless those extreme imposed conditions are simulated.”

Prof. Haszeldine recommended a moratorium to allow scientific investigations to be undertaken.

Prof. Smythe also commented on this recent research in his evidence to the Public Inquiry in Lancashire[20]. He states: “A new paper outlining the history and hydrogeology of a fracking-related contamination incident in NE Pennsylvania, USA, proves beyond reasonable doubt that faults and/or fractures played a crucial part in the contamination of drinking water wells and the Susquehanna River. Prior to this study, incidents of groundwater contamination had been attributed to faulty well construction, whereas faulted geology had always been exonerated.” Prof. Smythe recommended that both Cuadrilla’s planning applications in Lancashire be refused. 

We conclude that the hydrogeology and geology of the UK is complex. Many aspects are not fully understood and require further research. However there is strong evidence to suggest that faults, other geological features and mine workings can act as pathways for the migration of fluids and gases. 

We feel it is inappropriate to pursue the extraction of unconventional oil and gas in Scotland, given the multiple risks.

Comparisons with USA

In order to be economically viable the unconventional gas industry is necessarily intensive. Comparisons with the unconventional gas ‘boom’ in the United States should take account of the very different scale and nature of the landscape and population density here. Figure 3 gives some idea of the difference of scale. 

Petroleum Exploration and Development Licence areas PEDL133 and PEDL162 cover a combined area of 729 km2 of the Central Belt of Scotland. According to figures quoted by INEOS[21] a typical ‘shale gas community’ of 100 km2 would contain around 200 wells – hence these two licence areas alone could contain 1400 shale gas wells. 

In addition, PEDL133 (329 km2) contains an estimated 597 billion cubic feet (bcf) of CBM reserves which may require around 600 wells if it could all be exploited[22].

In our view, the likely impacts on communities and the environment would be entirely unacceptable. 

Figure 3 Comparison of US shale basins with UK shown at the same scale.


Induced seismicity has occurred due to unconventional oil and gas operations and this is not only associated with wastewater injection, but with the hydraulic fracturing itself. The first UK experience of fracking for shale gas, in 2011, resulted in two earthquakes.

Unconventional oil and gas reserves are contained in the most densely populated parts of Scotland, in proximity with sensitive infrastructure. Seismic events could have serious consequences.

UK shale basins have a complex geology and are more densely faulted than those in the US. The Midland Valley of Scotland also has a large number of former mine workings which could be at risk of instability. 

Faults, other geological features and mine workings can act as pathways for the migration of fluids and gases. We are very concerned that geology/ hydrogeology concerns are not being studied more broadly as part of the moratorium research process.

The evidence and concerns that we have presented here form one component of our insistence that unconventional oil and gas extraction should not be permitted.

This statement is submitted by the Broad Alliance, we reserve the right to make any additional comments as new evidence becomes available.



This paper was written before the significant evidence of fracking induced earthquakes in Oklahoma, which has led to the Oklahoma State Government ordering the closure of 37 wells.



[1] Compendium of Scientific, Medical, and Media Findings Demonstrating Risks and Harms of Fracking pp81-95

[2] Gail M. Atkinson et al. “Hydraulic Fracturing and Seismicity in the Western Canada Sedimentary Basin” Seismological Research Letters, Vol. 87, No. 3 May/June 2016

[3] D. Smythe “Objection on grounds of geology and hydrogeology” Planning application No. LCC/2014/0096 by Cuadrilla Bowland Ltd to drill at Preston New Road, Lancashire

[4] “UCG banned immediately in Queensland, Laws to follow, Mines Minister Anthony Lynham says” April 2016,

[5]  Coal Authority Interactive Map Viewer

[6] Underground Coal Gasification, Policy Statement for Licensing by the Coal Authority, 2009

[7] Correspondence between DECC and Cuadrilla,

[8] Shale Gas Rural Economy Impacts (Draft),

[9] Gerard Brophy, “Legal Implications of Application by Dart Energy”, submitted to Falkirk Council in July 2013

[10] The Bianca Jagger Human Rights Foundation, “A Human Rights Assessment of Hydraulic Fracturing and Other Unconventional Gas Development in the United Kingdom”

[11] S. Salmon, Precognition on Behalf of Falkirk Council, Dart Energy Planning Permission Appeal, Letham Moss 

[12] Falkirk Council, Closing Submission, Dart Energy Planning Permission Appeal, Letham Moss, Sections 5 and 6

[13] D. Smythe, Precognition on Behalf of Concerned Communities of Falkirk, Dart Energy Planning Permission Appeal, Letham Moss, p19

[14] Concerned Communities of Falkirk, Closing Submission, Dart Energy Planning Permission Appeal, Letham Moss, Sections 42-44

[15] CSG Compliance Unit, Department ofNatural Resources and Mines, “Potential effects of free gas on bore water supply from CSG development”, March 2016

[16] Concerned Communities of Falkirk, “Representation in relation to G20”, Dart Energy Planning Permission Appeal, Letham Moss

[17] D. Smythe, Rebuttal Precognition, on Behalf of Concerned Communities of Falkirk, Dart Energy Planning Permission Appeal, Letham Moss

[18] Llewellyn et al, “Evaluating a groundwater supply contamination incident attributed to Marcellus Shale gas development”, Proc. Natl. Acad. Sci. 2015

[19] S. Haszeldine, “Cautionary comments on groundwater contamination relating to high volume fracking, derived from recent published USA research”, Planning application No. LCC/2014/0096 (Preston New Road) and LCC/2014/0101 (Roseacre Wood) 

[20] D. Smythe, “Additional comments relevant to planning applications by Cuadrilla Bowland Ltd”, Planning application No. LCC/2014/0096 (Preston New Road) and LCC/2014/0101 (Roseacre Wood) 

[21] Shale Gas: The Game-Changer