From Ocean Topography to Flexural Rigidity
This activity has gone through a workshop review process.
This resource was reviewed as part of the May 2009 MARGINS Mini-Lesson Workshop. Each activity received verbal feedback from two participants who had reviewed the activity and activity sheet using these guidelines. Authors revised the activities and activity sheets in response to these comments during the workshop.
This page first made public: Apr 28, 2009
The project is designed to engage students in utilizing the ever-improving bathymetric techniques and data available in GeoMapApp to explore the strength of the oceanic lithosphere as a function of age. Because the data includes both satellite and ship track derived solutions, students have the opportunity to see the utility of each, and travel virtually the world's trenches in search of topographic features. Because not all trenches have pronounced forearc bulges, many are complicated by other topography (e.g. seamounts), and the choices of subduction boundaries are numerous, the module will give students the opportunity to explore quite independently, learning many of the pitfalls of 'real-world' science. This module is designed for upper-level undergraduates taking an Introduction to Geophysics or Quantitative Tectonic-type course.
Context for Use
Students should be able to develop graphs, and optionally perform line-fitting of datasets.
Description and Teaching Materials
Teaching Notes and Tips
- How bathymetry is measured (ship-based and satellite).
- Concept of flexural rigidity and the strength/thickness with age relationship of oceanic lithosphere.
- The value of using proper/SI units and the pitfalls of problems ignoring conversion.
- Spatial comparison of flexural bulge: the existence of, and the spatial variability with relation to plate age and other phenomena
- Concept of error in measurement, interpretation, and modeling.
What do we want students to be able to do?
- Apply simple algebra to real-earth science problems.
- Generate bathymetric profiles and spatial recognition of features and noise.
- Plotting data and reapplying mathematic equations to interpret non-linear relationships.
References and Resources
Information relating to the equations and scientific background for this problem set can be found in Turcotte and Shubert's, Geodynamics, 2nd Edition, Cambridge University Press, 2002.