• Outcomes: To develop a deeper understanding of the theory of isostasy and how it controls the surface elevation of plates. To develop a deeper understanding of the dynamic of mid-oceanic-ridges. To be able to evaluate the magnitude of the Ridge-Push force and that of any other gravitational forces acting between two lithospheric columns of contrasted elevations and/or density structures.
• Generic skills:  Problem solving ability, computational skills, and analytical skills.
  
• Assumed background knowledge:  Basic knowledge on isostasy, lithostatic pressure and gravitational potential energy (check out your lecture notes) and Year 12 Mathematics.
  
• Tools you may want/need to use:  MatLab or LiveMath, calculator...
  
• Reading:  Turcotte & Schubert: Geodynamics
  

Submission details
Individual report due next wednesday.

Some fundamentals
On the theory of isostasy:  The theory of isostasy assumes that there is a depth called "the compensation level" under which the stress is lithostatic (isotropic stress) therefore only related to the weight of the rock column above. In other terms there is no lateral variation of lithostatic pressure (also called confining pressure) along a given gravitational equipotential surface. It is isostasy that dictates the elevation of lithospheric plates.

On the gravitational potential energy and the gravitational force:  Above the compensation level, lateral variations of density produce lateral contrasts in Gravitational Potential Energy (GPE) responsible for an horizontal force called the gravitational force (Fg, a volume force). The gravitational potential energy of a column of lithosphere corresponds to vertical integration, down to the compensation level, of the lithostatic pressure profile. The gravitational force per unit length (Nm^-1) that two lithospheric columns apply to each other is equal to the difference in their GPE.