The characterisation of linked physical properties such as elasticity, strength and permeability from outcrop to crustal scales is complicated by heterogeneity, fabric anisotropy and damage in so-called “intact rock” and by geological structure and inherited fracturing in the bulk “rock mass”. Rocks can behave as continuous or discontinuous media depending on the scale of consideration and the occurrence of discrete structures (e.g. fault zones). Moreover, rock properties and inherited geological features constrain mechanical damage processes resulting in rock mass weakening, altered permeability and hydro-mechanical coupling between rock and fluids, development of brittle shear zones, and time-dependent behavior (creep).
Despite major experimental, theoretical and modelling advances, a remaining future goal is to develop meaningful, testable methods and models that allow us to quantify the relationships between fabrics and fractures related to the geomechanical behavior of rocks on different scales and in different environmental conditions (P, T, stress, strain rate, fluids). This is critical in order to unravel the complex evolution and dynamics of the Earth’s crust, and develop predictive capabilities for geohazard and energy applications.
In this session we will bring together researchers from different communities, working on problems related to quantifying the hydro-geomechanical properties and behavior of rock masses considered either as continua or discontinua. We will explore their geological controls from the micro- to macro-scale, in a range of crustal environments and geological and geohazard applications (e.g. understanding fluid movement and hydrothermal systems at volcanoes, fluid pressure and damage evolution within fault zones. rock slope instability and related geomorphic impacts, fractured reservoir exploitation, subsidence due to drainage, induced seismicity), using experimental and numerical approaches in the laboratory and the field. We especially welcome studies that adopt novel approaches and combined methodologies.

IMPORTANT NOTICE: Please, send registration info (your name and e-mail address to Marina Karsanina: marina.karsanina@gmail.com), this is necessary to estimate the number of participants and redistribute training materials and software prior to the course!
Also note that you will need a laptop (preferably fully charged) for practical work.

Motivation: In numerous scientific areas dealing with flow and transport in porous media such as hydrology, soil and rock physics, petroleum engineering, X-ray microtomography (XCT) is the key tool to obtain information on rock/soil structure under study. If structural information is obtained, one can utilize so-called pore-scale modelling to simulate fluid flow directly in the pore space of the 3D porous media images. Even the simplest workflow to simulate single phase flow and compute permeability requires a number of steps, image processing including segmentation and solution of the Stokes equation in 3D geometry being the most critical or time consuming. Recent developments in the field of pore-scale modelling allow to perform decent simulations using a modern personal computer, but such tools are still not widespread in routine research work.

Aim: To provide an introduction and basic tools to perform all necessary steps from X-ray microtomography images to single-phase flow simulations.

Plan: 1) Introduction to 3D imaging, image processing and pore-scale modelling (20 min.); 2) Overview of available software/solutions and typical problems (10 min.); 3) Description of solutions developed by our group and available to the public (10 min.); 4) Hands-on image processing and segmentation (30 min.); 5) Hands-on single phase flow modelling (20 min.); 6) Interpretation and visualization of results (20 min.); 7) Interactive session with questions (5 min.).
For all hands-on sessions you will use free software developed by our research group (FaT iMP) and some other freely available packages. All necessary materials, including sample XCT images, will be distributed by organizers prior to the course.

What will you learn: 1) The basics of porous media imaging, 2) how to prepare and crop XCT images for pore-scale modelling, 3) how to segment images using current state-of-the-art local thresholding techniques, 4) how to simulate single phase flow and compute permeability of porous media samples from 3D images.
At the end of the course you will be able to simulate single-phase flow based on grey-scale XCT images of porous media.

Public information:
1) Introduction to 3D imaging, image processing and pore-scale modelling (20 min.); 2) Overview of available software/solutions and typical problems (10 min.); 3) Description of solutions developed by our group and available to the public (10 min.); 4) Hands-on image processing and segmentation (30 min.); 5) Hands-on single phase flow modelling (20 min.); 6) Interpretation and visualization of results (20 min.); 7) Interactive session with questions (5 min.).
For all hands-on sessions you will use free software developed by our research group (FaT iMP) and some other freely available packages. All necessary materials, including sample XCT images, will be distributed by organizers prior to the course.

IMPORTANT NOTICE: Please, send registration info (your name and e-mail address to Marina Karsanina: marina.karsanina@gmail.com), this is necessary to estimate the number of participants and redistribute training materials and software prior to the course!
Also note that you will need a laptop (preferably fully charged) for practical work.

The advent of novel technologies have boosted our capability of acquiring new evidences that faults behavior is various and extremely sensitive to a large number of parameters. These evidences are supported in natural earthquakes by the occurence of a large pletora of events spanning from slow to fast earthquakes, precursory slips, non volcanic tremors and low frequency earthquakes. The aim of this session is to convey interdisciplinary studies on fault behaviour and processes controlling the propagation of slip instabilities in rocks, granular materials and/or laboratory analogs; we invite contributions at the frontiers between Rock Mechanics, Models, Seismology, Tectonics and Mineralogy dealing with either slow, fast or transient evolution of earthquakes and earthquake sequences in shallow and deep environments; we welcome studies performed at the laboratory and field scale, providing insights on earthquake evolution and/or constraining observed seismological statistical laws like Omori’s and Gutenberg-Richter’s; we welcome innovative techniques that help the observations and take advantage of high-speed imaging and continuous acoustic emission streaming data.

The mechanics of earthquakes is controlled by a spectrum of processes covering a wide range of length scales, from tens of kilometres down to few nanometres. For instance, while the geometry of the fault/fracture network and its physical properties control the global stress distribution and the propagation/arrest of the seismic rupture, earthquake nucleation and fault weakening is governed by frictional processes occurring within extremely localized sub-planar slipping zones. The co-seismic rheology of the slipping zones themselves depends on deformation mechanisms and dissipative processes active at the scale of the grain or asperity. If this is the case of shallow earthquakes, the nucleation of intermediate and deep earthquakes remains enigmatic since it occurs at elevated ambient pressure-temperature conditions which should favour plastic deformation and suppress frictional processes. Though, recent studies on fault rocks of Earth’s lower crust and upper mantle reveal microstructures comparable to those associated with co-seismic slip and off-fault damage in brittle rocks. The study of such complex multiscale systems requires an interdisciplinary approach spanning from structural geology to seismology, geophysics, petrology, rupture modelling and experimental rock deformation. In this session we aim to convene contributions dealing with different aspects of earthquake mechanics at various depths and scales such as:
· the thermo-hydro-mechanical processes associated to co-seismic fault weakening based on rock deformation experiments, numerical simulations and microstructural studies of fault rocks;

· the study of natural and experimental fault rocks to investigate the nucleation mechanisms of intermediate and deep earthquakes in comparison to their shallow counterparts;

· the elastic, frictional and transport properties of fault rocks from the field (geophysical and hydrogeological data) to the laboratory scale (petrophysical and rock deformation studies);

· the internal architecture of seismogenic fault zones from field structural survey and geophysical investigations (e.g. seismic, electric and electromagnetic methods);

· the modeling of earthquake ruptures, off-fault dynamic stress fields and long-term mechanical evolution of realistic fault networks;

· the earthquake source energy budget and partitioning between fracture, friction and elastic wave radiation from seismological, theoretical and field observations.

· the interplay between fault geometry and earthquake rupture characteristics (e.g. coseismic slip and rupture velocity distribution) from seismological, geodetic, remote sensed or field observations;

We particularly welcome novel observations or innovative approaches to the study of earthquake faulting. Contributions from early career scientists are solicited.

Solicited oral presentation: Matthew Tarling (University of Otago)

Thermal, hydraulic, mechanical and chemical (THMC) processes in geological settings are of increasing interest in different geo-scientific fields. This is especially the case within current research applied to exploration and usage of natural and mineral resources from the underground. This session is intended as a scientific platform to present and discuss studies focused on various kinds of processes relevant for geo-energy related applications. These comprise, but are not limited to, enhanced oil recovery, aquifer storage, and hydro- and enhanced geothermal applications. Therefore, we invite contributions ranging from innovative laboratory experiments, analytical solutions and mathematical model applications to the discussion of an improved way to understand the history, current state as well as future performance of reservoirs.
More specifically, we welcome contributions dealing with analysis and quantification of: (i) fluid flow, permeability, fluid conductivity; (ii) electrical properties, conductivity, resistivity and permittivity in both real and complex domains; (iii) heat flow, geothermal states, thermal conductivity and diffusivity; (iv) transport of energy by elastic waves, their velocities and the dispersion of compression, shear and other types of elastic waves; and (v) mechanical properties of fractured and intact rock materials. Contributions on coupling mechanisms of THMC-processes in fractured and intact reservoir rocks are of special interest.
This session is intended to provide an overview of current research activities in this field. By discussing advances and challenges in quantifying coupled physical processes in geological settings and their implications it aims to stimulate new ideas for future work.

The goal of this session is to reconcile short-time/small-scale and long-time/large-scale observations, including geodynamic processes such as subduction, collision, rifting or mantle lithosphere interactions. Despite the remarkable advances in experimental rock mechanics, the implications of rock-mechanics data for large temporal and spatial scale tectonic processes are still not straightforward, since the latter are strongly controlled by local lithological stratification of the lithosphere, its thermal structure, fluid content, tectonic heritage, metamorphic reactions and deformation rates.

Mineral reactions have mechanical effects that may result in the development of pressure variations and thus are critical for interpreting microstructural and mineral composition observations. Such effects may fundamentally influence element transport properties and rheological behavior.
Here, we encourage presentations focused on the interplay between metamorphic processes and deformation on all scales, on the rheological behavior of crustal and mantle rocks and time scales of metamorphic reactions in order to discuss
(1) how and when up to GPa-level differential stress and pressure variations can be built and maintained at geological timescales and modelling of such systems,
(2) deviations from lithostatic pressure during metamorphism: fact or fiction?,
(3) the impact of deviations from lithostatic pressure on geodynamic reconstructions.
(4) the effect of porous fluid and partial melting on the long-term strength.
We therefore invite the researchers from different domains (rock mechanics, petrographic observations, geodynamic and thermo-mechanical modelling) to share their views on the way forward for improving our knowledge of the long-term rheology and chemo-thermo-mechanical behavior of the lithosphere and mantle.

The presence of fractures, whether natural or induced, has become increasingly important in recent years in the exploitation of Earth’s natural resources. Especially in rocks that have a low matrix permeability, the presence of fractures is critical for reaching flow rates sufficient for economic hydrocarbon production and heat extraction for geothermal reservoirs. Better prediction of subsurface fracture arrangements and their mechanical and flow response have become an increasingly relevant field of research.
We propose here a multi-disciplinary session on the arrangement and mechanical evolution of natural and induced fracture networks and their response to fluid flow in low-permeability rocks on a multitude of scales (from pore-scale to basin-scale). We encourage submissions from experimental, numerical and field studies on fracture network formation and control on fluid flow of naturally and hydraulically fractured systems. Also studies that address the role of fractures on both shale gas and tight geothermal reservoir application cases are welcomed. We especially encourage early-career scientists to present their work in this session.

Geological and geophysical data provide quantitative information which permit the advancement of our understanding of the present, and past, interior of the Earth. Examples of such processes span from the internal structure of the Earth, plate kinematics, composition of geomaterials, estimation of physical conditions and dating of key geological events, thermal state of the Earth to more shallow processes such as reservoir geomechanics, or nuclear waste storage.

A quantitative understanding of the dynamics and the feedbacks between geological processes requires the integration of geological data with process oriented numerical models. Innovative inverse methods, linking forward dynamic models with observables, are topics of growing interest within the community. Improving our knowledge of the governing physical parameters can thus be addressed while reconciling models and observables.

Resolving the interactions between various processes occurring at scales differing from each other over several orders of magnitude in space and time represents a computational challenge. Hence, simulating such coupled, nonlinear physics-based forward models requires both the development of new approaches and the enhancement of established numerical schemes.

The majority of geological processes combine several physical mechanisms such as hydrological, thermal, chemical and mechanical processes (e.g. thermo-mechanical convection). Understanding the tight couplings among those processes represents a challenging and essential research direction. The development of novel numerical modelling approaches, which resolve multi-physics feedbacks, is vital in order to provide accurate predictions and gain deeper understanding of geological processes.

We invite contributions from the following two complementary themes:

#1 Computational advances associated with
- alternative spatial and/or temporal discretisations for existing forward/inverse models
- scalable HPC implementations of new and existing methodologies (GPUs / multi-core)
- solver and preconditioner developments
- code and methodology comparisons (“benchmarks”)
- open source implementations for the community

#2 Physics advances associated with
- development of partial differential equations to describe geological processes
- inverse and adjoint-based methods
- numerical model validation through comparison with natural observations and geophysical data
- scientific insights enabled by 2D and 3D modelling
- utilisation of coupled models to address nonlinear interactions

Numerous cases of induced/triggered seismicity have been reported in the last decades as a result of the increasing interest in fluid injection/extraction projects related to geo-resources exploration. When such seismicity is felt by the population, it can negatively affect public perception of geo-energies and may lead to the cancellation of important projects. Furthermore, large earthquakes may jeopardize wellbore stability and damage surface infrastructure. Thus, a key issue is to better understand how to monitor and model the processes leading to seismicity, in order to facilitate the development of effective and reliable forecasting methodologies during deep underground exploitation.
Given the complexity of induced seismicity processes and their interdisciplinary nature, understanding the triggering mechanisms implies to take into account coupled thermo-hydro-mechanical-chemical processes.
In this session, we invite contributions from research aimed at understanding such processes during exploitation of deep underground resources, including hydrocarbon
extraction, wastewater disposal, geothermal
energy exploitation, hydraulic fracturing, gas storage and production, mining, and reservoir impoundment for hydro-energy.
We particularly encourage novel contributions based on laboratory and underground near-fault experiments, numerical modelling, spatio-temporal variations of physical parameters and seismicity, and fieldwork, covering both theoretical and experimental aspects of induced and triggered seismicity at multiple spatial and temporal scales.

Hydraulic stimulation is a well-operation that aims at enhancing fluid flow at depth. It is applied to exploit unconventional hydrocarbon reservoirs with low permeability and deep geothermal resources. Induced earthquakes frequently accompany the injection of fluids into boreholes potentially leading to damage to infrastructure at the surface and thus generally raising public concern. Damage caused by such events have already terminated Enhanced Geothermal Energy projects in South Korea and Switzerland. Hence, finding safe stimulation methods is critical for future use and public acceptance of geothermal energy projects and potential other forms of energy extraction from the underground. A range of stimulation techniques have been developed to increase the permeability of low-permeable reservoirs, however, our understanding of the processes involved in the formation of hydrofracs and hydroshears and the effectiveness of these operations regarding flow enhancement are still rather limited. A series of successful mine-back experiments have been performed in a range of underground laboratories in Europe. For this session, we invite presentations covering the full range of rock mechanics experiments, underground laboratory testing, and field-scale operations aiming at improving the fundamental understanding of stimulation operations.

Grain size or grain size distributions (GSDs) play a major role in many fields of geoscience research. Paleopiezometry is based on the relation between grains size and flow stress. Environments of depositions have typical GSDs. Time temperature and grain size have characteristic relations during static grain growth. Fracture processes are associated with the fractal dimension of the GSD they produce, etc.. In all these cases, meaningful interpretations rest on the correct acquisition and quantification of grain size data.

The aim of this short course is to discuss with participants the following questions

1) when do we need grain size analysis ? what is it good for ? what are the limitations ?
2) how do we identify grains? what are the criteria for segmentation?
3) how do we define reliable measures for grain size ?
4) what do we mean by 'mean grain size' ?
5) how much data do we need ?
6) and what about errors ?

Handouts will be available in electronic form.

Please send email if you want to participate (renee.heilbronner@unibas.ch)

Image analysis has become a standard tool for shape and fabric analysis of a wide range of rock types (sedimentary, magmatic and metamorphic) and for microstructure analysis of natural and experimental samples at all scales. From quantified shape fabrics, rock properties may be inferred and related to the processes that created them.

In the first half of the short course, some basic techniques are outlined, in the second half, there will be demonstrations of selected applications.

The following topics will be covered:
1) image acquisition and pre-processing
2) segmentation: from picture to bitmap
3) shape analysis of individual grains or particles
4) fabric and strain analysis: looking at volumes and surfaces
5) analysis of spatial distribution: from clustered to random to ordered

Demonstrations will be made using ImageJ and Image SXM. Note, however, that familiarity with either of these programs is not required. - This is a short course, not a workshop.

Please send email if you want to participate (renee.heilbronner@unibas.ch)

This course is aimed at anyone who wants to better understand the origin of physical anisotropy in rocks. The principles and methods learned in the course can be applied to any anisotropy that is described by tensors and depends on the bulk properties of a sample rather than being dominated by grain boundary properties. As such, this course is relevant for researchers working in a range of fields, including those investigating seismic anisotropy, magnetic fabrics, or anisotropy of thermal conductivity.
We will discuss the intrinsic anisotropy of single crystals, the interplay of crystallographic preferred orientation and single crystal anisotropy to control the anisotropy in rocks, and give an introduction to how anisotropic physical properties can be predicted in rocks, including an introduction to the freely available Matlab toolbox MTex.
Participants will leave the course with a thorough and detailed understanding of factors controlling anisotropy in rocks, and have the necessary background to quantitatively predict anisotropy based on their own texture datasets or demonstration data sets.