Karsten Reiter

Prediction of the present-day stress field in the Australian continental crust using 3D geomechanical–numerical models

ABSTRACT The Australian continent has an enigmatic present-day stress pattern with considerable regional variability in maximum horizontal stress (SHmax) orientations. Previous attempts to estimate the Australian SHmax orientation with geomechanical–numerical models indicate that plate boundary forces provide the major controls on the contemporary stress orientations. However, these models do not satisfactorily predict the observed stress orientation in major basins throughout eastern Australia, where the knowledge of the present-day crustal stresses is of vital importance for development and management of different types of geo-reservoirs. In addition, a new comprehensive stress-data compilation in Australia, which contains 2150 data records and is the key dataset for model calibration, provides motivation to construct a new geomechanical–numerical model for Australia. Herein, we present a 3D geomechanical–numerical model that predicts both the SHmax orientation and the relative stress magnitudes throughout the Australian continent. Our best-fit model, with mean absolute deviation of 15°, is in good agreement with observed SHmax orientations and the stress regime in most areas, and shows a much better fit in areas where the stress pattern was unable to be predicted by previous published attempts. Interestingly, the best-fit model requires a significant push from the western boundary of Australian continental model, which is possible supporting evidence for the east–west-oriented mantle drag postulated by state-of-the-art global convection models, or may be generated by the excess of gravitational potential energy from Tibetan Plateau, transferred through the Indo-Australian Plate. Hence, our modelling results provide a good first-order prediction of the stress field for areas where no stress information is currently available and can be used to derive initial and boundary conditions for local and reservoir-scale 3D geomechanical models across Australia.

Mining-Induced Stress Transfer and Its Relation to a \text{M}_w 1.9 Seismic Event in an Ultra-deep South African Gold Mine

On 27 December 2007, a Mw\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}

Stress Field Sensitivity Analysis at a Reservoir Scale (Northern Switzerland) Using Numerical Geomechanical Modelling

\text{M}_w

The interaction of two indenters in analogue experiments and implications for curved fold-and-thrust belts

\end{document} 1.9 seismic event occurred within a dyke in the deep-level Mponeng Gold Mine, South Africa. From the seismological network of the mine and the one from the Japanese–German Underground Acoustic Emission Research in South Africa (JAGUARS) group, the hypocentral depth (3,509 m), focal mechanism and aftershock location were estimated. Since no mining activity took place in the days before the event, dynamic triggering due to blasting can be ruled out as the cause. To investigate the hypothesis that stress transfer, due to excavation of the gold reef, induced the event, we set up a small-scale (450×300×310m3)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}

3-D geomechanical–numerical model of the contemporary crustal stress state in the Alberta Basin (Canada)

(450\times 300\times 310\;\text{m}^3)

Stress map of the Mediterranean and Central Europe 2016

\end{document} high-resolution three-dimensional (3D) geomechanical numerical model. The model consisted of the four different rock units present in the mine: quartzite (footwall), hard lava (hanging wall), conglomerate (gold reef) and diorite (dykes). The numerical solution was computed using a finite-element method with a discretised mesh of approximately 106\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}