Induced Earthquakes from Long‐Term Gas Extraction in Groningen, the Netherlands: Statistical Analysis and Prognosis for Acceptable‐Risk Regulation

Abstract

Recently, growing earthquake activity in the northeastern Netherlands has aroused considerable concern among the 600,000 provincial inhabitants. There, at 3 km deep, the rich Groningen gas field extends over 900 km2 and still contains about 600 of the original 2,800 billion cubic meters (bcm). Particularly after 2001, earthquakes have increased in number, magnitude (M, on the logarithmic Richter scale), and damage to numerous buildings. The man‐made nature of extraction‐induced earthquakes challenges static notions of risk, complicates formal risk assessment, and questions familiar conceptions of acceptable risk. Here, a 26‐year set of 294 earthquakes with M ≥ 1.5 is statistically analyzed in relation to increasing cumulative gas extraction since 1963. Extrapolations from a fast‐rising trend over 2001–2013 indicate that—under “business as usual”—around 2021 some 35 earthquakes with M ≥ 1.5 might occur annually, including four with M ≥ 2.5 (ten‐fold stronger), and one with M ≥ 3.5 every 2.5 years. Given this uneasy prospect, annual gas extraction has been reduced from 54 bcm in 2013 to 24 bcm in 2017. This has significantly reduced earthquake activity, so far. However, when extraction is stabilized at 24 bcm per year for 2017–2021 (or 21.6 bcm, as judicially established in Nov. 2017), the annual number of earthquakes would gradually increase again, with an expected all‐time maximum M ≈ 4.5. Further safety management may best follow distinct stages of seismic risk generation, with moderation of gas extraction and massive (but late and slow) building reinforcement as outstanding strategies. Officially, “acceptable risk” is mainly approached by quantification of risk (e.g., of fatal building collapse) for testing against national safety standards, but actual (local) risk estimation remains problematic. Additionally important are societal cost–benefit analysis, equity considerations, and precautionary restraint. Socially and psychologically, deliberate attempts are made to improve risk communication, reduce public anxiety, and restore people's confidence in responsible experts and policymakers.

Seismic assessment of a lab-tested two-storey unreinforced masonry Dutch terraced house

“…These earthquakes are characterised by small-magnitude (M L < 3.5) and occur within a depth of approximately 4 km (van Eck et al 2006). This man-made hazard has progressively become important for the area, especially after the first major event (local magnitude M L = 3.6, peak ground acceleration of 0.08 g) recorded in 2012 in Huizinge (Bourne et al 2015;Vlek 2018).…”

Rise and reduction of induced earthquakes in the Groningen gas field, 1991–2018: statistical trends, social impacts, and policy change

“…This is done against the background of a geophysical hypothesis based on relevant technical documents and further derived from statistical analysis of over 300 well-recorded EQs with magnitude M ≥ 1.5 (Richter) since 1991. In its purpose and methodical approach, the paper links up with recent work by Bourne et al (2014Bourne and Oates 2015), Dempsey and Suckale (2017), Hagoort (2017), Hettema et al (2017), Nepveu et al (2016), and Vlek (2017Vlek ( , 2018.…”

The Sustainability of Fossil Energy Development in Indonesia: Heading to Awry and Backfires Policy?

“…But in providing the desired investment climate, the top priority that must be considered are government regulations. Some other instances of transdisciplinary researches: the treats of oil and gas project to the wilderness, biodiversity, and indigenous peoples in a certain area [14]; long-term gas extraction which induced earthquakes [15]; microbial communities associated with barley growing oil sands reclamation area [16]; negative impact of particulate matter emissions from the expanded oil sands development on the regional air quality and climate change [17]; the consequences of oil and gas development for the distribution of vegetation cover and for species persistence [18]; the impacts of oil and gas operation to the air near the projects that conduct horizontal drilling, hydraulic fracturing, and other drilling and well stimulation technologies which are now used widely in some countries [19]; and the effect of shallow natural gas well structures and associated roads on grassland song bird population declines due to habitat loss and degradation [20]. The aim of those researches are to identify legal instruments or structures realizing an ecosystem approach [21] in responsible experts and policymakers avoiding conflicting approaches to policy-making.…”