The future of conferences: lessons from Europe's largest online geoscience conference

In the early months of 2020, as the novel coronavirus (COVID-19) swept across the globe, millions of people were required to make drastic changes to their lives to help contain the impact of the virus. Among those changes, scientific conferences of every type and size were forced to cancel or postpone in order to protect public health. Included in these was the European Geosciences Union (EGU) 2020 General Assembly, an annual conference for Earth, planetary, and space scientists, scheduled to be held in Vienna, Austria, in May 2020. After a 6-week period of changing the format to an online alternative, attendees of the newly designed EGU20: Sharing Geoscience Online took part in the first geoscience conference of its size to go fully online. This paper explores the feedback provided by participants following this experimental conference and identifies four key themes that emerged from an analysis of the following questions: what did attendees miss from a regular meeting, and to what extent did going online impact the event itself, both in terms of challenges and opportunities? The themes identified are “connecting”, “engagement”, “environment”, and “accessibility”. These themes include concepts relating to discussions of the value of informal connections and spontaneous scientific discovery during conferences, the necessity of considering the environmental cost of in-person meetings, and the opportunities for widening participation in science by investing in accessibility. The responses in these themes cover the spectrum of experiences of participants, from positive to negative, and raise important questions about what conference providers of the future will need to do to meet the needs of the scientific community in the years following this coronavirus outbreak

Analogue modelling of basin inversion: a review and future perspectives

Basin inversion involves the reversal of subsidence in a basin due to compressional tectonic forces, leading to uplift of the basin's sedimentary infill. Detailed knowledge of basin inversion is of great importance for scientific, societal, and economic reasons, spurring continued research efforts to better understand the processes involved. Analogue tectonic modelling forms a key part of these efforts, and analogue modellers have conducted numerous studies of basin inversion. In this review paper we recap the advances in our knowledge of basin inversion processes acquired through analogue modelling studies, providing an up-to-date summary of the state of analogue modelling of basin inversion. We describe the different definitions of basin inversion that are being applied by researchers, why basin inversion has been historically an important research topic and what the general mechanics involved in basin inversion are. We subsequently treat the wide range of different experimental approaches used for basin inversion modelling, with attention to the various materials, set-ups, and techniques used for model monitoring and analysing the model results. Our new systematic overviews of generalized model results reveal the diversity of these results, which depend greatly on the chosen set-up, model layering and (oblique) kinematics of inversion, and 3D along-strike structural and kinematic variations in the system. We show how analogue modelling results are in good agreement with numerical models, and how these results help researchers to better understand natural examples of basin inversion. In addition to reviewing the past efforts in the field of analogue modelling, we also shed light on future modelling challenges and identify a number of opportunities for follow-up research. These include the testing of force boundary conditions, adding geological processes such as sedimentation, transport, and erosion; applying state-of-the-art modelling and quantification techniques; and establishing best modelling practices. We also suggest expanding the scope of basin inversion modelling beyond the traditional upper crustal "North Sea style " of inversion, which may contribute to the ongoing search for clean energy resources. It follows that basin inversion modelling can bring valuable new insights, providing a great incentive to continue our efforts in this field. We therefore hope that this review paper will form an inspiration for future analogue modelling studies of basin inversion

A systematic comparison of experimental set-ups for modelling extensional tectonics

Analogue modellers investigating extensional tectonics often use different machines, set-ups and model materials, implying that direct comparisons of results from different studies can be challenging. Here we present a systematic comparison of crustal-scale analogue experiments using simple set-ups simulating extensional tectonics, involving either a foam base, a rubber base, rigid basal plates or a conveyor base system to deform overlying brittle-only or brittle-viscous models. We use X-ray computed tomography (CT) techniques for a detailed 3-D analysis of internal and external model evolution. We find that our brittle-only experiments are strongly affected by their specific set-up, as the materials are directly coupled to the model base. Experiments with a foam or rubber base undergo distributed faulting, whereas experiments with a rigid plate or conveyor base experience localized deformation and the development of discrete rift basins. Pervasive boundary effects may occur due to extension-perpendicular contraction of a rubber base. Brittle-viscous experiments are less affected by the experimental set-up than their brittle-only equivalents since the viscous layer acts as a buffer that decouples the brittle layer from the base. Under reference conditions, a structural weakness at the base of the brittle layer is required to localize deformation into a rift basin. Brittle-viscous plate and conveyor base experiments better localize deformation for high brittle-to-viscous thickness ratios since the thin viscous layers in these experiments allow deformation to transfer from the experimental base to the brittle cover. Brittle-viscous-base coupling is further influenced by changes in strain rate, which affects viscous strength. We find, however, that the brittle-to-viscous strength ratios alone do not suffice to predict the type of deformation in a rift system and that the localized or distributed character of the experimental set-up needs to be taken into account as well. Our set-ups are most appropriate for investigating crustal-scale extension in continental and selected oceanic settings. Specific combinations of set-up and model materials may be used for studying various tectonic settings or lithospheric conditions. Here, natural factors such as temperature variations, extension rate, water content and lithology should be carefully considered. We hope that our experimental overview may serve as a guide for future experimental studies of extensional tectonics

Sensitivity of shear zones in orogenic wedges to surface processes and strain softening

décembre 19931993/12 (N49)-1993/12