Groningen is the largest onshore gas field under production in Europe. The pressure depletion of the gas field started in 1963. In 1991, the first induced micro-earthquakes have been located at reservoir level with increasing rates in the following decades. Most of these events are of magnitude less than 2.0 and cannot be felt. However, maximum observed magnitudes continuously increased over the years until the largest, significant event with $$M_L=3.6$$ML=3.6 was recorded in 2014, which finally led to the decision to reduce the production. This causal sequence displays the crucial role of understanding and modeling the relation between production and induced seismicity for economic planing and hazard assessment. Here we test whether the induced seismicity related to gas exploration can be modeled by the statistical response of fault networks with rate-and-state-dependent frictional behavior. We use the long and complete local seismic catalog and additionally detailed information on production-induced changes at the reservoir level to test different seismicity models. Both the changes of the fluid pressure and of the reservoir compaction are tested as input to approximate the Coulomb stress changes. We find that the rate-and-state model with a constant tectonic background seismicity rate can reproduce the observed long delay of the seismicity onset. In contrast, so-called Coulomb failure models with instantaneous earthquake nucleation need to assume that all faults are initially far from a critical state of stress to explain the delay. Our rate-and-state model based on the fluid pore pressure fits the spatiotemporal pattern of the seismicity best, where the fit further improves by taking the fault density and orientation into account. Despite its simplicity with only three free parameters, the rate-and-state model can reproduce the main statistical features of the observed activity.

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The occurrence of felt earthquakes due to gas production in Groningen has initiated numerous studies and model attempts to understand and quantify induced seismicity in this region. The whole bandwidth of available models spans the range from fully deterministic models to purely empirical and stochastic models. In this article, we summarise the most important model approaches, describing their main achievements and limitations. In addition, we discuss remaining open questions and potential future directions of development.

" wird seit Anfang der 80 er Jahre in der Personalforschung und in der Managementpraxis diskutiert. In diesem Artikel wird ein Modell zur "Inneren Kündigung" erarbeitet, dass es möglich macht, (1) das Phänomen von ähnlichen Konzepten wie dem Burnout abzugrenzen und (2) im Rahmen empirischer Forschung zu operationalisieren. Das theoretische Modell wurde vom Autor in einer schriftlichen Personalbefragung in einer öffentlichen Verwaltung getestet. In dem Beitrag werden Teilergebnisse aus dem Forschungsprojekt referiert: Sie betreffen die quantitative Verbreitung, die Erscheinungsformen und Ursachen des Phänomens. Zentrale Ergebnisse sind, dass (1) eine verfehlte betriebliche Karrierepolitik eine herausragende Rolle als "Verursacher" für das Problem spielt und dass (2) die betroffene Gruppe von Mitarbeitern sich heterogener darstellt, als in der Literatur angenommen wird.