Stress and Strain
Compiled by Monica Bruckner at the Science Education Resource Center (SERC), Carleton College.
The following visualizations illustrate stress and strain. Visualizations include simple animations, experimental models, visual output from numerical models, as well as static diagrams and photos.We also have additional structural geology visualization collections
How Do Rocks Respond to Stress? (more info) This tutorial is part of the series of investigations and visualizations on the Exploring Earth website, which was designed to accompany 'Earth Science,' a high school textbook. This tutorial on stress covers brittle and ductile deformation, stress simulations, and geologic structures. Very clear animations and field photographs illustrate this tutorial. Students can move the cursor over each photograph to see an outline of the geologic structure shown.
World Stress Map Project (more info) The World Stress Map (WSM) is one of the fundamental geo-databases. It is maintained and extended at the Geophysical Institute of Karlsruhe University as the research project "Weltkarte der tektonischen Spannungen" of the Heidelberg Academy of Sciences and Humanities. The WSM database contains information on the contemporary tectonic stress state (e.g. orientation and magnitude) in the Earth's crust. The WSM was originally compiled by a group headed by Mary Lou Zoback as part of the International Lithosphere Program (ILP). Stress data can be downloaded, viewed using WSM maps, or used to generate custom maps with the WSM CASMO map-making software.
Visualizing Structural Geology (more info)
This site contains visualizations for stress and strain analysis. These visualizations allow the student to create and view detailed illustrations and animations of the mathematics of stress and strain. Topics include lithostatic stress, the stress tensor, the Mohr Circle of stress, pure and simple shear, the principle strain directions, incremental versus finite strains, strain path dependencies, and tools for calculating the various strain parameters. The site also features exam review questions, and several visualizations that may be useful for classroom lectures, such as a three point problem, apparent dip, and projecting circles on stereonets.
Rod Holcombe Structural Geology Animation Library (more info) This site features several short animations of rock deformation. Animations are grouped by type, including flow and strain, shear zones, and fault-bend fold animations. The site contains both animated GIFs and QuickTime movies that can be viewed directly with a web browser.
Map Tools for EarthScope Science and Education: Strain Rate Models (more info) This collection includes movies, GIS data, and Google Earth KMZ files that represent models of finite deformation in southern California through time. The site also includes student activities using Google Earth and GIS. These animations were generated using geologic and geodetic observations and illustrate predictions of both horizontal and vertical changes through time. The movies can be used to present an overview of specific relationships between the North American and Pacific Plates, and to exemplify general plate tectonics phenomena. Using the GIS and Google Earth data, students can measure the size and direction of movement of points marked by city names, and changes in the positions of faults over time.